Explanations and implications for reminders

Several potential mechanisms might explain variations in levels of attendance by source of original appointment. First, the identity of the person/department/service that initiates the making of an appointment (invites the patient to the appointment) may influence patient perceptions that attendance at the appointment will positively contribute to well-being and/or that non-attendance will result in negative consequences. It may also be hypothesised that the source of the original appointment could influence patient perceptions that attendance is the morally ‘right thing’ to do, for instance if the appointment invitation comes from a health-care professional with whom the patient has a pre-existing relationship.

In addition, however, associations between the source of a referral/original appointment and attendance may relate to differences in the knowledge level of the practitioner about how likely a patient is to attend, perhaps related to knowledge of personal circumstances and/or readiness to engage with the particular treatment/care on offer. For example, Booth and Bennett⁸⁹ in their study of a specialist alcohol treatment centre in the UK suggest that ‘it is possible that since GPs tend to have a longer-standing professional relationship with their clients than other referral sources, they may be better placed to assess patient readiness to seek help for an alcohol problem’. In this way, some practitioners may act as gate-keepers/demand managers by not offering referrals to patients they believe will not turn up anyway.

Differential attendance rates by source of referral may also reflect a higher degree of involvement of the patient in the decision to seek the appointment and the scheduling of that appointment. For instance, hospital referrals made by a GP are likely to result from a consultation initiated by a patient in response to some perceived need and may also allow for involvement of the patient in the scheduling of the appointment, whereas referrals between departments may not involve the patient to the same degree.

In addition, higher attendance rates associated with appointment invitations emanating from general practices may reflect more up-to-date and far-reaching patient contacts, so that the appointment information may simply be received by more patients when it comes from some sources rather than others.

The available evidence does not allow a detailed exploration of these various potential mechanisms and does not provide consistent evidence to inform decisions regarding the source of reminders that are likely to be most effective.

Time of day

Three studies, all with reasonable designs and sample sizes – a RCT including 3899 patients, a prospective study and a case–control design – reported no evidence that the time of day of the original appointment has an effect on attendance.

A RCT in Portugal⁶³ included 3899 patients of various ages across various outpatient clinics and found that looking at the overall attendance data (for reminder and control groups) the time of day (morning or afternoon) was not a statistically significant variable with respect to non-attendance (p > 0.05). A UK study based in a specialist alcohol treatment centre⁸⁹ undertook multivariate analysis of patient characteristics of non-repliers (n = 100), non-attenders (n = 100) and attenders (n = 100), and also included a trial element that examined the effect of a telephone reminder. The authors found that the time of the appointment (morning or afternoon) was not an independent predictor variable associated with attendance and was the last to emerge from the logistic regression equation. In addition, it was not significant over and above age and distance. The authors were somewhat surprised by this finding and speculated that there may have been a chance combination of older patients with shorter distances to travel to morning appointments. A UK study¹²¹ exploring attendance behaviour at a gynaecology clinic with an ethnically diverse and deprived patient population employed a case–control design to explore the association of morning compared with afternoon clinic attendance (compared characteristics of 105 attenders with 105 non-attenders) and did not find evidence of a statistically significant difference (p > 0.05).

In contrast, one study¹¹² – a prospective study of non-attendance in a physiotherapy outpatient department in Ireland – reported a statistically significant association between time of day of the appointment and did-not-attend rate. This study categorised attendance into three time periods – morning, early afternoon and late afternoon – in contrast to the studies above that simply used ‘morning compared with afternoon’. Late afternoon appointments produced a non-attendance rate of 6%, compared with 10% and 13% in the morning and early afternoon, respectively. A study¹²⁶ in the USA reported that morning appointments were significantly more likely to be kept (72.1%) than afternoon appointments (65.8%).

It may be that the cruder classification employed by the first three studies reported above – grouping early and later afternoon appointments – failed to identify time of day that is associated with higher attendance. If the main obstacle to attendance is conflicting work commitments, then it would seem likely that late afternoon (or evening, if offered) appointments would be more likely to be attended.

Day of the week

The available studies identified in our review produced equivocal evidence regarding the link between day of the week and appointment attendance. One UK study based in a specialist alcohol treatment centre reported no evidence of a relationship between day of appointment and attendance. Authors undertook multivariate analysis of patient characteristics of non-repliers (n = 100), non-attenders (n = 100) and attenders (n = 100) and found day of appointment (Monday to Thursday; clinics did not run on Friday) did not have any significant bearing on patient attendance in response to referrals.⁸⁹ Similarly, a study¹²⁶ in the USA reported no association between attendance level at a family practice residency clinic and day of the week (65.8%).

However, three studies (two RCTs^63,85 and a case–control analysis¹²¹) reported a statistically significant association between day of appointment and attendance rates, but the findings were inconsistent in terms of which days produced the best level of attendance.

A RCT in Portugal⁶³ included 3899 patients of various ages across various outpatient clinics and found that looking at the overall attendance data (for reminder and control groups) patients were more likely to not attend in the middle of the week (Wednesday). In fact, the non-attendance rate increased from Monday to Wednesday and decreased from Wednesday to Friday. The authors suggest that this pattern can be explained by the fact that people going to appointments on Monday or Friday can skip their jobs and have an extended weekend.

A UK study¹²¹ exploring attendance behaviour at a gynaecology clinic, with an ethnically diverse and deprived patient population, employed a prospective case–control design to explore the association of day of appointment with attendance (105 attenders compared with 105 non-attenders). In contrast to the Portuguese study, the non-attendance rate was significantly higher on Mondays and Fridays than on other days (non-attendance rates on Monday and Friday were 17.6% compared with 15.1% on the other three days; p = 0.009).

Similarly, a RCT⁸⁵ involving 679 patients invited for an appointment at two physical therapy outpatient departments in metropolitan acute public hospitals in Australia found higher non-attendance on Mondays and Fridays. The non-attendance rate on Mondays was 16% and on Fridays was 24%, compared with 10–13% on other days of the week. They also found that younger patients were more likely to not attend and speculated that this may be to do with difficulty attending during normal working hours.

Subsequently, a large-scale UK data analysis has produced some noteworthy results. Ellis and Jenkins¹²⁷ conducted two related studies. In the first they examined attendance records for 4,538,294 outpatient hospital appointments across Scotland between 1 January 2008 and 31 December 2010. The did-not-attend rate was highest on Mondays (11%), lowest on Fridays (9.7%) and decreased monotonically over the week. In their second study, they analysed attendance records for 10,895 appointments at a single GP clinic in Glasgow, Scotland. Here again, did-not-attend rate was highest on Mondays (6.2%), lowest on Fridays (4.2%) and decreased monotonically over the week. A further observation was that this weekly decline was found in male and female patient groups of all ages, but was steeper for younger age groups. They conclude that the did-not-attend rate could be significantly reduced by preferentially loading appointments onto high-attendance days.

In addition to these studies that employed quantitative analyses to compare attenders and non-attenders, several descriptive qualitative and quantitative studies report, perhaps not surprisingly, the importance of appointments being compatible with other commitments. Again, employment commitments featured prominently.

A qualitative study in the UK¹¹⁵ exploring attendance behaviour among asthma patients reported that the inability to schedule appointments at a convenient time was considered a barrier to attendance. In another UK study,¹²⁸ the authors reported that they had previously shown that 63% of patients attending the cardiorespiratory outpatient clinics would like out-of-hours clinics, largely because they are in employment during the day. A discrete choice experiment among 1200 patients presented respondents with trade-offs between two hypothetical, yet realistic, health conditions: an acute, low-worry condition and an ongoing, high-worry condition. For both conditions, one of the four valued components of appointment systems was a convenient time of day.

Explanations and implications for reminders

Higher levels of non-attendance at particular times and on particular days may primarily be explained by incompatibility with other commitments, particularly employment.

Several qualitative and descriptive quantitative studies identify incompatibility with other commitments as a reason for non-attendance. For example, in a qualitative study investigating the perspectives of young adults attending diabetes outpatient clinics in the UK,¹⁰¹ some respondents reported that the available hours at the clinic were not compatible with unsympathetic employers’ demands and that time booked off work for an appointment could sometimes be cancelled at very short notice. Addressing this aspect of non-attendance would clearly require attention to the appointment systems and clinic opening hours, rather than to reminder interventions.¹⁰¹

Addressing this aspect of non-attendance would clearly require attention to the appointment systems and clinic opening hours, rather than to reminder interventions.

However, available evidence suggests that the proportion of patients who actually miss appointments because they are unable to secure appointment times that are convenient varies considerably between settings. For example, in a UK study¹²⁹ based in a genitourinary clinic, no patients reported that clinic opening hours prevented their attendance. Wilkinson and Daly¹³⁰ report a small retrospective and prospective audit of 142 patients who did not attend their appointment at Care Plus and diabetes clinics in a large general practice in New Zealand, finding that work commitments or being unable to take time off work were cited by only four participants (although they identified the patient population as being predominantly > 65 years and highly deprived; therefore, potentially high numbers were unemployed). A descriptive US study of pregnant women (from a deprived and ethnically diverse patient population) found that 12% of no-show patients who were surveyed said that their reason for non-attendance was that their appointment was at an inconvenient day or time. Casey et al.¹³¹ conducted a small (n = 76) telephone survey over a 1-month time frame to determine reasons for non-attendance in patients who had missed their urology outpatient appointment and found that approximately 10% were unable to attend because of work commitments.

Thus, although it seems reasonable to assume that having an appointment time that is compatible with other commitments is important for all patients (albeit that some patients will consider that they have more competing commitments than others), available evidence does not suggest that large proportions of patients in different settings are unable to ensure such compatibility when the original appointment is made. The extent to which this is an important contributory factor to non-attendance will clearly relate to the appointment system and patient involvement in identifying the timing of the initial appointment (see Time to wait to the appointment).

Furthermore, incompatibility of appointment timing will translate into consistent patterns of higher non-attendance at certain times of day or on certain days of the week only if a significant proportion of people have commitments that are hard to shift on those particular times/days and are nevertheless offered appointments at those times. Again, it seems likely that this will be a more significant issue when appointments are allocated rather than booked in conjunction with the patient. It is also likely that any such patterns would be context specific, as daily and weekly work patterns vary between settings, thus reducing the transferability of findings across settings and highlighting that clinic managers and practitioners need to be aware of local schedules.

Aside from incompatibility issues, some studies have suggested that at least part of the explanation for higher non-attendance on certain days may be greater forgetfulness. For instance, a UK study¹²¹ exploring attendance behaviour at a gynaecology clinic found that a majority of patients cited ‘forgetting’ and family and work commitments as reasons for FTA and the authors postulated that patients are more likely to default on days falling after and before the weekend, as their daily routine is less regular. The authors also reported that these reasons might also be partly explained by the fact that the defaulters are, on average, 8 years younger than those who are compliant (38.93 vs. 46.44 years; p = 0.002) and, thus, may have school-aged children.

If people do indeed forget their appointments more when they coincide with certain days, then clearly reminders would be particularly important for patients with appointments on those days.

Explanations and implications for reminders

Several papers identified through the review provided some insight into the reasons why a longer delay to appointment is associated with lower attendance.

First, unsurprisingly, forgetfulness is implicated as the cause of the association in several studies. For instance, in a study of adolescent outpatients in Switzerland,¹³⁵ the authors reported that forgetting the appointment was a common cause and suggested that the higher non-attendance for appointments with a long delay probably reflects the greater risk of forgetting the appointment. Similarly, a study in a dermatology clinic in Italy¹³⁶ concluded that as long delays to appointments were common; this explains why the most frequent reason given for non-attendance is forgetting the appointment.

However, other factors are also identified as potentially contributing to lower attendance when appointments are scheduled further in advance. First, it has been suggested that other issues are more likely to arise that mean the appointment timing becomes incompatible.¹³⁵

It has also been suggested that when appointments are scheduled a long time in advance, patient symptoms may be resolved, either because they resolve themselves or because the patient (or referring health-care professional) opts to seek alternative care. For instance, an Irish study that examined appointments in a general surgical outpatients department²⁰ revealed that resolution of symptoms accounted for almost one-third of missed appointments. The authors suggested that this finding questions the appropriateness of some referrals and suggests that many patients might be managed in the primary care setting. They suggest that in the absence of a quick referral, GPs may be forced to institute treatment measures as intermediate solutions and that these may often these prove sufficient to alleviate symptoms. In the Italian study,¹³⁶ the authors also reported that a common reason for non-attendance was that the patient had been able to consult a private dermatologist in a shorter time.

However, some authors suggested that under particular circumstances, a long delay could result in reduced motivation on the part of the patient despite continued need. In the context of an eating disorders clinic, Bell and Newns¹³² noted that their clients ‘. . . may be at a motivational juncture and delaying their appointment on a treatment programme may mean that by the time their appointment is due, they are less ready to address change . . . All patients waiting for mental health care are potentially at risk of failing to engage’. Similarly, this association, also found in a study by Booth and Bennett⁸⁹ in a specialist alcohol treatment centre in the UK, seems unlikely to be explained by patient symptoms/need having been resolved and more likely by a loss of motivation, which raises concerns about long appointment waits contributing to poor health. It may be that scheduling an appointment a long time in advance can convey the impression to the patient that the appointment is unimportant.

One study suggested an alternative explanation for the association between time to appointment and non-attendance. The authors of a study in a US veteran’s clinic¹³⁴ speculated ‘it is known that clinicians vary widely in their selection of return visit interval, it is possible that characteristics of clinicians who choose shorter intervals affect these rates [of non-attendance and cancellation] rather than the interval itself’. However, the consistency of this relationship across contexts suggests that this mechanism, even if present, is unlikely to explain the observed patterns in their entirety.

It seems likely that the association between time to appointment and attendance rates will also depend on the nature of the appointment, in particular whether it is a one-off (or first) appointment or rather a regular (repeat) appointment that is scheduled at regular (familiar) intervals of some considerable duration. However, the available evidence did not provide any such exploration.

Keeping waiting times down remains a government priority with patient rights to receive non-emergency treatment within a maximum waiting time being enshrined in the NHS constitution.¹³⁷ A short waiting time is also shown to be an important criterion for patients seeking care in many contexts. For instance, a discrete choice experiment¹²⁸ among 1200 patients in which respondents were presented with making trade-offs between different levels of attributes for two hypothetical, yet realistic, health conditions: an acute, low-worry and an on-going, high-worry condition found that for both conditions one of the four key components of appointment systems that were of value was an appointment sooner rather than later (fourth out of four – behind choice of doctor, a convenient time of day and a doctor rather than a nurse).

Nevertheless, some appointments will necessarily be scheduled at longer intervals than others either because of constraints in appointment slots or because the patient’s treatment demands such an interval. The available evidence suggests some issues for consideration in relation to reminder systems:

• Reminders will be particularly important when appointments are scheduled well in advance.
• It may be useful to explain to patients why they are having to wait and why the appointment is, nevertheless, important.
• It is particularly important to provide easy ways to cancel when appointments are scheduled long in advance given that a proportion of patients will no longer need the appointment or no longer be able to attend.
• Keeping waiting times to a minimum is important (as already recognised) in clinics that deal with patients with serious conditions that are unlikely to resolve themselves, particularly mental health conditions that result in the patient’s readiness to engage with services fluctuating over time.

Explanations and implications for reminder/attendance interventions

Better attendance rates when patients are engaged in initiating and scheduling their own appointment may reflect numerous different mechanisms. First, and perhaps most obviously, the timing is more likely to be convenient for the patient. Second, patients may be less likely to forget if they have made the booking themselves (and perhaps entered a note of it into a diary at the same time). Third, patients may be more likely to feel obliged to attend if they have booked it themselves (and may, therefore, take steps to overcome obstacles to attendance that arise, etc.). There is some evidence that asking patients to enter into an agreement by sending back a confirmation of attendance or contracting to attend may act to compel patients to attend their appointment.^56,140,141 A more recent study¹⁴² adopted three specific mechanisms aimed at increasing attendance at primary care appointments, two of which can been seen to relate to engaging the patient more closely in the scheduling process with a view to reducing the likelihood of forgetting and increasing the feeling of obligation to attend: patients calling for an appointment were asked to repeat back the time and date of their appointment before the call ended and when booking follow-up appointments; patients were asked to write down the time and date on an appointment reminder card rather than health-care or reception staff doing it for them.

If patient involvement in appointment booking has an effect on causal pathways that a reminder intervention is also intended to address (e.g. prompting a forgetful patient, appealing to moral obligation) then, ceteris paribus, we would expect to find the baseline level of attendance to be higher and the reminder effect size to be lower in contexts in which patients are engaged in original booking than when they are not (because there would be fewer patients within the patient population who experienced the obstacle to attendance that the reminder seeks to overcome). The UK-based study by Milne et al.¹⁰⁸ did indeed find a smaller absolute reduction in non-attendance, from 5.2% to 3.8% (i.e. a difference of 1.4%) among those who experienced partial booking, than among those who did not, for whom non-attendance fell from 15.3% to 9.8% (i.e. a difference of 5.5%).

A shortcoming of some of the studies of the effectiveness of reminder interventions is that the pre-existing appointment system into which the reminder intervention is introduced is not always adequately described nor taken into consideration as a factor that might influence the effectiveness of the reminder in the current or other contexts.

Greater involvement of patients in the scheduling of their appointments appears to be beneficial in increasing attendance rates. However, it is worth noting a recent evaluation¹⁴¹ of the UK ‘Choose and Book’ initiative aiming to involve patients in the scheduling of their hospital care has reported that patients did not, in practice, experience the degree of choice over date, time and location that Choose and Book was designed to deliver.

If appointments are necessarily service initiated rather than patient initiated, efforts will often be needed to increase patient perception that attendance at the appointment will positively contribute to their health/well-being and will not imply any significant risks, downsides or inconvenience. Reminder systems in relation to such appointments will likely also need to address these issues rather than simply serve as a prompt for the date and time of the appointment.

Explanations and implications for reminders

Clearly, the results of studies comparing first and follow-up appointment attendance are equivocal. It seems likely that more sophisticated study designs are needed to fully understand the processes that are in operation. Indeed, explanations for the results presented have largely been speculative in studies reported to date.

Foley and O’Neill,⁹⁸ in their study of a UK dental clinic, reported that there was a significant cohort of patients who attend as casual patients with dental pain or facial swelling and who, having received symptomatic relief of their symptoms, do not attend for further appointments that are often booked with the non-specialist dentists. Similarly, in their study of antenatal care among a deprived US population, Maxwell et al.⁷⁴ speculate that higher no-show rates for follow-up visits relate to the ‘crisis-oriented health care-seeking behaviours’ of the patient population and the fact it is often the patient who identifies the need for an initial visit, while the provider often identifies the need for follow-up care. Therefore, follow-up visits may not be as highly valued by the patient.

In contrast, Roberts et al.⁸² suggest that higher attendance among established patients compared with new patients is explained by established patients feeling a connection with their provider and, therefore, being more likely to attend the appointment to maintain the relationship and continuity of care. Similarly, in their study of physiotherapy in New Zealand, Taylor et al.⁸⁵ speculate that higher attendance for review appointments may be because of ‘developing an understanding of benefits of attending and establishment of a relationship with the treating therapist’.

The above findings suggest that reminder interventions are appropriate for both first and follow-up appointments, but that the distribution of reasons for non-attendance among those who do not attend may differ between these two scenarios as well as across service contexts and may therefore warrant different types of reminder input.

Explanations and implications for reminder/attendance interventions

The variable findings across different studies examining the association between travel distance/accessibility and attendance highlight several complexities and considerations.

First, varied measurement approaches between studies can compromise their comparability; for instance, while some studies use travel time, others use travel distance. Furthermore, the qualitative studies indicate that clinic accessibility is composed of multiple components not simply being a function of distance or travel time. Potentially, these include travel costs, ease/difficulty of parking and public transport availability on the route. It is possible that such dimensions vary between patients who are grouped according to travel distance or travel time and also between clinic contexts that appear to have similar patient profiles in terms of travel times/distances. For example, the ability to park near to the facility may be more of an issue for parents bringing small children to an appointment than for young adults, who may be more likely to travel by public transport. These factors do not seem to have been tested rigorously in the current research base.

Second, it seems likely that transport issues (however measured) are more significant for some groups of patients than for others. The literature suggests that patients who are more socioeconomically deprived may experience transport-related obstacles to attendance more often than more advantaged patient populations, for instance because travel costs are more prohibitive or because they are more reliant on public transport (see Deprivation). Transport issues may also be more relevant to patients with young children and the elderly.

Third, Swarbrick et al.¹²⁹ suggest that more readily accessible clinics can actually encourage non-attendance, noting of non-attenders that ‘such patients appear capable of accessing GUM clinic services without difficulty, and may be prepared to miss appointments precisely because alternative access (whether through new appointments, or via “walk-in” services) is known to be equally accessible’. This suggestion alerts us to the fact that travel distances/durations and other aspects of physical accessibility may also inter-relate with appointment availability and booking systems, as well as patient motivations, to influence attendance behaviour.

It seems clear that further research is needed to fully understand the relationships between clinic location/transport issues and appointment attendance, but in relation to reminder/attendance interventions, the following implications can be drawn from the existing evidence base.

• Services should consider whether or not they can include within any reminder useful information that could aid patients’ journey to their appointment.
• Different groups of patients will experience the same journey differently.
• For some groups of patients in some settings, reminders will be insufficient to prompt attendance because transport difficulties over-ride the incentives to attend.

Explanations and implications for reminders

Several mechanisms are suggested for differences in attendance behaviour by type of provider to be seen. Differential attendance may relate to patient perceptions of the importance of attending the appointment and/or to the quality of care they expect to be received.

A study¹²⁸ using a discrete choice experiment among 1200 patients in which respondents were presented with trade-offs between two hypothetical, yet realistic, health conditions – an acute, low-worry condition and an on-going, high-worry condition – found that, for both conditions, the two of the four key components of appointment systems that were of value were being offered a choice of doctor and a doctor rather than a nurse.

Magnes⁹⁷ suggested that factors such as continuity of care, perceived clinical competence and the provision of non-medical interventions might have an impact on attendance rates.

Chariatte et al.¹³⁵ observed that the risk of missing an appointment was also increased among those who had consulted a paramedical provider at the last appointment, suggesting that expectations for a subsequent appointment may well be shaped and modified by past experience. However, differential allocation of more serious cases to higher-grade staff could also affect the rates of attendance. This could be because less serious cases may resolve themselves before the appointment or patients with less serious cases may be more likely to forget their appointment or to prioritise other commitments over appointment attendance. In a mental health context, there is specific concern that more serious cases are more likely to be those that do not attend.

French et al.¹¹² cite an earlier study by Brookes¹⁵³ that reported a perceived increase in the rate of non-attendance for the senior therapist as a result of such factors as leave and transfer of patients from other staff. However, these anecdotal reasons lacked detailed analysis. In this study, it was noted that one senior therapist who was specialised in one particular area with a complex group of patients had a did-not-attend rate of 45%.

It is unclear what implications can be drawn from these findings in terms of reminder systems. It could be argued that reminders should not indicate which health-care professional will be seen; for instance, the practice in some clinics is always make the appointment under the name of the senior provider, even if the practitioner to be seen will be another member of staff. However, this could potentially be counterproductive for those patients who have established a positive relationship with a practitioner whom they would like to see again.

More generally, it would seem important to monitor attendance patterns by individual members of staff as well as grades of staff in order to identify any patterns indicative of issues to be addressed, such as poorer engagement/alliance achieved by particular staff, while recognising that attendance levels will be influenced by such factors as the types of cases referred to different providers within a team.

Explanations and implications for reminders

Numerous explanations have been advanced for the positive association between patient age and attendance. First, it is postulated that older people may have fewer competing commitments than younger people⁷⁷ and that children in particular may have high rates of non-show because of their dependence on other people (usually working-age adults) to accompany them to an appointment.⁶³ No studies were identified that explored the age group of parents/carers in relation to children’s attendance at appointments.

A second line of argument, however, is that older patients may be more likely to attend scheduled appointments because of the nature of their health condition and being more likely than younger patients to have multiple conditions necessitating appointment attendance⁷⁷ or less likely to have symptoms that resolve themselves before the appointment date.⁸⁹ Parikh et al.⁷⁷ also speculated that older patients may be more cognisant of their own health care.

To date, there has been little detailed exploration of these alternative potential explanations. Nevertheless, as discussed in Chapter 4, Evidence statement (F.1): there is sufficient weak equivocal evidence to suggest that age does not have a differential effect, over and above pre-existing appointment behaviour, on reminder effectiveness (in terms of attendance, cancellations or rebooking) (evidence category IVa), there is good evidence that reminders are effective at improving attendance among all age groups. Furthermore, although rates of non-attendance are higher among younger patients, it is older patients who make up the majority of appointments, often at outpatient clinics where non-attendance costs the UK NHS an estimated £790M per year.¹⁶⁵ Therefore, the findings reported provide no support for the suggestion that the use of reminder systems should be restricted to certain patient age groups. Furthermore, the findings here confirm the importance of reminder systems enabling patients to cancel and, if necessary, rebook their appointment with ease. However, as discussed above, there are important considerations to be made in relation to the type of reminder technology that may be most appropriate for different age groups (e.g. mobile phones remain less commonly used by older populations¹⁰⁸).

Explanations and implications for reminders

Given that the reasons behind any observed gender differential in attendance behaviour are likely to be shaped by gender-related factors, it is unsurprising that contrasting results are reported across geographical and cultural contexts. In general, however, the available studies that reported on attendance patterns did not explore in any detail the reasons behind any observed gender differentials.

Instead, authors have speculated about the underlying causes of observed gender differences in attendance. For example, when it was found that females were less likely to attend a dental appointment than males, Can et al.⁵⁶ suggested ‘. . . that dentists may be more willing to refer a girl when the malocclusion is mild and following the referral the patients then change their mind about attending. This, however, is purely conjecture.’.

Some authors have suggested that differentials could arise because of different patterns of disease and symptomology between male and female patients. For example, Hon et al.¹²² were unable identify the exact reasons for higher non-attendance among male patients in their paediatric dermatology clinic in Hong Kong, but speculated that female referrals may involve more serious dermatological conditions. However, as noted above (see Sex), it is also recognised that differential patterns of referral for male and female patients, as well as differential responses by patients (and their carers/parents in the case of children), could also contribute to the patterns of attendance observed.

In relation to reminders, the available evidence on attendance rates does not suggest that reminder systems should be differentially employed for male and female patients, but clearly this is an area that warrants further investigation.

Explanations and implications for reminders

A range of explanations have been advanced for why non-attendance is often higher among the more deprived sections of patient populations, as well as at clinic level for those clinics serving deprived areas. However, there has been little detailed exploration of these causal pathways in the literature that has focused on appointment attendance behaviour.

Several authors draw attention to the potential influence of structural factors, such as poor transport options,^{89,123,148,166} low ownership of landline telephones,⁸⁹ low levels of social support and difficulties in arranging child care.⁸⁶ A systematic review by George and Rubin¹⁸ identifies that the appointment systems themselves can prove a barrier to care. They may be particularly challenging to use for members of communities in areas of social deprivation, because such systems require resources and competences that are not readily available. People in these groups may have less predictable, chaotic lives that are not consistent with structured systems. They conclude that non-attendance can be viewed as the manifestation of a critical level of unsuitability in the agreed arrangements for an access episode. This perspective that problematises the rigid system rather than a perceived ‘difficult’ population is to be welcomed.¹⁶⁸ As Dixon-Woods et al.¹⁶⁸ point out, services that use appointments systems rely on people being able to read and require people to present themselves in particular places at particular times. Such services include immunisation and screening programmes, outpatient clinics and elective procedures, and these encounter very high rates of ‘default’ by more deprived people.

Higher levels of non-attendance may also in part be explained by the mobility of people in deprived populations. People who are in rented accommodation rather than owner occupation may change address much more frequently, and this puts them at risk of not receiving invitations (or reminders).^103,168 The Fourth National Survey of Morbidity in General Practice¹⁷⁰ found that 8% of people registered with practices were not at their stated addresses and were not contactable. At the more extreme end, people who are homeless or who live in travelling communities may not be sent or receive invitations to appointments at all¹⁷¹ while asylum seekers may face similar obstacles to receiving appointments and navigating the health-care system, resulting in high levels of non-attendance.⁷⁸

Heath¹⁷² argues that all barriers to consultation should be examined to ensure that those on low incomes are not disadvantaged, giving the highly pertinent example of those without a telephone, who may be easily disadvantaged if appointment systems are rigidly enforced and largely organised by telephone, or if there is increased use of e-mail. Another concern regarding text messaging reminders is their possible impact on health inequalities, as people in higher socioeconomic groups, who are more likely to own a mobile phone, will be less likely to miss appointments.¹⁷³ However, this concern may not be realised given mobile phone ownership statistics and other unpublished studies regarding mobile phone use and socioeconomic status.^174,175 The availability of same-day compared with advance appointments and the potential for such appointment mixes to affect different groups of patients differentially has also been raised.^176–178 It has been suggested that patients in deprived areas are more likely to use same-day appointments.¹⁷⁷ A recent study found that patients receiving same-day care were likely to be in work and have a higher educational status.¹⁷⁶ Sampson¹⁷⁷ found differential levels of satisfaction with appointment mixes by age and by deprivation of practice population and concluded that it is important to accommodate the requirements of different patient groups by allowing both pre-bookable and same-day appointments; Sampson’s conclusions echo those of earlier studies.^176,178

A further line of explanation for lower levels of attendance among deprived patient groups relates closely to the issues of patient–provider communication, therapeutic alliance and engagement discussed in section Patient–provider ‘alliance’, communication and ‘engagement’. One study¹⁰³ has suggested the possibility that deprived groups are more likely than the better-off to hold a negative perception of health services on offer. Hussain-Gambles et al.¹⁰⁴ report on the attitudes of health-care providers who perceived patients living in more deprived areas as lacking responsibility and missing more appointments, and suggests that these negative attitudes may not be beneficial to improving attendance. Patel et al.¹⁶⁴ suggest that single parents and low-wage earners find dental treatment a low priority.

Associations between employment status and appointment attendance are also important to consider, since the most common reasons cited for missing an appointment, after forgetting it, are family and work commitments. However, the findings across studies are inconsistent and difficult to interpret because of the complex of causal pathways that may be in operation. First, as discussed above under Reported reasons for non-attendance, incompatibility of appointment timing with work commitments is commonly cited as a reason for appointment non-attendance. For instance, Roberts and Partridge¹⁷⁹ had previously shown that 63% of patients attending their cardiorespiratory outpatient clinics would like out-of-hours clinics, largely because they are in employment during the day. However, the degree to which employment status presents a barrier to appointment attendance is likely to depend on both the type of employment and the appointment system on offer. It is suggested that people in lower occupational groups may have less flexibility at work and, therefore, face greater problems in negotiating time off work for health-care appointment attendance.¹⁶⁸ However, people who are unemployed have been found in some cases to have higher rates of non-attendance than those who are employed (see, for instance, Patel et al.¹⁶⁴) and they may face a different set of obstacles to appointment attendance that are linked to lack of income and structural factors.

The available literature tends to suggest that deprived populations face multiple obstacles to health-care appointment attendance. Thus, while simple reminders may be effective at prompting attendance among those who are at risk of forgetting their appointment, it seems likely that more sophisticated attendance interventions will be needed to achieve high levels of attendance. Clinics that achieve high levels of attendance despite serving patient populations with high levels of socioeconomic deprivation would warrant close investigation, as they may have introduced ways of working that could be transferable to other settings. Furthermore, as discussed above, reminder systems are very dependent on accurate and stable data from patients and so deprived populations with unstable contact details (either address or telephones) may mean these patients are disadvantaged.¹⁰³

Explanations and implications for reminders

Ethnic (and racial) categories are proxy markers for a host of inter-related factors that may affect attendance behaviours. In particular, the interplay of minority ethnic status and socioeconomic deprivation requires careful consideration. However, studies of attendance behaviour have largely failed to unpack ethnicity to examine causal pathways in any detail. Nevertheless, various potential explanations for lower levels of attendance among minority ethnic (or racial) groups have been suggested.

First, several studies identify language difficulties as contributing to lower attendance among some minority ethnic patients. For example, Maxwell et al.⁷⁴ found, in a US multiethnic population, that reasons for non-attendance included a lack of understanding of the purpose of the appointment related to language difficulties. Similarly, a study in inner London¹⁴⁸ suggested that language difficulties may result in problems in accessing available facilitators for attendance, specifically hospital transport. It is worth noting that one study reported no differences in attendance levels by language competency and has drawn attention to the fact that availability of translator services and advocacy for immigrant communities can help to ensure that there is no disparity in the delivery of services in this respect.¹²¹

Second, higher levels of mistrust and lower degrees of therapeutic alliance or engagement with services have been noted for minority ethnic patients across several studies (see, for example, Mir and Sheikh¹⁸⁵).

Third, as minority ethnic populations often experience high levels of individual and neighbourhood deprivation, the structural factors identified above – such as transport difficulties, high levels of residential mobility and low access to telephones – frequently apply to these groups of patients. Interestingly, however, US observers have remarked that cellular phones are the first technology with a documented trend towards more use by other ethnicities than Caucasians. African Americans and English-speaking Latinos were identified among the most active users of cell phones.^186,187 According to the Pew Report,¹⁸⁶ more African Americans and Latinos than Caucasians own a cell phone (87% vs. 80%) and minority cell phone owners use a greater range of the features on their phones. Denizard-Thompson et al.¹⁸⁷ found, in their study of low-income patients in an adult medicine clinic, that SMS messaging was more common among African Americans than Caucasians, and was more common among females and patients aged < 50 years. Although we must be cautious in translating such trends to a UK population, it is important to consider that the overall effect of mobile phone access may be to ‘leapfrog’ other technologies such as landlines, thereby widening access to services. Clearly, wireless mobile technology holds significant potential to improve communication regarding appointments and reminders and increase utilisation in certain underserved populations provided that patients have a mobile phone, can afford a mobile tariff and are able to utilise the full range of features available on their mobile phone. However, caution should be exhibited in recognition that Denizard-Thompson et al.¹⁸⁷ observe that clinicians typically overestimated the usage of mobile phone technologies by their population.

Fourth, some studies have recognised that cultural factors may influence attendance behaviour for particular groups of patients in particular contexts. For example, in the study by Gatrad,¹⁸¹ various cultural practices found among the local Asian Muslim population were identified as potentially affecting attendance patterns and, therefore, requiring accommodation within the appointment-making system, such as lunchtime Friday prayers.

Explanations and implications for reminders

Although low levels of attendance among patients experiencing the above health and well-being-related characteristics, i.e. substance misuse, poor mental or physical health, and/or low levels of social support, may in part be explained by forgetfulness, it seems likely that other factors are also in operation that are unlikely to be overcome by simple reminder systems.

These characteristics are likely to be clustered within particular clinic populations, particularly clinics serving those with mental illnesses and elderly populations. Such clinics will need to consider more sophisticated interventions to support attendance. In addition, however, within any clinic setting, managers should be alert to the fact that patients exhibiting these characteristics may be particularly vulnerable to non-attendance and that simple reminder systems may further disadvantage them when compared with the general patient population.

Explanations and implications for reminders

When patients do not recognise the need to attend an appointment, or see little value/benefit in attending, simple reminders are unlikely to encourage attendance, although they could be useful in encouraging people to cancel. Non-attendance in this context could be seen as a positive sign of resolution of symptoms without clinical intervention, a marker of inappropriate referral as judged by the patient or a warning sign of unacceptable delays in receiving an appointment. Clearly, when attendance is important, even for those who are asymptomatic or experiencing only minor symptoms, attendance interventions will need to enhance patients’ perception that attendance at the appointment will contribute positively to their health and well-being. There are, for example, studies focused on screening appointments that have evaluated the impact of different approaches to increasing patient perception of the importance of attendance that could provide useful insights for other health-care contexts for which low attendance is a problem, such as ‘stepped reminders’^46,195 and patient navigators.^196,197

Explanations and implications for reminders

Included studies were ambivalent with regard to whether or not previous non-attendance may predict future non-attendance. It seems largely intuitive that most people can find themselves in circumstances which mean that they may not be able to attend an appointment from time to time and that they may need to cancel an appointment;¹⁰¹ therefore, at a general level, it would seem sensible to send all patients a reminder which includes a message about cancelling an unwanted appointment and rescheduling for a future appointment if treatment is still required. For health services that do find that in their population there is a clear relationship between previous non-attendance and future non-attendance, and that there is a relatively high rate of ‘frequent defaulters’, more intensive reminder strategies such as the sequential reminder intervention described by Perron⁷⁸ could be initiated. First, a telephone call to either landline or mobile; second, a SMS if participants do not answer the telephone after three attempts and have a mobile phone and, finally, a postal reminder if participants did not answer the telephone, had no mobile phone for SMS, or had no phone at all. Such a design, although labour intensive, would reach the maximum number of participants and may increase attendance rates while still being cost-effective.