CRD summary

This review concluded that various numbers of medications were associated with negative health outcomes, but more research was required to determine the consequences associated with unnecessary drug use. The conclusions did not address the apparent efficacy of interventions to reduce polypharmacy. Due to limitations in the methodology and reporting of the review, the reliability of these results is unclear.

Authors' objectives

To review attempts to reduce polypharmacy in older adults and to assess adverse events associated with polypharmacy. The review also examined the epidemiology of polypharmacy (outside the scope of this abstract).

Searching

MEDLINE and International Pharmaceutical Abstracts were searched from 1986 to June 2007. Search terms were reported. References of identified studies and authors' files, book chapters and recent reviews were checked. Only studies reported in English were eligible for inclusion.

Study selection

It appeared that randomised controlled trials (RCTs) that described interventions to reduce polypharmacy in individuals aged over 65 years were eligible for inclusion in the review. Observational studies that reported on the epidemiology of polypharmacy, including the consequences of multiple medicine use, in people aged over 65 were also eligible for inclusion.

The study designs of the included studies were not always clear. Intervention studies assessed prescriber education, use of a medication grid and implementation of geriatric evaluation and management. Participants were elderly inpatients or outpatients. Outcomes reported were reduction in numbers of medications and specific classes of medications, reduction in in unnecessary drug use defined by the Medication Appropriateness Index (MAI) and reduction in number of doses per day. Definitions of polypharmacy varied in the included studies.

The authors stated neither how the papers were selected for the review nor how many reviewers performed the selection.

Assessment of study quality

The authors did not state that they assessed validity

Data extraction

The authors stated neither how the data were extracted for the review nor how many reviewers performed the data extraction.

Methods of synthesis

Studies were combined in a narrative synthesis, grouped by the question addressed and the type of outcome or intervention reported on. The synthesis was supported by a table that permitted examination of differences between studies.

Results of the review

Eighteen studies that assessed the consequences of polypharmacy were included, as were five studies of interventions to reduce polypharmacy (numbers of patients were not reported for most studies).

Consequences of polypharmacy (18 studies): Reduced adherence, inappropriate prescribing, adverse drug reactions, increased incidence of geriatric syndromes, decline in physical and instrumental activities of daily living were detailed.

Interventions to reduce polypharmacy (five RCTs): Three studies assessed the impact of prescriber education on reducing polypharmacy. All studies reported reductions in medication use among patients involved in the studies. In one study, 12.5% of potentially inappropriate medications were stopped. In another, 20% of the 42% of patients who had a review had a medication stopped. In the third study the polypharmacy event rate (five or more medications) dropped from 7.99 to 4.1 per 1,000 patients. Statistical significance of these reductions was not reported.

One study assessed use of a medication grid by hospital residents and found that the number of medications taken by patients in the intervention group reduced by 0.92 per patient compared with an increase of 1.65 for the control group. This difference was statistically significant (p<0.001). There was also a reduction in the number of doses per day, although it was not clear whether this was statistically significant.

The use of inpatient geriatric evaluation and management was found by one RCT (n=834) to result in a statistically significant reduction in unnecessary drug use (defined by the MAI) compared with usual care (p < 0.05).

Cost information

Older patients with heart failure who took 11 drug doses per day had annual drug costs above US$3,800 in 2001.

Authors' conclusions

Many studies had found that various numbers of medications were associated with negative health outcomes, but more research was required to determine the consequences associated with unnecessary drug use.

CRD commentary

The review questions and the inclusion criteria were clear but very broad. The authors searched only two databases and restricted the review to studies reported in English; these factors may have increased the chances that relevant studies were not included in the review and of language bias occurring. The authors did not report using methods designed to reduce reviewer bias and error at any stage of the review process. They did not report assessing the validity of included studies, which meant that it was difficult to determine the reliability of the data on which the conclusions were based. This difficulty increased because there was only limited reporting of study details; study size and design could not be determined in most cases. The decision to adopt a narrative synthesis appeared appropriate given the clinical and methodological differences between the studies. The authors' conclusions reflected the results of the review, although they did not address the apparent efficacy of interventions to reduce polypharmacy. The limited search, lack of a validity assessment and poor reporting of the review meant that it was difficult to determine the reliability of the results of the review.

Implications of the review for practice and research

Practice: The authors stated that health care professionals should be aware of the risks associated with polypharmacy and fully evaluate all medications at each patient visit to prevent polypharmacy from occurring.

Research: The authors stated that further research was required to determine the consequences associated with unnecessary drug use.

Funding

Not stated.

Bibliographic details

Hajjar ER, Cafiero AC, Hanlon JT. Polypharmacy in elderly patients. American Journal of Geriatric Pharmacotherapy 2007; 5(4): 345-351. [PubMed: 18179993]

Original Paper URL

http://dx.doi.org/doi:10.1016/j.amjopharm.2007.12.002

Indexing Status

Subject indexing assigned by NLM

MeSH

Age Factors; Aged; Drug Toxicity /epidemiology /etiology; Humans; Medication Errors /prevention & control /statistics & numerical data; Physician's Practice Patterns /standards /statistics & numerical data; Polypharmacy; Randomized Controlled Trials as Topic; Risk Factors

AccessionNumber

12008102986

Database entry date

02/12/2009

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.