High or moderate evidence
(is there high or moderate quality evidence?)
The higher the quality of evidence, the more likely is a strong recommendation. | □ Yes
☒ No | ⊕○○○ | There is low- to very-low-quality evidence from both randomized and observational controlled studies for recurrence rates and adverse events. In general estimates of effect are obtained from single arm studies with no independent control. Outcomes, such as some fertility outcomes and acceptability were not measured. |
Certainty about the balance of benefits versus harms and burdens
(is there certainty?)
The larger the difference between the desirable and undesirable consequences and the certainty around that difference, the more likely a strong recommendation. The smaller the net benefit and the lower the certainty for that benefit, the more likely is a conditional/ weak recommendation. | ☒ Yes
□ No | There is considerable benefit and relatively little harm |
Recurrence rates of CIN from observational studies with no independent control show CIN II–III, 4% CIN I, 2% All CIN, 6%
Absolute risk reduction in cervical cancer with cryotherapy was calculated as 18% over 30 years for baseline risk of 1%; 9% over 30 years for 0.5% assumptions: from observational studies with no independent control the relative risk reduction with cryotherapy is 86%, but a spontaneous regression of 28% which gives the relative risk reduction with cryotherapy as 61% [86% − (28% × 86%)]. Using 1% baseline risk without cryotherapy, the absolute risk reduction with cryotherapy is 0.61% over 1 year or 18% over 30 years. Using 0.5% gives 0.3% over 1 year or 9% over 30 years.
Major adverse effects occurred rarely with cryotherapy, but minor may occur more frequently. It is unclear whether cryotherapy affects fertility/ obstetric outcomes, or whether cryotherapy is unacceptable to women. Risk of HIV shedding or acquisition is not known, but this risk is unlikely to outweigh the benefits.
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Certainty in or similar values
(is there certainty or similarity?)
The more certainty or similarity in values and preferences, the more likely a strong recommendation. | ☒ Yes
□ No | |
A high value was placed on avoiding CIN recurrence, avoiding serious adverse events and acceptability to the patient A low value was placed on minor adverse events
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Resource implications
The lower the cost of an intervention compared with the alternative, and other costs related to the decision – that is, the fewer resources consumed – the more likely is a strong recommendation. | ☒ Yes
□ No | Resources required for cryotherapy but they are generally affordable |
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| Overall strength of recommendation | Strong |
