• mental recall;
  • falls;
  • systematic review;
  • bias;
  • reproducibility of results

Objectives: To determine whether the interval over which patients are asked to remember their falls affects fall reporting.

Design: Systematic literature review.

Setting: Community.

Participants: Individuals being monitored for falls in prospective studies that asked participants to recall falls over varying intervals.

Measurements: Sensitivity and specificity of retrospective recall compared with a criterion-standard prospective assessment using some form of ongoing fall monitoring.

Results: Six studies met the inclusion criteria. Recall of falls in the previous year was specific (specificity 91–95%) but less sensitive (sensitivity 80–89%) than the criterion standard of ongoing prospective collection of fall data using fall calendars or postcards. Patients with injurious falls were more likely to recall their falls. Lower Mini-Mental State Examination score was associated with poorer recall of falls in the one study addressing this issue.

Conclusion: Whenever accurate data on all falls are critical, such as with interventions to decrease the rate of falls, researchers should gather information on falls every week or every month from study participants. The optimal method of fall monitoring—postcard, calendar, diary, telephone, or some combination of these—remains unknown.