Objective: To compare the quality of data recorded in urinary diaries completed for 3 days compared with those completed for 7 days.
Methods: Men and women enrolled in a randomized study of a nurse-led intervention for urinary incontinence were eligible for the study. Participants completed either a 7-day diary or a 3-day diary at baseline and after 8 weeks of the trial intervention. Data quality was assessed by categorizing each day as complete or incomplete. Incomplete days were those with fewer than four entries and those with obvious discrepancies from the rest of the diary days. Data were compared by percentage differences with 95% confidence intervals (95% CI).
Results: Two hundred forty-eight patients completed the 3-day diary, and 40 patients competed the 7-day diary. The majority of the respondents were women. There were more completed 3-day diaries (90.7%) compared with 7-day diaries (50%) (difference 40.7%, 95% CI 28.8-52.6%). When compared with the first 3 days of the 7-day diary, the 3-day diary contained more complete data (90.7% versus 65%; difference 25.7%, 95% CI 14.6-36.9%). These differences were seen in all data types except nocturnal incontinence. There was no evidence of association between diary completion and demographic characteristics.
Conclusion: Our data demonstrated that the 7-day diary included less complete data than the 3-day diary, even in the first 3 days of the longer diary. This finding suggests elements of both diary "fatigue" and also diary "despair" may be acting. We would suggest that a 3-day diary is superior in terms of data quality.
Level of evidence: III.