Accurate sampling in general practice waiting room surveys: methodological issues.
OBJECTIVES: This is a pilot study to test the validity of using one research assistant to train and support reception staff at five clinics to obtain waiting room data in general practice surveys. DESIGN: A research assistant trained reception staff at five randomly chosen general practices to administer a survey to all eligible women over a two-week period. Practices were audited daily by their appointment books and where possible by billing records to check total numbers of eligible women to determine the denominator of the sample. SETTING: Five metropolitan general practices in one divisional area. PARTICIPANTS: Twenty-five receptionists distributed surveys to 1,298 women. MAIN OUTCOME MEASURES: Number of eligible women missed at each clinic. RESULTS: The number of potential subjects missed by the reception staff ranged from nil to 18% with the appointment book audit. A second audit using billing records at three clinics revealed inaccuracies of up to 50%. The ability to accurately capture eligible patients for waiting room surveys depends on good administrative systems within the practice and motivated staff. CONCLUSIONS: It is important for general practice researchers to consider and account for eligible participants who are missed from the denominator with a waiting room survey method. Valid sampling using this method can be achieved in certain practices, however this may limit the generalisability of the findings.