Sampling for Patient Exit Interviews: Assessment of Methods Using Mathematical Derivation and Computer Simulations
通过数学推导和蒙特卡洛模拟，评估了患者离院访谈中不同抽样方法的操作效率和无偏性，提出选择下一位进入诊室的患者作为受访者是最优的无偏抽样方法。
OBJECTIVE: (1) To evaluate the operational efficiency of various sampling methods for patient exit interviews; (2) to discuss under what circumstances each method yields an unbiased sample; and (3) to propose a new, operationally efficient, and unbiased sampling method. STUDY DESIGN: Literature review, mathematical derivation, and Monte Carlo simulations. PRINCIPAL FINDINGS: Our simulations show that in patient exit interviews it is most operationally efficient if the interviewer, after completing an interview, selects the next patient exiting the clinical consultation. We demonstrate mathematically that this method yields a biased sample: patients who spend a longer time with the clinician are overrepresented. This bias can be removed by selecting the next patient who enters, rather than exits, the consultation room. We show that this sampling method is operationally more efficient than alternative methods (systematic and simple random sampling) in most primary health care settings. CONCLUSION: Under the assumption that the order in which patients enter the consultation room is unrelated to the length of time spent with the clinician and the interviewer, selecting the next patient entering the consultation room tends to be the operationally most efficient unbiased sampling method for patient exit interviews.