Methodological issues in the recruitment of primary care patients with depression

To compare two strategies of patient recruitment, waiting room (WR) screening and screening after physician referral (PR), for participation in a treatment-outcome study of minor depression and dysthymia in primary care. The influence of demographic factors on patients' refusal to participate in WR screening was also examined.

Of a convenience sample of 3,344 first stage patients, a total of 609 patients were evaluated in a semi-structured manner using a two-stage screening procedure from the mood module of the Primary Care Evaluation of Mental Disorders (PRIME-MD).

Male and older patients were more likely to refuse participation in screening than female and younger patients. Waiting room screens yielded a higher number of qualified patients compared to PR screens, but PR screens yielded a higher percentage of patients who qualified for further participation.

The recruitment of male and older primary care patients is complicated by their tendency to refuse participation in WR screening for a treatment-outcome study of milder depression. Although each recruitment strategy offers advantages and disadvantages, the simultaneous use of both is recommended to recruit the most patients in the least amount of time.