Microalbuminuria screening for patients having type 2 diabetes mellitus: who wants to participate?

BACKGROUND AND OBJECTIVES "Difficult-to-recruit" patients are sometimes less compliant with their care, are more reluctant to seek medical attention and less likely to survive than their "easy-to-recruit" counterparts. They also tend to be excluded from clinical trials. The aim of this paper was to evaluate whether such differences extend to patients' willingness to be screened for diabetic nephropathy in a family practice setting. DESIGN A cross-sectional study. SETTING A Canadian university family practice unit. PATIENTS Two hundred and forty-seven patients with type 2 (adult-onset) diabetes mellitus as identified by computer searches of patient records of approximately 12,000 patients in the family practice unit. INTERVENTION A cross-sectional secondary preventive screening program obtained urine samples from all patients with type 2 diabetes mellitus, regardless of patients' willingness to participate. MAIN OUTCOME MEASURE The prevalence of micro- and macroalbuminuria. RESULTS Of the 247 patients identified, 186 (75%) easy-to-recruit enrollees agreed to participate in screening and 61 (25%) difficult-to-recruit non-enrollees initially declined to be screened. The non-enrollees were subsequently evaluated by their own family physicians as part of routine clinical care and the results were captured for analysis. Overall rates of albuminuria were similar in the easy- and difficult-to-recruit groups (31% versus 38%, p = 0.151). The main predictors of albuminuria were female sex (odds ratio [OR] = 2.1, p = 0.021), duration of diabetes in years (OR = 1.05, p = 0.023), current use of angiotensin-converting enzyme inhibitor (OR = 2.26, p = 0.008) and number of diabetic complications (OR = 1.45, p = 0.028). CONCLUSIONS There is little difference in the prevalence of albuminuria related to patients' willingness to participate in a screening program. Therefore, there are no disproportionate gains for family practice researchers who aggressively seek difficult-to-recruit patients in this set ting. In contrast, primary care doctors should make every effort to ensure optimal care to diabetic patients regardless of a patient's initial hesitancy.