Does point-of-care testing lead to the same or better adherence to medication? A randomised controlled trial: the PoCT in General Practice Trial

Objective: To compare the clinical effectiveness of point-of-care testing (PoCT) with that of pathology laboratory testing as measured by patients' adherence to medication. Design: Multicentre, cluster randomised controlled trial using non-inferiority analysis. Medication adherence was assessed twice (in April 2006 and January 2007) by a self-administered questionnaire using the five-item Medication Adherence Report Scale (MARS-5). Setting: 53 Australian general practices in urban, rural and remote areas across three Australian states, September 2005 to February 2007. Participants: 4968 patients with established type 1 or type 2 diabetes, established hyperlipidaemia, or requiring anticoagulant therapy were recruited to the study. Of these, 4381 were included in the analysis (2585 in the intervention group and 1796 in the control group). Intervention: The intervention group (3010 patients in 30 practices) had blood and urine samples tested using PoCT devices within their general practices. The control group (1958 patients in 23 practices) had samples tested by their usual pathology laboratories. Main outcome measures: The proportion of questionnaire responses indicating medication adherence overall and by condition. Results: PoCT was non-inferior to pathology laboratory testing in relation to the proportion of questionnaire responses indicating medication adherence (39.3% v 37.0%) (difference, 2.3% [90% CL, -0.1 %, 4.6%]; P < 0.001). Non-inferiority could also be concluded separately for patients with diabetes (38.5% v 37.3%) (difference, 1.2% [90% CL, -2.5%, 5.0%]; P = 0.01); hyperlipidaemia (38.3% v 37.3%) (difference, 1.0% (90% CL, -1.5%, 3.5%]; P < 0.001) and for patients requiring anticoagulant therapy (44.5% v 41.4%) (difference, 3.1% [90% CL, -2.1%, 8.3%1; P = 0.01). Conclusions: Having access to immediate test results through PoCT is associated with the same or better medication adherence compared with having test results provided by a pathology laboratory. PoCT used in general practice can provide general practitioners and patients with timely and complete clinical information, facilitating important self-management behaviours such as medication adherence.