Proposal for a Global Adherence Scale for Acute Conditions (GASAC): A prospective cohort study in two emergency departments

BACKGROUND: Adherence in the context of patients with acute conditions is a major public health issue. It is neglected by the research community and no clinically validated generic scale exists to measure it. OBJECTIVE: To construct and validate a Global Adherence Scale usable in the context of Acute Conditions (GASAC) that takes into account adherence both to advice and to all types of prescriptions that the doctor may give. To measure adherence and to study its determinants. MATERIALS AND METHOD: We based the construction of the GASAC questionnaire on a theoretical model and a literature search. Then, between 2013 and 2014, we validated it in a prospective observational study in two hospital emergency departments. Patients were contacted by phone about one week after their consultation to answer several questionnaires, including GASAC and the Girerd self-administered questionnaire about medication adherence as a control. RESULTS: GASAC consists of four adherence subscales: drug prescriptions; blood tests/ radiography prescriptions; lifestyle advice and follow-up instructions. An analysis of the 154 sets of answers from patients showed that the GASAC drug subscale had satisfactory internal coherence (Cronbach’s alpha = 0.78) and was correlated with the Girerd score, as was GASAC as a whole (p<0.01). The median score was 0.93 IQR [0.78–1] for a maximum value of 1 (n = 154). In multivariaable analysis, infection was more conducive of good adherence (cut off at ≥ 0.8; n = 115/154; 74.7% [67.0–81.3]) than trauma (OR 3.69; CI [1.60–8.52]). The Doctor-Patient Communication score (OR 1.06 by score point, CI [1.02–1.10]) also influenced adherence. CONCLUSIONS: GASAC is a generic score to measure all dimensions of patient adherence following emergency departments visits, for use in clinical research and the evaluation of clinical practice. The level of adherence was high for acute conditions and Doctor-Patient Communication was a major determinant of adherence.