Adherence to treatment in patients with type 2 diabetes

Since there is no gold-standard method of measuring adherence, one of the main difficulties in managing low adherence is a lack of accurate and affordable measures. Clinicians must frequently rely on their own judgement, but unfortunately demonstrate no better than chance accuracy in predicting the adherence of their patients (Stephenson et al, 1993), even among those for whom they feel confident about their predictions (Gilbert et al, 1980). Based on a systematic review of studies of adherence measures (Stephenson et al, 1993), asking nonresponders about their adherence will detect more than 50 % of those with low adherence, with a specificity of 87 % (Haynes et al, 2002). Even when people indicate that they have not taken all their medications as prescribed, their estimates usually substantially overestimate their actual adherence. The key validated question is ‘Have you missed any pills in the past week?’ and any indication of having missed one or more pills signals a problem with low adherence. Overestimation of adherence by patients is difficult to study and is presently poorly documented. Reasons for overestimation could include difficulty recalling the details of medication taking, attempting to please practitioners, to avoid confrontation, or a combination of these factors. Other practical measures to assess Adherence has been defined as the extent to which individuals follow the instructions they are given for prescribed treatments (Haynes et al, 2002). Thus, if a person is prescribed an antibiotic to be taken as one tablet four times a day for a week for an infection, but takes only two tablets a day for five days, their adherence would be (10/28=) 36 %. The term adherence is intended to be nonjudgmental – a statement of fact rather than of blame of the individual, the prescriber, or the treatment. Compliance and concordance are synonyms for adherence. Adherence to treatment is a complex health behaviour. Problems identified include the individual’s failing to initiate therapy, underusing or overusing a treatment, stopping a treatment too soon, and mis-timing or skipping doses (e.g. Ley and Llewelyn, 1995). Non-adherence to treatment is a formidable problem, leading as it often does to a reduction in or lack of treatment benefits, extra visits to the doctor, unnecessary hospitalisation, decreased satisfaction with medical care and sometimes further medication prescription. This can be extremely costly, not only to the individual involved, but also to the healthcare system as a whole. Nonadherence persists regardless of the medical condition being treated and exists across socioeconomic and geographic boundaries (Myers and Midence, 1998). Adherence to treatment in patients with type 2 diabetes