PT - JOURNAL ARTICLE AU - Stéphanie Sidorkiewicz AU - Viet-Thi Tran AU - Cécile Cousyn AU - Elodie Perrodeau AU - Philippe Ravaud TI - Development and validation of an instrument to assess treatment adherence for each individual drug taken by a patient AID - 10.1136/bmjopen-2015-010510 DP - 2016 May 01 TA - BMJ Open PG - e010510 VI - 6 IP - 5 4099 - http://bmjopen.bmj.com/content/6/5/e010510.short 4100 - http://bmjopen.bmj.com/content/6/5/e010510.full SO - BMJ Open2016 May 01; 6 AB - Objective To develop and validate an instrument to assess adherence to each individual drug taken by patients undergoing long-term treatment.Design Multicentre prospective observational validation study.Setting Six general practitioners' clinics and 6 university hospitals in Paris, France.Participants Patients 18 years and older receiving at least one long-term treatment.Methods The instrument was developed from a literature search and interviews with experts. Clarity and wording were assessed during pilot testing with 51 patients. The tool was validated in a sample of consecutive patients. We assessed agreement between adherence measured with our tool and drug diaries and compared measurements from our instrument with (1) the Lu instrument; (2) the Adherence Estimator (AE); (3) patient's adherence assessed by physicians; (4) the Morisky Medication Adherence Scale-4 items (MMAS-4); and (5) the Treatment Burden Questionnaire (TBQ). Reliability was assessed by a test–retest method.Results A total of 243 patients taking 961 drugs were recruited in 2014. We found good agreement between adherence measured by our tool and drug diaries (intraclass correlation coefficient (ICC) 0.69, 95% CI 0.34 to 0.91) and a linear relationship between measurement with our tool and (1) the Lu instrument (p<0.01); (2) 2 items of the AE (perceived need for medication (p<0.01) and concerns about medication (p<0.01)); (3) patients' adherence assessed by their physicians (p<0.01); (4) the MMAS-4 (p<0.01) and (5) the TBQ (p<0.01). Reliability of the retest was good (ICC 0.67, 95% CI 0.42 to 0.85).Conclusions We developed an instrument with acceptable validity and reliability to assess adherence for each drug taken by patients, usable in hospital and primary care settings.