biostudies-literatureUnknown6(5)Sidorkiewicz S<h4>Objective</h4>To develop and validate an instrument to assess adherence to each individual drug taken by patients undergoing long-term treatment.<h4>Design</h4>Multicentre prospective observational validation study.<h4>Setting</h4>Six general practitioners' clinics and 6 university hospitals in Paris, France.<h4>Participants</h4>Patients 18 years and older receiving at least one long-term treatment.<h4>Methods</h4>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 BMJ opene010510https://www.ebi.ac.uk/biostudies/studies/S-EPMC4874131biostudies-literatureDevelopment and validation of an instrument to assess treatment adherence for each individual drug taken by a patient.PMC4874131Perrodeau ECousyn CSidorkiewicz STran VTRavaud PfalseDevelopment and validation of an instrument to assess treatment adherence for each individual drug taken by a patient.<h4>Objective</h4>To develop and validate an instrument to assess adherence to each individual drug taken by patients undergoing long-term treatment.<h4>Design</h4>Multicentre prospective observational validation study.<h4>Setting</h4>Six general practitioners' clinics and 6 university hospitals in Paris, France.<h4>Participants</h4>Patients 18 years and older receiving at least one long-term treatment.<h4>Methods</h4>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 2016-01-01T00:00:00Z2016 May2026-07-15T20:17:06.122Z2026-07-09T03:10:29.523ZS-EPMC48741312716564510.1136/bmjopen-2015-010510