Predictive Validity of Self-Reported Measures of Adherence to Noninsulin Antidiabetes Medication against Control of Glycated Hemoglobin Levels.
OBJECTIVE
To assess and compare the predictive validity of 4 self-reported adherence measures.


METHODS
A convenience sample of 153 patients with type 2 diabetes completed a self-report with 4 items (SR-4) and a French version of the Morisky Medication Adherence Scale with 8 items (MMAS-8), reported the proportion of pills missed, and answered a single-item scale regarding their antidiabetes drug treatments. They also provided measures of glycated hemoglobin (A1C) taken between 3 and 6 months after the adherence measurements. We examined the relationship between self-reported adherence and glycemic control using the area under the receiver operating characteristics curve (AUC) and linear regression analyses.


RESULTS
AUCs were 0.51, 0.52, 0.53 and 0.52 for the SR-4, MMAS-8, self-reported proportion of pills missed and single-item scale, respectively. AUCs stratified according to median duration of diabetes ranged from 0.55 to 0.63. Based on linear regression analyses adjusted for diabetes duration, the association measured in the total sample between adherence measures and A1C levels was not statistically significant. When regression analyses were performed among participants with A1C levels ≥7% only, SR-4, MMAS-8 and the single-item scale scores were significantly associated with A1C levels, and beta coefficients were associated with a 1-unit increase in adherence scores of -0.46, -0.20 and 0.38, respectively.


CONCLUSIONS
The results support the predictive validity of all measures except the self-reported proportion of missed pills.
Faculty of Pharmacy, Laval University, Quebec City, Quebec, Canada; Chair on Adherence to Treatments, Laval University, Quebec City, Quebec, Canada; Population Health and Optimal Health Practices Research Unit, CHU de Québec Research Centre, Quebec City, Quebec, Canada.
Arsène
A
Zongo
Faculty of Pharmacy, Laval University, Quebec City, Quebec, Canada; Chair on Adherence to Treatments, Laval University, Quebec City, Quebec, Canada; Population Health and Optimal Health Practices Research Unit, CHU de Québec Research Centre, Quebec City, Quebec, Canada.
Line
L
Guénette
Faculty of Pharmacy, Laval University, Quebec City, Quebec, Canada; Chair on Adherence to Treatments, Laval University, Quebec City, Quebec, Canada; Population Health and Optimal Health Practices Research Unit, CHU de Québec Research Centre, Quebec City, Quebec, Canada.
Jocelyne
J
Moisan
Faculty of Pharmacy, Laval University, Quebec City, Quebec, Canada; Chair on Adherence to Treatments, Laval University, Quebec City, Quebec, Canada; Population Health and Optimal Health Practices Research Unit, CHU de Québec Research Centre, Quebec City, Quebec, Canada. Electronic address: Jean-Pierre.Gregoire@pha.ulaval.ca.
Jean-Pierre
JP
Grégoire
D000284:Administration, Oral; D000368:Aged; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy*; D004359:Drug Therapy, Combination; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D006943:Hyperglycemia / Q000517:prevention & control*; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D020407:Internet; D016014:Linear Models; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D011792:Quebec; D012372:ROC Curve; D057566:Self Report; D011795:Surveys and Questionnaires
D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; C517652:hemoglobin A1c protein, human
autodéclaration; diabète de type 2; glycemic control (A1C); maîtrise de la glycémie (A1c); medication adherence; noninsulin antidiabetic treatment; observance du traitement; predictive validity; self-report; traitement antidiabétique non insulinique; type 2 diabetes; validité prédictive