Authors : EricHachullaNoémie LeGouellecDavidLaunayMarie-HélèneBalquetHélèneMaillardRaymondAzarAmalBoldronPierreBatailleMarcLambertAnne-LaureBuchdahlDelphineAllorgePierre-YvesHatronVincentSobanskiBenjaminHennartPierreClersonSandrineMorell-Duboisthe ESSTIM Investigators group
Hydroxychloroquine (HCQ) is an anchor drug in the treatment of systemic lupus erythematosus (SLE). Adherence to HCQ is key for efficacy. Inaccurate evaluation of adherence could lead to non-justified switch to more expensive or less tolerated drugs.
Severe non-adherence rate to HCQ was estimated in a sample of SLE patients during a routine visit using blood HCQ concentration < 200 µg/L. Adherence was assessesd by the Medication Adherence Self-Report Inventory (MASRI) < 80/100, 8-item Morisky Medication Adherence Scale (MMAS-8) ≤ 6 /8, Health Care Provider (HCP) visual analog scale (VAS) < 80/100. Same procedures were to be repeated during a further routine visit 6 to 12 months later. We described agreement and correlations between tools and compared severely non-adherent patients and others on their characteristics.
The study involved 158 patients (86.1% females) aged 42.2±12.6 years treated with HCQ for 9.6±6.9 years. Blood HCQ concentration (mean±standard deviation) was 1046±662 µg/L at visit 1 and 855±577 µg/L at visit 2. At visit 1, the non-adherence rate varied from 3.2% (blood HCQ level < 200 µg/L) to 7.7% (MASRI), 12.4% (HCP-VAS) or 32.5% (MMAS-8). 37.8% of patients met at least one of the definitions of non-adherence. Patients’ characteristics including SLE activity, damage and quality of life were similar between severely non-adherent patients and others. Correlations between blood HCQ-concentration and self-questionnaires were weak (r <0.25) and agreement between methods was poor.
Blood HCQ concentration < 200 µg/L reveals severe non-adherence. Combining blood HCQ concentration with MASRI and MMAS-8 may help to better identify non-adherence in SLE. Agreement between methods was poor and correlations with HCQ level and SLE activity were weak.