MP679
ADHERENCE TO PHOSPHATE BINDERS (PB) IN HEMODIALYSIS (HD) PATIENTS: PARADOXICAL IMPACT OF DAILY DOSAGE (NATIONAL SURVEY OF 1,290 HD PATIENTS)

INTRODUCTION AND AIMS: PB are a significant part of the daily pill burden, potentially influencing adherence and control of hyperphosphatemia (HP). Because HP is associated with higher mortality, adherence to PBs and its factors must be evaluated in order to be corrected if needed. Adherence can be estimated by a patient survey using a validated questionnaire. The objective of this study is to evaluate adherence to PB and associated factors in Nephrocare dialysis centers

METHODS: A questionnaire derived from the Morisky scale is administered to patients (by nurses or self-administration). We collected demographic datas, daily pill burden, patient awarness of HP and PB, adherence to PB and factors that may influence adherence.

RESULTS: 1290 pts included ( 69 years), HD vintage > 3 years (47%), pill burden of 8 to +12 pills/d (48%), “phosphorus awarness”(63%), ignorance of HP complications (67%), pill burden of 3 to +8 pill/d (46%), "total adherence" to PB (71%). Among non-adherent patients, 50% "forget" and 16% "don’t tolerate" their PB. The increase of daily PB burden is associated with a non-significant increase of adherence. Age, HD vintage, dialysis center have no influence on PB adherence.

CONCLUSIONS: PB daily burden and reasons of “non-adherence" are similar to DOPPS results. Nevertheless, positive correlation between "PB burden" and "adherence" invalidates DOPPS results but confirms study of Neri and coll al (Neri et al J. Neph 2011). In our study, association between "PB burden" and "adherence" is modified by a confounding factor ( "burden of treatment” represented by PB : number of pill, side effects⋯.). This factor was not evaluated in our questionnaire and could explain this unexpected relationship between dosage and adherence. The common idea that adherence is related to the daily number of pills and that a reduced daily dosage would improve adhesion should be qualified. This result confirms the importance of therapeutic education.