A systematic review of the prevalence and determinants of nonadherence to phosphate binding medication in patients with end-stage renal disease

Christina Karamanidou¹ , Jane Clatworthy¹ , John Weinman² and Rob Horne¹

¹Centre for Behavioural Medicine, The School of Pharmacy, University of London, Mezzanine Floor, BMA House, Tavistock Square, London WC1H 9JP, UK

²Health Psychology Section, Institute of Psychiatry, University of London, 5th floor Thomas Guy House, London Bridge, London SE1 9RT, UK

author email corresponding author email

BMC Nephrology 2008, 9:2doi:10.1186/1471-2369-9-2


Published:	31 January 2008

Abstract

Background

Cardiovascular events are the leading cause of death in end stage renal disease (ESRD). Adherence to phosphate binding medication plays a vital role in reducing serum phosphorus and associated cardiovascular risk. This poses a challenge for patients as the regimen is often complex and there may be no noticeable impact of adherence on symptoms. There is a need to establish the level of nonadherence to phosphate binding medication in renal dialysis patients and identify the factors associated with it.

Methods

The online databases PsycINFO, Medline, Embase and CINAHL were searched for quantitative studies exploring predictors of nonadherence to phosphate binding medication in ESRD. Rates and predictors of nonadherence were extracted from the papers.

Results

Thirty four studies met the inclusion criteria. There was wide variation in reported rates of non-adherence (22–74% patients nonadherent, mean 51%). This can be partially attributed to differences in the way adherence has been defined and measured. Demographic and clinical predictors of nonadherence were most frequently assessed but only younger age was consistently associated with nonadherence. In contrast psychosocial variables (e.g. patients' beliefs about medication, social support, personality characteristics) were less frequently assessed but were more likely to be associated with nonadherence.

Conclusion

Nonadherence to phosphate binding medication appears to be prevalent in ESRD. Several potentially modifiable psychosocial factors were identified as predictors of nonadherence. There is a need for further, high-quality research to explore these factors in more detail, with the aim of informing the design of an intervention to facilitate adherence.