BTS 2014 Report: Non-adherence: measuring the size of the problem

Maria Dalby reporting on the presentation by Brian Camilleri, Ipswich Hospital, Ipswich – Non-adherence to immunosuppressive treatment post-transplantation is common and may have calamitous consequences for short- and long-term outcomes. Brian Camilleri, consultant nephrologist at Ipswich Hospital, reported on the findings of a survey amongst transplant recipients which showed that patients using once-daily medication were significantly more likely to be adherent, and that younger patients are more likely to be non-adherent than older patients.

The main obstacle when designing adherence studies is which tool to use – electronic monitoring tools such as was used in the recently published ADMIRAD study [1] are highly accurate, but are also expensive and labour-intensive to use and thus not well suited for use in clinical practice. A number of self-reporting tools are available – a systematic review found that only a handful are suitable for use in transplantation patients [2], and Dr Camilleri and his team duly chose the Basel Assessment of Adherence to Immunosuppressive Medications Scale (BAASIS) tool for interviewing patients attending Ipswich Hospital following renal transplantation in Cambridge. A total of 176 patients were interviewed – 60 patients were treated with once-daily tacrolimus and 10 patients received sirolimus; the remainder were on twice-daily medication in the form of either cyclosporine (52 patients) or twice-daily tacrolimus (54 patients). Two-thirds (62%) of patients were male, 40% were in employment, mean age was 52 years and time since transplantation ranged from 4 months to 28 years.

Around one in three patients (36%) reported that they were non-adherent, which is consistent with the published literature. Further, 13% reported that they had missed a single dose of medication, and 28% had mistimed a dose. There was a correlation between adherence and dosing frequency, with around 40% of patients on twice-daily medication being non-adherent compared with around 30% using once-daily medication, although this difference did not reach statistical significance (p=0.071). Patients on once-daily medication were also significantly less likely to miss a dose compared with patients on twice-daily medication (7% vs 17%, p=0.045). Patients under the age of 40 years were significantly less adherent than older patients (p=0.014) and there was a similar trend towards patients in employment being less adherent than non-employed patients, although the latter did not reach statistical significance (p=0.057). There was also a non-significant trend towards better adherence in patients transplanted more recently, which Dr Camilleri hypothesised may be linked with increased use of once-daily immunosuppression in recent years. Based on these findings together with the ability of once-daily tacrolimus to improve adherence in renal transplant recipients documented in the ADMIRAD study [1], Dr Camilleri recommended asking about adherence in a non-confrontational way in the clinic and exploring the reasons behind any non-adherence, as well as considering switching to once-daily dosing.

References

1.         Kuypers, D.R., et al., Improved adherence to tacrolimus once-daily formulation in renal recipients: a randomized controlled trial using electronic monitoring. Transplantation, 2013. 95(2): p. 333-40.

2.         Dobbels, F., et al., The psychometric properties and practicability of self-report instruments to identify medication nonadherence in adult transplant patients: a systematic review. Transplantation, 2010. 90(2): p. 205-19.