Measuring therapy adherence in Parkinson’s disease: a comparison of methods

The objective of this study was to assess different methods of measuring therapy adherence in Parkinson’s disease (PD). In a single centre observational study, 112 patients with idiopathic PD were randomised to a crossover trial of active monitoring (n = 69, simple tablet count and electronic monitoring), or to no monitoring (n = 43, control group). All patients completed a self report and visual analogue scale (VAS) indicating therapy intake. In the active monitoring group, 56 (81% of cases) used ⩾80% of their medication, and 13 (19% of cases) used <80%, based on electronic monitoring. Median adherence for self report was 100% (interquartile range (IQR) 100 to 100) and for VAS was 100% (IQR 95 to 100), in both active and control groups. Patients taking ⩾80% of prescribed medication had a median total adherence of 98% (IQR 93 to 101) by electronic monitoring, which was similar to that from other methods: self report 100%, IQR 100 to 100; VAS 100%, IQR 95 to 100; simple tablet count 98%, IQR 89 to 100. Median total adherence in patients taking <80% of medication was significantly lower by electronic monitoring (69%, IQR 44 to 74) than by other methods: self report 100%, IQR 100 to 100; VAS 100%, IQR 95 to 100; and simple tablet count 90%, IQR 78 to 100 (all p<0.0001). Sensitivities of self report (10%), VAS (17%), and simple tablet count (50%) were all low for detecting suboptimal medicine intake. Self report, VAS, and simple tablet counts are insensitive as predictors of suboptimal medicine usage in PD. How patients take their medicines influences interpretation of the therapy response and consequent management decisions, with implications for clinical trial analysis and clinical practice.

[1]  C. Rand,et al.  Noncompliance and treatment failure in children with asthma. , 1996, The Journal of allergy and clinical immunology.

[2]  R B Haynes,et al.  Patient compliance and the conduct and interpretation of therapeutic trials. , 1987, Controlled clinical trials.

[3]  R. Brian Haynes,et al.  Compliance in Health Care , 1979 .

[4]  John Urquhart,et al.  Patient compliance in rheumatoid arthritis, polymyalgia rheumatica, and gout. , 2003, The Journal of rheumatology.

[5]  P. Rudd,et al.  Pill count measures of compliance in a drug trial: variability and suitability. , 1988, American journal of hypertension.

[6]  Safety and efficacy of pramipexole in early Parkinson disease. A randomized dose-ranging study. Parkinson Study Group. , 1997, JAMA.

[7]  P. Rudd,et al.  The natural history of medication compliance in a drug trial: Limitations of pill counts , 1989, Clinical pharmacology and therapeutics.

[8]  J Urquhart,et al.  Role of patient compliance in clinical pharmacokinetics. A review of recent research. , 1994, Clinical pharmacokinetics.

[9]  J. Hughes,et al.  Accuracy of clinical diagnosis of idiopathic Parkinson's disease: a clinico-pathological study of 100 cases. , 1992, Journal of neurology, neurosurgery, and psychiatry.

[10]  Keith C. Norris,et al.  Assessing medication adherence by pill count and electronic monitoring in the African American Study of Kidney Disease and Hypertension (AASK) Pilot Study. , 1996, American journal of hypertension.

[11]  O. Rascol,et al.  Ropinirole in the treatment of early Parkinson's disease: A 6‐month interim report of a 5‐year levodopa‐controlled study , 1998, Movement disorders : official journal of the Movement Disorder Society.

[12]  R C Peveler,et al.  Compliance with tricyclic antidepressants: the value of four different methods of assessment. , 2000, British journal of clinical pharmacology.

[13]  C. Macintyre,et al.  Patient knows best: blinded assessment of nonadherence with antituberculous therapy by physicians, nurses, and patients compared with urine drug levels. , 2005, Preventive medicine.

[14]  R. Straka,et al.  Patient Self‐Reporting of Compliance Does Not Correspond with Electronic Monitoring: An Evaluation Using Isosorbide Dinitrate as a Model Drug , 1997, Pharmacotherapy.

[15]  L. Green,et al.  Concurrent and Predictive Validity of a Self-reported Measure of Medication Adherence , 1986, Medical care.

[16]  B. Svarstad,et al.  The Brief Medication Questionnaire: a tool for screening patient adherence and barriers to adherence. , 1999, Patient education and counseling.

[17]  A. Lawrence,et al.  Compulsive use of dopamine replacement therapy in Parkinson's disease: reward systems gone awry? , 2003, The Lancet Neurology.

[18]  A. Burgess,et al.  Reasons for non-adherence to antiretroviral therapy: Patients' perspectives provide evidence of multiple causes , 2001, AIDS care.

[19]  John Urquhart,et al.  Role of Patient Compliance in Clinical Pharmacokinetics , 1994 .

[20]  J. Cramer.  A Systematic Review of Adherence With Medications for Diabetes , 2004 .

[21]  Marcia Polansky,et al.  Drug adherence in Parkinson's disease , 2004, Movement disorders : official journal of the Movement Disorder Society.

[22]  J. Cramer,et al.  How often is medication taken as prescribed? A novel assessment technique. , 1989, JAMA.

[23]  P. Rudd,et al.  Improved compliance measures: Applications in an ambulatory hypertensive drug trial , 1990, Clinical pharmacology and therapeutics.

[24]  E. D. Myers,et al.  Information, compliance and side-effects: a study of patients on antidepressant medication. , 1984, British journal of clinical pharmacology.

[25]  J. Cramer.  A systematic review of adherence with medications for diabetes. , 2004, Diabetes care.

[26]  Glenys A. Hamilton,et al.  Measuring Adherence in a Hypertension Clinical Trial , 2003, European journal of cardiovascular nursing : journal of the Working Group on Cardiovascular Nursing of the European Society of Cardiology.