Table 1B

Definitions, cut-points and per cent adherence/compliance across studies. Studies were placed into subgroups according to the method used to measure adherence. Scale and cut-points used to rate adherence are also shown.

StudiesOutcomeDefinition/scaleCut-point for adherence/
compliance
Adherence
%
Prescription claims
Sarawate et al, 200617 ComplianceMPR was calculated as medication supply actually received divided by medication supply that could have been received.MPR≥80%28
Briesacher et al, 200818 AdherenceMPR defined as the days supply of the drug dispensed during the follow-up year divided by the number of days in the year.MPR≥80%36.8
Harrold et al, 200924 AdherenceMPR defined as the days supply of medication dispensed during the follow-up year divided by the number of days in the year and is a reliable measure of adherence.MPR≥80%44
Halpern et al, 200930 ComplianceMPR: sum of days supply from first observed allopurinol fill during the 2-year observation period divided by the number of days between the first observed fill and the end of the postindex period.MPR≥80%44
Rashid et al, 201229 AdherenceAdherence was measured using the MPR over the follow-up time period.MPR>80%47.5*
Horsburgh et al, 201419 AdherenceMPR defined as the ratio of days supplied from initial dispensing to the number of days to the end of the study period or the patient’s date of death.MPR≥80%78*
Singh, 201423 AdherenceSelf-report adherence to ULT.MPR≥0.8032.6*
McGowan et al, 201622 AdherenceMPR defined as the number of doses filled by the pharmacist divided by the number of days in the defined period (6 or 12 months).MPR≥80%45.5
Tan et al, 201632 AdherenceMPR summarised the proportion of days a patient has a supply of medications for.MPR≥80%83.5
Solomon et al, 200821 AdherencePDC was calculated as the days with available UALT divided by the total number of days of follow-up.PDC≥80%36*
Park et al, 201226 AdherencePDC defined as the number of days during the study period (365 days) that the patient had at least one gout-specific medication on hand.PDC≥80%26.9*
Zandman-Goddard et al, 201320 AdherenceMean PDC calculated by dividing the quantity of allopurinol dispensed by the total time interval from index date to drug cessation, death, leaving MHS or 31 December 2009, whichever occurred first.PDC≥80%17
Mantarro et al, 201531 AdherencePDC defined as dividing the cumulative days of medication use by the length of follow-up.PDC≥80%45.9
Rashid et al, 201527 AdherencePDC was defined as the number of days with ULT drug dispensed divided by the number of days in the specified time interval (365 days).PDC≥80%48.2*
Kuo et al, 201528 AdherencePDC defined as the period from the latest of registration date or 1 January to the earliest of transfer-out, death date or 31 December of the calendar year specified.PDC≥80%39.66
Riedel et al, 200425 ComplianceCompliance was defined for each prescription period as the presumed use of allopurinol on at least 80% of the days of that period.Compliance rate≥80%18
Pill count
Lee et al, 201633 CompliancePill counts: non-compliance was defined as <80% of the prescribed dose taken.Pill count≥80%71.2
Self-report
Silva et al, 201035 ComplianceCompliance defined as taking medication regularly, as prescribed.NS53*
Singh et al, 201634 AdherenceNumber of days the patient forgot to take ULT in the last month.Adherence>0.8078.5
Tan et al, 201632 AdherenceMMAS-8 used to measure medication adherence (eight items, total score ranges 0–8).MMAS-8 score≥6 (75%)61.9
Interview
Martini et al, 201236 ComplianceParticipants admitted to not taking ULTs as prescribed.NS79
Sheng et al, 201438 AdherenceAdherence was defined as sustained use of ULD in the prior 12 months, otherwise non-adherence.NS53.8*
van Onna et al, 201537 AdherenceNon-adherence at some point in time was defined as admission in the interview.NS50.0*
  • *Calculated based on data provided in the article.

  • MMAS-8, 8-item Morisky Medication Adherence Scale; MPR, medication possession ratio; NS, not stated; PDC, proportion of days covered; UALT, uric acid-lowering therapy; ULD, urate-lowering drug; ULT, urate-lowering therapy.