DOI: 10.5061/dryad.8cz8w9gsq
title: Psychometric properties of intentional and unintentional non-adherence measurement tools

description: Background: Distinguishing intentional from unintentional non-adherence
 (persistent forgetfulness) is key when contemplating interventions to
 optimise medication adherence. Objective: To categorise
 patient-reported-outcome measures (PROM) into their propensity to detect
 intentional and unintentional non-adherence to medication, and to
 synthesise their psychometric properties. Design: Review’s conduct and
 reporting were based on the PRISMA-2020 checklist and COSMIN-2018
 guidelines. We searched publications from January 1980 –1 March 2022 in
 MEDLINE, EMBASE, CINAHL, International Pharmaceutical Abstracts and
 Cochrane Library. Articles describing the PROM development and validation
 of the scoring methods to categorise patients into non or
 adherent, and those which incorporated a proxy measure for adherence were
 included. We assessed the quality of studies using the COSMIN risk of bias
 tool and included studies which described a minimum of 2 psychometric
 properties. Open-ended PROM items, which were without a method of scoring,
 or translated versions were excluded. To ensure an exhaustive binning
 process, 2 reviewers independently evaluated and coded every
 criterion-item for possible inclusion into both an outcome and a process
 domain bin deemed fit. Outcomes: Outcome domain-bins were intentional,
 unintentional or mixed. Process domains were behaviour (e.g.,
 self-efficacy), barrier (e.g., impaired dexterity), or belief (e.g.,
 perception). PROM were assigned an overall category of either
 intentional(I), unintentional (UI) or mixed (UI/I) depending on the
 collective leading domain of the individual criterion-items. Results: 59
 PROM were validated among patients aged 18 to 85 years in the USA and UK,
 Europe (Netherlands, Belgium, France, Spain, Switzerland), Middle East
 (Turkey) and Australasia (Malaysia, China,
 Australia).  44 PROM were primarily intentional (I=491
 criterion-items) while 13 were mixed (I=79/ UI=50) and the remaining 2,
 unintentional (UI=5). The corresponding process domains were belief (n=383
 items), barrier (n=192 items), and behaviour (165 items). Psychometrics
 evaluation revealed heterogeneity for: i) PROM definitions – severity
 cut-off scores, and scoring method (ordinal, dichotomised, visual analogue
 scale), and for ii) criterion validity –varied proxy
 measures  used (biomarkers, pill count, electronic
 monitors). One’s belief, behaviour, and barriers encountered were likely
 indicators for I, UI and mixed U/I non-adherence respectively. Conclusion:
 Medication non-adherence that is primarily intentional, is highly
 prevalent. Eight  intentional and 2 partial
 intentionality PROM exhibited adequate psychometric properties.
 Fortification of patients’ knowledge and illness perception, as opposed to
 daily reminders alone, is necessary.
description: After the process of searching and selecting articles based on
 the inclusion and exclusion criteria for patient reported outcome measures
 of non-adherence, we employed an additional step of binning each criterion
 of every PROM. PROMs are essentially made up of sets of criteria and the
 scoring can be ordinal, intergral, or with interval ratio etc. The total
 score determines whether a patient is adherent or non.  Data were collated
 from the PROMs and each of their criterion was binned into 2 groups of
 domain - process and outcome. We binned criterion on
 "behaviour", "barrier" and "belief" into
 process domain-bins, and "unintentional",
 "intentional" and "mixed" into outcome
 domain-bins. Data was collated for n=59. The variables were tabulated and
 each PROM had numerical variables containing number of items in:
 "intentional", unintentional" and "mixed",
 "behaviour", "barrier", "belief" and string
 variables for "condition/ disease/ setting" and "age
 category".