Schneeweiss et al. [ 47] observed that in a population of older adults, comorbidity measures based on medication codes had poorer performance than measures based on diagnosis codes.
25 Currently, the two most commonly used measures of medication adherence based on pharmacy data are the medication possession ratio and the PDC methods.
Adherence to medication was assessed using self-report and tablet count data, and while both only provided indirect measures of medication adherence, relying heavily on various assumptions (eg, accurate participant recall, returning of all unused medication), both measures were often available for the same individual, allowing for the assessment of agreement between measures.
Self-report measures of medication nonadherence confound the extent of and reasons for medication nonadherence.
Medical comorbidity was adjusted using RxRISK, an empirically derived comorbidity measure based on medications patients take to manage chronic diseases (20).
This improvement project delivered feedback of prescribing errors to prescribers in the neonatal intensive care unit (NICU), and measured the impact on medication error frequency.
The ESR is more likely to be measured in children on medication requiring blood monitoring, meaning that children with persistent oligoarticular JIA (the most common category) are less likely to have an ESR available than children with systemic onset JIA or a polyarticular disease pattern.
For the biochemical phenotypes, analyses were performed in cases only, and these were on medication measures.
This effectiveness has not necessarily translated into a favorable impact on clinical measures of effect or on medication adherence.
The lack of a universal guideline on medication adherence measures provides rooms for research on which measure, or which combination of measures, is the most appropriate for different target populations and health problems.
