Number of drugs in the medication list as an indicator of prescribing quality: a validation study of polypharmacy indicators in older hip fracture patients

Abstract

PurposeIndicators based on the number of drugs in the medication list are sometimes used to reflect quality of drug treatment. This study aimed to evaluate the concurrent validity of such polypharmacy indicators, i.e., their ability to differentiate between appropriate and suboptimal drug treatment.MethodsIn 200 hip fracture patients (≥65 years of age), consecutively recruited to a randomized controlled study in Sahlgrenska University Hospital in 2009, quality of drug treatment at study entry was assessed according to a gold standard as well as to indicators based on the number of drugs in the medication list. As gold standard, two specialist physicians independently assessed and then agreed on the quality for each patient, after initial screening with Screening Tool of Older Persons’ potentially inappropriate Prescriptions (STOPP) and Screening Tool to Alert to Right Treatment (START). Suboptimal drug treatment was defined as ≥1 STOPP/START outcomes assessed as clinically relevant at the individual level.ResultsA total of 141 (71 %) patients had suboptimal drug treatment according to the gold standard. The corresponding figures according to the indicators ≥5 and ≥10 drugs were 149 (75) and 49 (25 %), respectively. The sensitivity for the indicators ≥5 and ≥10 drugs to detect suboptimal drug treatment was 0.86 (95 % confidence interval: 0.80; 0.92) and 0.32 (0.25; 0.40), respectively. The specificity was 0.53 (0.41; 0.65) and 0.93 (0.82; 0.97).ConclusionsThe findings suggest that no polypharmacy indicator could serve as a general indicator of prescribing quality; cut-offs for such indicators need to be chosen according to purpose.

The First Decade with the Swedish Prescribed Drug Register – A Systematic Review of the Output in the Scientific Literature

“…In this context, it may be of interest to point at recent validation studies. Indeed, although often used in pharmacoepidemiological research, polypharmacy indicators give limited information on the quality of drug treatment [22]. However, the number of drugs in the medication list may be a valuable proxy for burden of disease [23].…”

Essential medicines for universal health coverage

“…Indicators based on pharmaceutical data alone help focus attention on key issues, including highlighting variation among providers or from an expected norm (table 7).The more that data across dimensions can be linked, the more detailed the questions addressed and conclusions can be. [343][344][345] Indicator validity is important, but limitations in measurability should not deter from focusing on important issues. If validity limits a system to focusing-and acting-only on indicators that are easily measurable, it could skew resource allocation to the detriment of either priority medicines use issues or patient groups with less data.…”

Clinician agreement and influence of medication‐related characteristics on assessment of polypharmacy

“…However, the number of medications may not be the best indicator of prescribing quality in a clinical setting and differentiation between appropriate and inappropriate polypharmacy may be more relevant (Belfrage et al. ; Garfinkel and Bahat ; Scott et al. ).…”