Related Experiment Video
Updated: Aug 18, 2026

Inverse Probability of Treatment Weighting (Propensity Score) using the Military Health System Data Repository and National Death Index
Published on: January 8, 2020
Developing prevalence-based prescribing units for analysing variations in general practitioner prescribing: a case
P R Ward1, P R Noyce, A S St Leger
1School of Social Sciences and Law, Sheffield Hallam University, Sheffield, UK. p.r.ward@shu.ac.uk
Objective:
To develop regionally specific prevalence-, age- and sex-standardized prescribing units (PASS-PUs) and to relate these to statin prescribing.
Design:
Cross-sectional.
Setting:
Ninety-four general practitioner (GP) practices within one health authority in the north-west of England.
Main Outcome Measures:
Comparisons between specific therapeutic group age-sex-related prescribing units (STAR-PUs) and PASS-PUs for statin prescribing.
Results:
STAR-PUs and PASS-PUs were calculated for all GP practices and there was a high degree of correlation (Spearman's rank coefficient 0.88; P < 0.001). Using actual prescribing data for statins for a 12-month period, a statistically significant correlation was found between net ingredient cost per patient and STAR-PUs per patient (Spearman's rank coefficient 0.36; P < 0.01). However, the correlation between average daily quantities per patient and PASS-PUs per patient was not statistically significant. A scatter plot revealed a pattern whereby GP practices with high proportions of patients aged over 75 years exhibited low statin prescribing in relation to the expected prevalence of treated coronary heart disease (CHD) in their patient population.
Conclusions:
Low weightings for patients aged over 75 years in calculating STAR-PUs lead to a much lower number of prescribing units within GP practice populations when compared with PASS-PUs. Current statin prescribing across GP practices in this study correlates with national prescribing cost patterns (as measured by STAR-PUs) although not with expected prevalence of treated CHD (as measured by PASS-PUs). PASS-PUs reflect prevalence of treated CHD and may therefore be used to monitor and predict GP prescribing arising from the implementation of the National Service Framework targets for CHD. In addition, PASS-PUs maybe derived for a wide range of therapeutic areas.
Related Concept Videos
Prescription, Nonprescription and Orphan Drugs
The misuse and addiction to prescription drugs is a growing problem that can affect people of all age groups, specifically teenagers. This can happen when prescription medications are used in ways not intended by the prescriber, such as taking someone else's prescription or using medication for...
Lipid-Lowering Drugs: Statins and Miscellaneous Agents
Analysis of Population Pharmacokinetic Data
Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast, controlled...
Dosage Regimens: Designs and Approaches
Dosage Regimen: Individualization