Drug utilization studies and data registries in primary care

This article reviews the methodology of the studies on drug utilization with particular emphasis on primary care. Population based studies of drug inappropriateness can be done with microdata from Health Electronic Records and e-prescriptions. Multilevel models estimate the influence of factors affecting the appropriateness of drug prescription at different hierarchical levels: patient, doctor, health care organization and regulatory environment. Work by the GIUMAP suggest that patient characteristics are the most important factor in the appropriateness of prescriptions with significant effects at the general practicioner level.Drug Utilization Studies, Multilevel Models, Primary Care, Health Information Systems, Health Economics.

Does the pharmacy expenditure of patients always correspond with their morbidity burden? Exploring new approaches in the interpretation of pharmacy expenditure

<p>Abstract</p> <p>Background</p> <p>The computerisation of primary health care (PHC) records offers the opportunity to focus on pharmacy expenditure from the perspective of the morbidity of individuals. The objective of the present study was to analyse the behaviour of pharmacy expenditure within different morbidity groups. We paid special attention to the identification of individuals who had higher values of pharmacy expenditure than their morbidity would otherwise suggest (i.e. outliers).</p> <p>Methods</p> <p>Observational study consisting of 75,574 patients seen at PHC centres in Zaragoza, Spain, at least once in 2005. Demographic and disease variables were analysed (ACG^®8.1), together with a response variable that we termed 'total pharmacy expenditure per patient'. Outlier patients were identified based on boxplot methods, adjusted boxplot for asymmetric distributions, and by analysing standardised residuals of tobit regression models.</p> <p>Results</p> <p>The pharmacy expenditure of up to 7% of attendees in the studied PHC centres during one year exceeded expectations given their morbidity burden. This group of patients was responsible for up to 24% of the total annual pharmacy expenditure. There was a significantly higher number of outlier patients within the low-morbidity band which matched up with the higher variation coefficient observed in this group (3.2 vs. 2.0 and 1.3 in the moderate- and high-morbidity bands, respectively).</p> <p>Conclusions</p> <p>With appropriate validation, the methodologies of the present study could be incorporated in the routine monitoring of the prescribing profile of general practitioners. This could not only enable evaluation of their performance, but also target groups of outlier patients and foster analyses of the causes of unusually high pharmacy expenditures among them. This interpretation of pharmacy expenditure gives new clues for the efficiency in utilisation of healthcare resources, and could be complementary to management interventions focused on individuals with a high morbidity burden.</p

Evolución de los estudios de utilización de medicamentos: del consumo a la calidad de la prescripción

Drug utilisation study methodology is revised in this paper, with particular attention to the suitability of medication prescribed in the primary care area. A distinction is drawn between predictive and regulatory studies. The potential and limitations of information systems are explored. With the computerisation of medical histories in Spain, suitability studies using multilevel regression can now be conducted to assign ¿responsibilities¿ for inefficiencies to the various actors involved: patient, physician and organisational or institutional environment. An empirical study on the suitability of the use of proton pump inhibitors is taken as an example to illustrate the methodology proposed.En este artículo se revisa la metodología de los Estudios de Utilización de Medicamentos (EUM), prestando especial atención a los de adecuación de la prescripción y al ámbito de atención primaria. Se diferencia entre estudios predictivos y normativos. Se exploran las posibilidades y limitaciones de los sistemas de información. La informatización de las historias de salud empieza a permitir en España que los estudios de adecuación, utilizando regresión multinivel, asignen «responsabilidades» de la ineficiencia a los niveles que correspondan, paciente, médico, y entorno organizativo o institucional. Se ilustran esas propuestas metodológicas con un estudio empírico de adecuación de inhibidores de la bomba de protones