Vasco Pieri

Prevalence of the Prescription of Potentially Interacting Drugs

The use of multiple medications is becoming more common, with a correspondingly increased risk of untoward effects and drug-related morbidity and mortality. We aimed at estimating the prevalence of prescription of relevant potentially interacting drugs and at evaluating possible predictors of potentially interacting drug exposure. We retrospectively analyzed data on prescriptions dispensed from January 2004 to August 2005 to individuals of two Italian regions with a population of almost 2.1 million individuals. We identified 27 pairs of potentially interacting drugs by examining clinical relevance, documentation, and volume of use in Italy. Subjects who received at least one prescription of both drugs were selected. Co-prescribing denotes “two prescriptions in the same day”, and concomitant medication “the prescription of two drugs with overlapping coverage”. A logistic regression analysis was conducted to examine the predictors of potential Drug-Drug Interaction (pDDIs). 957,553 subjects (45.3% of study population) were exposed to at least one of the drugs/classes of the 27 pairs. Overall, pDDIs occurred 2,465,819 times. The highest rates of concomitant prescription and of co-prescription were for ACE inhibitors+NSAIDs (6,253 and 4,621/100,000 plan participants). Considering concomitance, the male/female ratio was <1 in 17/27 pairs (from 0.31 for NSAIDs-ASA+SSRI to 0.74 for omeprazole+clopidogrel). The mean age was lowest for methotrexate pairs (+omeprazole, 59.9 years; +NSAIDs-ASA, 59.1 years) and highest for digoxin+verapamil (75.4 years). In 13/27 pairs, the mean ages were ≥70 years. On average, subjects involved in pDDIs received ≥10 drugs. The odds of exposure were more frequently higher for age ≥65 years, males, and those taking a large number of drugs. A substantial number of clinically important pDDIs were observed, particularly among warfarin users. Awareness of the most prevalent pDDIs could help practitioners in preventing concomitant use, resulting in a better quality of drug prescription and potentially avoiding unwanted side effects.

ASSET (Age/Sex Standardised Estimates of Treatment): A Research Model to Improve the Governance of Prescribing Funds in Italy

Background The primary objective of this study was to make the first step in the modelling of pharmaceutical demand in Italy, by deriving a weighted capitation model to account for demographic differences among general practices. The experimental model was called ASSET (Age/Sex Standardised Estimates of Treatment). Methods and Major Findings Individual prescription costs and demographic data referred to 3,175,691 Italian subjects and were collected directly from three Regional Health Authorities over the 12-month period between October 2004 and September 2005. The mean annual prescription cost per individual was similar for males (196.13 euro) and females (195.12 euro). After 65 years of age, the mean prescribing costs for males were significantly higher than females. On average, costs for a 75-year-old subject would be 12 times the costs for a 25–34 year-old subject if male, 8 times if female. Subjects over 65 years of age (22% of total population) accounted for 56% of total prescribing costs. The weightings explained approximately 90% of the evolution of total prescribing costs, in spite of the pricing and reimbursement turbulences affecting Italy in the 2000–2005 period. The ASSET weightings were able to explain only about 25% of the variation in prescribing costs among individuals. Conclusions If mainly idiosyncratic prescribing by general practitioners causes the unexplained variations, the introduction of capitation-based budgets would gradually move practices with high prescribing costs towards the national average. It is also possible, though, that the unexplained individual variation in prescribing costs is the result of differences in the clinical characteristics or socio-economic conditions of practice populations. If this is the case, capitation-based budgets may lead to unfair distribution of resources. The ASSET age/sex weightings should be used as a guide, not as the ultimate determinant, for an equitable allocation of prescribing resources to regional authorities and general practices.

Can savings induced by off-patent drugs balance the increase of pharmaceutical expense associated with the high ageing rate of the italian population?

Background : The predicted ageing rate of the Italian population is one of the highest worldwide and this condition is expected to produce a growing increase in pharmaceutical expenditure. The objective of this study was to assess whether or not off-patent drugs could counterbalance the economic effects generated by the aging of the Italian population in the next ten years. Methods : On the basis of the predicted ageing rate of the Italian population for the period 2008-2018, the average annual cumulative increase of pharmaceutical expenditure and potential savings generated by the future loss of patent coverage have been considered in order to identify the year of the Breakeven Point. Results : The economic effect induced by the progressive ageing of population produces an average of 0.94% cumulative increase in local pharmaceutical expenditure per year, corresponding to an incremental pharmaceutical expenditure of about € 116 millions per year. A number of 509 brands (103 active substances) will lose their patent coverage in the next 10 years. Considering both the present legislation and a level of price reduction, after patent expiration, corresponding to 40%, it is predicted that the Breakeven Point will be achieved at the end of 2011. Conclusions : In this study, a long term balance between the predictable increase of pharmaceutical expenditure induced by the ageing of Italian population and savings produced by future off-patent drugs was not established. In order to assure the future sustainability of pharmaceutical expenditure, this study supports the need for the development of new health policy strategies.

Effetto dei fabbisogni terapeutici sesso ed età correlati sui costi di prescrizione nella medicina generale

SummaryBackgroundThe primary objective of this study was to derive cost comparators for the fourteen Anatomical Therapeutic Chemical (ATC) classes of drugs at first level, based on age-sex related weightings. Our aim was to develop an accurate analysis method of prescribing patterns in general practice and to be able to explain individual variations in prescribing costs based on the age/sex distribution of the population and individual clinical needs.MethodsIndividual cost data were collected for 3,175,691 subjects living in three different Italian regions (Lombardy, situated in the North, Marche in the Centre and Basilicata in the South). The observation period was 12 months (September 2004–August 2005).ResultsThe analysis by ATC classes showed large variations in prescribing costs for the different age groups in each of the ATC classes for both sexes, and, in some instances, wide differences in prescribing costs by gender. The largest cost difference between age groups, for both males and females, was seen in drugs for the cardiovascular system. Antibiotics revealed a difference from the general pattern with more prescriptions in the youngest age groups compared to other ATC classes. Large differences between sexes were observed in the older age groups in drugs used for the respiratory system. The ASSET sample was a robust proxy of the actual public spending by ATC, while the therapeutic group age/sex related weightings were unable to explain the large individual variations in individual prescribing costs.ConclusionThe outcomes of this study are apparently discordant with the conclusions of the limited published literature on prescribing analysis in general practice, suggesting that the ability to make more accurate comparisons of prescribing rates, especially in individual therapeutic groups, should help to provide a more sensitive measure when estimating prescribing costs. The ASSET model confirmed the validity of demographic adjusted models to quantify the impact of ageing population in terms of resources needed to satisfy long term population prescribing needs. The ASSET age/sex weightings of total prescribing costs should be used as a guide, not as the ultimate determinant, for an equitable allocation of prescribing resources in conjunction with historic utilisation and cost data.

Effect of Age and Sex Related Therapeutic Needs on General Practices' Prescribing Cost: The ASSET (Age/Sex Standardised Estimates of Treatment) Research Model

The primary objective of this study was to derive cost comparators for the fourteen Anatomical Therapeutic Chemical (ATC) classes of drugs at first level, based on age-sex related weightings. It was hoped to develop an accurate method of analysing prescribing patterns in general practice and to be able to explain individual variations in prescribing cost based on the age/sex distribution of the population and individual clinical needs. Individual cost data were collected for 3,175,691 subjects living in three different regions of Italy (Lombardy, situated in the north, Marche in the centre and Basilicata in the south). The observation period was 12 months (September 2004 - August 2005).The analysis by ATC class showed large variations in prescribing costs for the different age groups in each of the ATC classes for both sexes, and, in some instances, wide differences in prescribing costs by sexes. The largest cost difference between age groups, for both males and females occurred in drugs used for the cardiovascular system. Antibiotics revealed a difference from the general pattern with more prescribing occurring in the youngest age groups compared to other ATC classes. Large differences between the sexes were observed in the older age groups in drugs used for the respiratory system.The ASSET model was a robust proxy of the actual public spending by ATC, while the therapeutic group age/sex related weightings were unable to explain the large individual variations in individual prescribing costs.The ASSET model confirmed the validity of demographic adjusted models to quantify the impact of ageing population in terms of resources needed to satisfy long term population prescribing needs. The ASSET age/sex weightings of total prescribing costs should be used as a guide, not as the ultimate determinant, for an equitable allocation of prescribing resources in conjunction with historic utilisation and cost data.

Knowledge-Based Governance Can Improve the Elderly Population's Equity of Access to Public Pharmaceutical Funding: The ASSET (Age/Sex Standardised Estimates of Treatment) Research Model

Ageing and technological change play a major role in the governance of healthcare resources, with cohorts living longer and consuming increasing amounts of intensive, previously unavailable treatments. Equity of access to pharmaceutical treatment on the basis of clinical need alone remains the central principle of the public healthcare system, raising the issue of an equitable distribution of resources in proportion to the population needs. The primary objective of this study was to discuss the adoption of a knowledge-based capitation model (ASSET, Age/Sex Standardised Estimates of Treatment) and its implications for healthcare policy makers. The ASSET model confirmed the validity of demographic adjusted models to quantify the impact of ageing population in terms of resources needed to satisfy long-term population prescribing needs. The ASSET weightings should be used as a guide, not as the ultimate determinant, for an equitable allocation of prescribing resources in conjunction with historic utilisation and cost data.