Population ageing has led to an increase in the prevalence of chronic diseases and in the use of health resources including medication. People over 65 years, which have a high prevalence of chronic diseases and are often treated with multiple drugs,1 represent 17% of the current Spanish population and are responsible of 70% of pharmaceutical expenditure.2 Moreover, in the last years, pharmaceutical expenditure has growth much more than the gross domestic product in most European countries, threatening the sustainability of public health care systems.3 On the other hand, potentially inappropriate prescribing (PIP) comprises a number of suboptimal prescribing practices, including inappropriate dose or duration of medication, drug-drug interactions, drug-disease interactions, and use of medications that have a significant risk of an adverse drug event.4,5 PIP has been found to be frequent in elderly population and associated with morbidity, adverse drug events, hospitalizations, and health care expenditures.6,7 For this reason, strategies aimed to improve the quality and safety of prescription in the elderly population can generate substantial health and economic benefits.8,9 Several criteria and algorithms have been developed to reduce PIP. One of the most used criteria is the Screening Tool of Older Persons Prescriptions/Screening Tool to Alert doctors to Right Treatment (STOPP/START).10 Likewise, an algorithm used to enable more rational and appropriate use of medication in elderly people is the Good Palliative-Geriatric Practice (GP-GP).11 Some authors have assessed the safety and effectiveness of interventions using these tools. Improvements in drug appropriateness and reduction in number of medications have been reported.12,13 Additionally, strategies including a clinical pharmacist can help decrease PIP and optimize patient therapy, resulting in better clinical outcomes.14 However, limited evidence exists about economic evaluations of these interventions.15,16 The objective of the present study was to assess the economic impact in drug expenditure of a pharmacist intervention on prescriptions to community-dwelling polymedicated elderly people.

After excluding patients who died (n=13), 245 patients were recruited to control group (78.7 years, SD: 5.5; 57.9% women) and 245 to intervention group (79.1 years, SD: 5.4; 61.6% women). No statistically significant differences were observed between the two groups in the number of drug prescriptions and drug expenditure during the 12 months before pharmacist intervention, indicating that both groups were originally comparable. We observed, however, statistically significant differences in drug expenditure and in the number of prescriptions during the 12 months after intervention. As shown in Table 1, although both groups experienced a decrease in drug expenditure 12 months after the study started, this decrease was significantly higher in the intervention group than in the control group. Similarly, the rise in generic drug prescriptions was significantly greater in the intervention group. Table 1 also reports on total cost and total number of prescriptions before and after the pharmacist intervention. It shows a significant reduction for both groups in total costs, in the total number of prescriptions, and a significant increase in both groups in the percentage of generic drugs prescribed. We also observed a significant increase in the number of new drug prescribed in the control group. Total annual drug expenditure in the intervention group decreased from 317,520.00 € (pre-intervention) to 260,263.00 € (post-intervention), representing 233.75 € (95% confidence interval [95%CI]: 169.83-297.67) saved per patient (1,296.00 €/patient pre vs. 1,062.30 €/patient post). Similarly, total annual drug expenditure in the control group decreased from 338,271.00 € to 296,768.00 €, which results in 169.40 € (95%CI: 103.37-235.43) saved per patient over one-year period (1,380.70 €/patient pre vs. 1,211.30 €/patient post). The resulting incremental drug expenditure of standard care over pharmacist intervention is 64.30 € per patient each year. In other words, 64.30 € would be the cost savings per patient a year attributable to the study intervention.

Figures 1 and 2 displays the monthly evolution of median drug expenditure and median number of prescriptions during 12 months pre-intervention and 12 months post-intervention for both groups. Further, the higher percentage of generic drugs prescribed in the intervention group remained largely unchanged throughout the one-year follow-up (Fig. 3). Finally, as regard the prescription of new drugs (Fig. 4), it is the standard care group that shows a rather more ascendant pattern, particularly over the last 4 months in the study.

Figure 1.

Evolution of median of drug expenditure (€) per patient 12 months before and 12 months after the intervention.

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Figure 2.

Evolution of median of prescriptions per patient 12 months before and 12 months after the intervention.

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Figure 3.

Evolution of percentage of generic drugs per patient 12 months before and 12 months after the intervention.

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Figure 4.

Evolution of percentage of new drugs per patient 12 months before and 12 months after the intervention.

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Table 2 presents the additional costs and savings under three scenarios. The average annual saving resulting from the study intervention is 37.57 € per patient a year. According to the sensitivity analysis performed, annual savings per patient range from 45.68 € (optimistic scenario) to 26.75 € per patient (conservative scenario). If we were to estimate the return on investment of the study intervention, dividing cost savings (64.30 €) by annual cost of intervention for each scenario, we would argue that for 1 € invested in the program we would be saving an average of 2.38 € per patient a year (ranging from 1.70 € to 3.40 €).

Our study reveals that a one-time pharmacist intervention in primary care allows for a 12 months accumulated reduction in total drug prescription and expenditure in community-dwelling polymedicated elderly people. It also shows an increase in the number of prescribed generic drug and a reduction in the number of prescribed “new drugs”. Since savings in drug expenditure are greater than costs derived from the intervention, the pharmacist intervention can be a cost-effective alternative to standard of care rendering a positive return on investment (2.38 €) per euro.

Our results are consistent with other findings from previous studies evaluating the economic impact of pharmacist interventions. In a series of systematic reviews conducted for the American College of Clinical Pharmacy, the economic value of clinical pharmacist services was summarized and evaluated. The first review, conducted by Schumock et al.,19 evaluated articles published from 1996-2000. They concluded that for every $1 invested in clinical pharmacy services, $4 was achieved in reduced costs or other economic benefits. A review by Pérez et al.,20 that included articles published between 2001-2005, showed similar results. The most recent published review on the topic21 incorporated fewer number of studies, published between 2006-2010, and could not provide a benefit/cost ratio as previous reviews did. One important difference between our study and other published studies included in these reviews is that the latter focused more on specific clinical conditions. Brennan et al. demonstrated a return on investment ratio of 3:1 using an integrated pharmacy program to improve medication prescription and adherence rates in diabetes patients.22 Pharmaceutical interventions have also proven to be cost-effective in pathologies such HIV,23 depression24 or hypertension.25 Despite these pieces of evidence, there are very few studies that focused on the economic evaluation of a pharmacist intervention that aim at reducing potentially inappropriate prescriptions and at improving drug appropriateness in community-dwelling polymedicated elderly people. When published, such studies showed very modest savings regarding medication costs with no statistical significance.26

Monthly evolution of median cost, median prescriptions per patient and percentage of generic drugs showed a somewhat parallel evolution on control and intervention groups indicating that the initial gap between both groups generated by the pharmacist intervention had a long-lasting effect on both variables. This effect appears to be slightly diluted one year after the intervention, and perhaps indicates that another pharmaceutical intervention should be done as reinforcement. On the other hand, “new drugs” showed an increase in prescription over the last 4 months in the study, pointing to a greater penetration of new products as therapeutic options in this group.

Although a significant reduction in drug prescription and expenditures was observed resulting from the intervention, it is of relevance to report that the control group also experienced a significant reduction in drug expenditure itself during the follow-up study period. This fact can be partially attributed to the study design, which was an open-label randomized clinical trial with possible intervention-to-control contagion. The prescribing physicians who received recommendations from the pharmacist regarding patients in the intervention group also visited patients in the control group. Consequently, the control group have indirectly benefited from the intervention, possibly diluting the true effect of the intervention. Moreover, the decrease in drug prescription in the control group may also be explained by other measures put forward by the Catalan Health Service to control drug expenditure in the primary care setting and by other important state control measures such as the Royal Decree-Law 16/2012, which introduced the co-payment system for outpatient pharmaceutical services and the exclusion of more than 400 products from public funding.

The reduction in total drug expenditure is largely a consequence of a decrease in the number of drugs prescribed (drug discontinuations), which accounts for 9.2% of total initial prescriptions. In addition, dose adjustments accounted for 6.9% and drug substitutions for 3.1% of initial prescriptions17. The use of generic drugs had a limited impact in drug cost savings since the Spanish drug regulation does not allow for differences in publicly financed prices between generic and non-generic drugs. Finally, it should be noted that although the prescription of new drugs is only a small percentage of overall drug prescription, the control group shows a more than three-fold increase in this respect when compared to the intervention group. Given the very high price of these new drugs, small differences in prescription frequency may have a relevant economic impact.

Probably, the main strength of the study is its controlled and randomized experimental design. There are a number of advantages of performing economic studies as part of an on-going clinical trial.27 Among other benefits, it is argued that since economic evaluation largely depends upon the quality of the data generated, clinical trials are an efficient setting for economic analyses. Both the quality of the data and the greater control over potential sources of bias favor clinical trials. However, the literature also outlines some limitations, the most relevant to our study being the generalization of the economic impact of the intervention in real-world practice. To overcome this limitation, we have selected a comparator that represents the most realistic choice in real practice. Other study limitations include: a) the intervention-to-control contagion, which may dilute the effect of the intervention; b) the exclusion of deaths from the analysis, which may carry an underestimation of total drug expenditure but do not alter inter-group comparisons because of the balanced number of deaths between groups; and c) cost elements considered are only cost in drug consumption and direct costs in human resources (time invested was a theoretical estimation), therefore more economic impact studies and full economic evaluations are required.

In summary, the present study shows that the intervention of a clinical pharmacist in the primary care setting evaluating all medication in polymedicated community-dwelling elderly subjects is responsible for a reduction of approximately 7% in drug expenditure. Such a community intervention may be a cost saving alternative with a possible positive return on investment.

Miguel Ángel Negrín Hernández.

The corresponding author on behalf of the other authors guarantee the accuracy, transparency and honesty of the data and information contained in the study, that no relevant information has been omitted and that all discrepancies between authors have been adequately resolved and described.

L. Campins designed the study, contributed in the fieldwork and wrote the manuscript. M. Serra-Prat designed the study, performed the statistical analysis and wrote the manuscript. E. Palomera performed the statistical analysis and review the manuscript. I. Bolibar review the manuscript with important contribution in methodological aspects. M.A. Martínez, medical coordinator of the study, contributed in the fieldwork and review the manuscript. P. Gallo review the manuscript with important contribution in economic aspects.