Three essays in health economics: Using prescription data to explore questions on variation in medical care and population health
Lead Research Organisation:
University of Southampton
Department Name: School of Social Sciences
Abstract
Three research articles in health economics that explore empirical questions on the topics of variation in medical care and patients health following a large-scale shock, all approached by the analysis of prescription data from general practice.
Organisations
People |
ORCID iD |
| Matias Ortiz De Zarate Rodriguez (Student) |
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| ES/R501025/1 | 30/09/2017 | 29/09/2021 | |||
| 1952560 | Studentship | ES/R501025/1 | 30/09/2017 | 30/03/2021 | Matias Ortiz De Zarate Rodriguez |
| Description | The NHS in conjunction with institutions like NICE is interested in promoting cost-effective use of prescription drugs. To do this, it fosters generic prescribing, and issues Technology Appraisals and Clinical Guidelines, in which it assesses the cost- and clinical-effectiveness of each technology available for the treatment of the condition these documents address. If the health authority is right in their assessment and the choices it recommends do not imply any differences in terms of health outcomes of the treated patients, then any deviation is ultimately inefficient and it leads to additional prescribing spending at no additional marginal benefit. On the other hand, heterogeneous behavior at the practice level might be the consequence of different beliefs about the absolute effectiveness of the different treatment, clinical experience with the treatments, experience of side effects, tolerance, and several aspects of the treatment process that can only be revealed in actual clinical practice. Then, the difference in prescribing behavior can be justified if it provides a marginal benefit to treated patients. The Statin therapeutic market (drugs to treat cardiovascular and high-cholesterol related conditions) has experienced, the loss of patent protection of its two main molecules (i.e., atorvastatin and simvastatin) and their subsequent generic availability, and the introduction of two clinical guidelines and one technology appraisal. These events have shaped the evolution of the trends in drug use. The prescription decisions in this therapeutic area, reveals an average prescribing behavior that is consistent with the low-cost, generic- and guidance-based prescribing, yet at the GP practice levels, there is a substantial variation which departs from their recommendations. The main objectives of my research are first, to understand the factors that explain variation in the prescription choices made inside General Practices, and second, to asses the consequences of such variation on the health outcomes of patients, the cost of treatment implied to the NHS, and other outcomes of the treatment process. The context that we study is the drug treatment of cardiovascular and high-cholesterol related conditions, in which the Statins are the main medications, prescribed in primary care by General Practitioners. With regard to the first part of the research, the overall findings suggest that both demand- and supply-side factors explain little of the variation in prescription decision-making. In other words, observable characteristics of the practice and the initial risk profile of the patient, subject upon which the drug decision is made, at the moment drug treatment starts, do not explain much of the variation around the average behavior. Yet I find revealing patterns that could help understand drivers behind the observed heterogeneity in initial prescription decisions made by GP practices for the treatment of high cholesterol and cardiovascular disorders. In particular, we find a role for Quality (Quality Outcomes Framework total points), demand size (number of new patients treated by each practice), and average years of professional experience as practitioners. The results suggest that practices with greater total QOF points, and with higher demand for new prescriptions, tend to exhibit a more cost-effective behavior. The results also suggest that practices with a cohort of practitioners with greater years of professional experience as GPs are more reluctant to change their prescribing behavior based solely on changes in acquisition cost; yet when a clinical guideline is introduced, the reaction of these practices favors the suggestion explicit in the document. On the other hand, we find that that drug treatment allocation is dependent on the initial characteristics of the patients when treatment starts. An important result suggests that the initial cardiovascular status affects the probability that a patient will be prescribed a given treatment. In particular, we find that patients treated for CVD secondary prevention (that is, those patients that initiate treatment with evidence of a CVD, and therefore riskier patients) are more likely to be prescribed the branded more expensive drug alternative, even when the current guideline suggest that this type of patients should be treated with the generic alternative. This reveals that the more expensive drug was perceived as a more appropriate (potent or effective) one to treat this kind of riskier patients. In the second part of this research, we ask whether the different prescribing behavior at the GP practice level is related to health outcomes. In order to test for this, we characterize each GP practice in every period in terms of their compliance with generic- and guidance-based prescribing. The outcomes that we study are the development of an adverse event within the first, second and third year of drug treatment; the cost of drug treatment implied to the NHS, and also the intensity of treatment (number of doses), and the probability that the firs-line of treatment is switched during the first three years of treatment. Our results suggest that differences in prescribing decision-making at the GP practice level do not imply any differences in the health outcomes of patients. This result is in line with a claim made in Technology Appraisal 94 in which NICE, in lgth of the available evidence by 2006 on the effectiveness of Statins concluded that none of them was superior in reducing the probability that a patient, on treatment, experienced a cardiovascular event. On the other hand and not surprisingly differences in compliance do affect the cost of treatment to the NHS. That is a practice that further deviates from the recommended standard imply greater cost to the NHS and in the light of the previous results, at no extra benefit. No significant effect is found with respect to how intensely patients are treated; that is, patients treated by practices that comply less do not receive a different number of doses than those that comply more. Finally, I found that practice that complies less to the recommendations set by NICE are significantly more likely to switch the first-line of treatment for their patients within the first three years of treatment. And the drug to which they switch is the one suggested by the health authority. Then, this reveals less compliant practices although they do not display a contemporaneous efficient prescribing behavior, they do show it later on, as they will later choose to switch their patients to the drug recommended by the health authority. |
| Exploitation Route | The outcomes of this research may inform health policymakers and institutions about the sources behind inefficient prescribing decision-making that takes place in the primary care setting. Considering that we only study the case of the Statins, drugs used to treat the leading cause of death in England, the results could help these institutions to promote and diffuse the content and suggestion stated in documents such as clinical guideline to those practice with certain characteristics that, as we found, might be associated to prescribing behavior that is less efficient, that is, that implies greater spending to the NHS, at no clear additional benefit to the patient. |
| Sectors | Communities and Social Services/Policy Healthcare Pharmaceuticals and Medical Biotechnology |