A system dynamics model for national drug policy

Optimal control strategies supported by system dynamics modelling: a study on hookworm disease in China

BACKGROUND

Hookworm disease remains a global health issue. In China, it persists with a 0.67% infection rate and uneven distribution in 2021. Optimized control strategies are needed. This study aims to optimize intervention strategies for hookworm disease in China.

METHODS

Structural analysis and parameter estimation were conducted using system dynamics theory. Key variables were identified via the Delphi method, leading to the creation of a causal loop diagram (CLD) and stock flow chart (SFC). Based on the SFC, parameter estimation and quantitative relationships were established and the model was validated. A cost-effectiveness model was then integrated into the intervention mechanism model. Various intervention measures were tested in the model to determine their cost-effectiveness ratio (CER) and effectiveness. Generalized linear models were constructed from simulation data, accounting for the impact of survey sites. The results were used to develop an optimized strategy for hookworm disease control.

RESULTS

In comparing drug treatment methods, whole population deworming (WPD) and key population deworming (KPD) showed lower CERs than examination and voluntarily deworming (EVD), saving 384.79-504.64 CNY and 354.35-506.21 CNY per infection reduced, respectively (P < 0.001). For WPD or KPD alone, CER decreased with increased drug coverage. For examination and deworming (ED) and EVD, CER was highest at 30% coverage for a 1-year intervention, but at 90% coverage for 2-5 years (P < 0.05). WPD, ED, and EVD had higher infection reduction rates than KPD, with ratios of 0.14-0.25, 0.10-0.19, and 0.08-0.17, respectively, over 1-5 years (P < 0.001). Continuous health education over 1-5 years showed that increasing coverage from a 10% baseline led to enhancing cost-effectiveness and intervention outcomes.

CONCLUSIONS

In high-endemic areas (infection rate ≥ 20%) in China, prioritize WPD for better cost-effectiveness and outcomes. In medium-endemic areas (5% ≤ infection rate < 20%) where WPD isn't feasible, use ED for cost-effectiveness and KPD for infection reduction, based on local needs. In low-endemic areas (infection rate < 5%), encourage voluntary examination and treatment due to limited cost-effectiveness of mass treatment. Combining drug treatment with extensive health education can enhance long-term control effect. This strategy can guide control efforts for hookworm diseases in China.

CLINICAL TRIAL NUMBER

Not applicable.

Access to essential medicines used in the management of noncommunicable diseases in Southern Ethiopia: Analysis using WHO/HAI methodology

Objectives

This study aims to assess access to essential medicines used in the management of noncommunicable diseases through analysis of the availability, prices, and affordability of these essential medicines in Arba Minch town, Gamo Zone, Southern Ethiopia.

Methods

A cross-sectional design was carried out using the World Health Organization/health action international methodology between 2 March and 2 May 2023, within public and private healthcare facilities located in Arba Minch town, Southern Ethiopia. The median price ratio served as a metric. Statistical tests like the Shapiro-Wilk and Kolmogorov-Smirnov were utilized to assess the normal distribution of price data. The Wilcoxon-Mann-Whitney U test was also employed to compare median buyer's prices (patient prices) between public and private healthcare institutions. Treatment affordability was determined by estimating the number of days' wages required by the lowest-paid government employee in Ethiopia to afford the prescribed medication regimen.

Results

Among 23 health facilities surveyed, the pooled availability of essential medicine used in the management of noncommunicable diseases was 18.7% (range: 0%-30.1%), with the public and private facilities contributing 16.3% and 38.3%, respectively. The overall percentage of availability originator brand versions was 1.1% for overall health sectors, 0.6% for public sectors, and 1.2% for private sectors. The overall percent availability of lowest price generics was 36.2% (range: 0%-26.2%; public: 32.0%; private: 37.1%). Only seven lowest price generics satisfied the World Health Organization target of 80% and above. The overall median price of lowest price generic medicines in private was two times higher than in public sectors. The top five median price scorers were amlodipine, furosemide, insulin, beclomethasone, and salbutamol. The Mann-Whitney U test showed that 11.6% of lowest price generics medicines had a statistically significant median price disparity between the public and private sectors (p < 0.05). The overall percent of unaffordability was found to be 100.0%, (public: 70.4; private: 100.0%).

Conclusions

This study revealed the limited availability and potential financial burdens on patients seeking essential noncommunicable disease medications. Limited availability suggests the need for better supply chain management and consistent stock availability. The price disparities and affordability challenges identified underscore the necessity for policy interventions such as price regulation and subsidized programs to ensure equitable access to essential noncommunicable disease medications in Arba Minch town, Southern Ethiopia.

Systems Thinking and Complexity Science Methods and the Policy Process in Non-communicable Disease Prevention: A Systematic Scoping Review

BACKGROUND

Given the complex determinants of non-communicable diseases (NCDs), and the dynamic policy landscape, researchers and policymakers are exploring the use of systems thinking and complexity science (STCS) in developing effective policies. The aim of this review is to systematically identify and analyse existing applications of STCS-informed methods in NCD prevention policy.

METHODS

Systematic scoping review: We searched academic databases (Medline, Scopus, Web of Science, EMBASE) for all publications indexed by 13 October 2020, screening titles, abstracts and full texts and extracting data according to published guidelines. We summarised key data from each study, mapping applications of methods informed by STCS to policy process domains. We conducted a thematic analysis to identify advantages, limitations, barriers and facilitators to using STCS.

RESULTS

4681 papers were screened and 112 papers were included in this review. The most common policy areas were tobacco control, obesity prevention and physical activity promotion. Methods applied included system dynamics modelling, agent-based modelling and concept mapping. Advantages included supporting evidence-informed decision-making; modelling complex systems and addressing multi-sectoral problems. Limitations included the abstraction of reality by STCS methods, despite aims of encompassing greater complexity. Challenges included resource-intensiveness; lack of stakeholder trust in models; and results that were too complex to be comprehensible to stakeholders. Ensuring stakeholder ownership and presenting findings in a user-friendly way facilitated STCS use.

CONCLUSION

This review maps the proliferating applications of STCS methods in NCD prevention policy. STCS methods have the potential to generate tailored and dynamic evidence, adding robustness to evidence-informed policymaking, but must be accessible to policy stakeholders and have strong stakeholder ownership to build consensus and change stakeholder perspectives. Evaluations of whether, and under what circumstances, STCS methods lead to more effective policies compared to conventional methods are lacking, and would enable more targeted and constructive use of these methods.

Factors Affecting the Product Life Cycle of Generic Medicines

Background

Product life cycle (PLC) refers to the time ranging from when a product is introduced into the market to when it is taken off the shelves. The PLC management can guarantee product survival and prevent its decline.

Objectives

This study investigated generic antibiotic PLCs and detected factors affecting them in the competitive pharmaceutical market of Iran to improve the PLC management of such drugs.

Methods

To study the PLC of antibiotics, data were collected from 2002 to 2017, and then the PLC curves were analyzed. Accordingly, factors affecting the PLC of antibiotics were illustrated in two sections: all PLC curves and the PLC curves with one sales peak. Using a generalized linear model combined with a machine learning approach, we identified the sales patterns and the effect of the product-related and the competition-related factors on the PLC curves, peak height, and the time to reach peak sales.

Results

According to the findings, 16, 11.87, 13.03, and 59% of the antibiotics had linear, binomial, one-peak, and oscillating sales patterns, respectively. The most crucial factors affecting the PLC shape were the quality, microbial spectrum, dosage forms, number of competitors, and entry arrangement.

Conclusions

This study examined factors affecting the PLC patterns of generic pharmaceutical products. The findings would provide more insights into the generic pharmaceutical market as one of the less-studied markets in many countries.

Main Factors Leading to Supplier-Induced Demand in Iran: A Comprehensive Review

Context: Supplier-induced demand (SID) is one of the challenges of health systems, leading to unbearable expenses, particularly for people. Objectives: The present study aimed to investigate the factors leading to SID in Iran. Data Sources: The present study is a comprehensive systematic review focusing on studies of SID up to the end of May 2018 in six English databases, five Persian databases, and two search engines. The exclusion criteria were publications in languages other than Persian and English and publications after May 2018. Data Extraction: A data extraction form was used to record authors' names and specifications, year of publication, the city of the study, language, purpose, methodology, data collection method, and factors influencing the induced demand. The risk of bias was assessed using a standard risk of bias tool. Results: We found 514 papers. Eventually, 16 papers met the inclusion criteria, and they were selected for the study. We found 11 papers in the Persian language and five articles in English. The design of 37.5% of the articles was qualitative, 31.25% analytical, 25% descriptive-analytical, and 6.25% descriptive. Factors influencing SID were classified at four levels including meta-level (Ministry of Health and Medical Education (MoHME)), macro-level (universities of Medical Sciences), meso-level (service providers), and micro-level (patients). Conclusions: According to the results of this research, creating SID can lead to serious challenges for health systems, service providers, patients, and insurance organizations. Therefore, health managers and policymakers need to design appropriate strategies such as adopting the evidence-based approach to purchasing services by the insurer and approval of standards and rules to reduce such SID.

Applying a health system perspective to the evolving Farmácia Popular medicines access programme in Brazil

The Farmácia Popular Program (FPP) launched a subsidy system in Brazil, but in coexistence with the ongoing regular governmental access to medicines (Unified Health System (SUS) dispensings) mechanisms, causing overlaps in terms of financing and target population. This characteristic is quite different from most countries with medicines cost-sharing schemes. This paper aims to analyse the FPP under a health systems perspective considering the different health system levels. We analysed the findings from the study ‘Impact of consecutive subsidies policies on access to and use of medicines in Brazil – ISAUM-Br’, designed with the objective of describing and evaluating the impact of the government medicines subsidy policies implemented between 2004 and 2011. Patient share of copayment increased with the implementation of the intervention, which decreased the reference price and decreased with SNP (Saúde Não Tem Preço; zero copayment for patients). There was an increased number of FPP dispensations over time, but SUS dispensings remained the most important source for medicines, especially for hypertension and diabetes. FPP allowed the establishment of a well-designed pharmaceutical information system in the country. Despite the improvement on control mechanism, fraud remained a problem. There were important effects on the pharmaceutical market and sales of generic medicines. FPP has proven to be a very important policy for promoting access to medicines for hypertension and diabetes in Brazil. Examining this policy with a health system perspective has allowed us to highlight many of its important consequences, including for the first time a broad and consistent information system on access to medicines in the country.

Development of MY-DRG casemix pharmacy service weights in UKM Medical Centre in Malaysia

BACKGROUND

The service weight is among several issues and challenges in the implementation of case-mix in developing countries, including Malaysia. The aim of this study is to develop the Malaysian Diagnosis Related Group (MY-DRG) case-mix pharmacy service weight in University Kebangsaan Malaysia-Medical Center (UKMMC) by identifying the actual cost of pharmacy services by MY-DRG groups in the hospital.

METHODS

All patients admitted to UKMMC in 2011 were recruited in this study. Combination of Step-down and Bottom-up costing methodology has been used in this study. The drug and supplies cost; the cost of staff; the overhead cost; and the equipment cost make up the four components of pharmacy. Direct costing approach has been employed to calculate Drugs and supplies cost from electronic-prescription system; and the inpatient pharmacy staff cost, while the overhead cost and the pharmacy equipments cost have been calculated indirectly from MY-DRG data base. The total pharmacy cost was obtained by summing the four pharmacy components' cost per each MY-DRG. The Pharmacy service weight of a MY-DRG was estimated by dividing the average pharmacy cost of the investigated MY-DRG on the average of a specified MY-DRG (which usually the average pharmacy cost of all MY-DRGs).

RESULTS

Drugs and supplies were the main component (86.0%) of pharmacy cost compared o overhead cost centers (7.3%), staff cost (6.5%) and pharmacy equipments (0.2%) respectively. Out of 789 inpatient MY-DRGs case-mix groups, 450 (57.0%) groups were utilized by the UKMMC. Pharmacy service weight has been calculated for each of these 450 MY-DRGs groups. MY-DRG case-mix group of Lymphoma & Chronic Leukemia group with severity level three (C-4-11-III) has the highest pharmacy service weight of 11.8 equivalents to average pharmacy cost of RM 5383.90. While the MY-DRG case-mix group for Circumcision with severity level one (V-1-15-I) has the lowest pharmacy service weight of 0.04 equivalents to average pharmacy cost of RM 17.83.

CONCLUSION

A mixed approach which is based partly on top-down and partly on bottom up costing methodology has been recruited to develop MY-DRG case-mix pharmacy service weight for 450 groups utilized by the UKMMC in 2011.