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Hsu JC, Ross-Degnan D, Wagner AK, Zhang F, Lu CY. How Did Multiple FDA Actions Affect the Utilization and Reimbursed Costs of Thiazolidinediones in US Medicaid? Clin Ther 2015; 37:1420-1432.e1. [PMID: 25976425 PMCID: PMC5201140 DOI: 10.1016/j.clinthera.2015.04.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 03/16/2015] [Accepted: 04/08/2015] [Indexed: 12/22/2022]
Abstract
PURPOSE The US Food and Drug Administration (FDA) communicated the potential cardiovascular risk of thiazolidinediones (rosiglitazone and pioglitazone) in 2007 and required a Risk Evaluation and Mitigation Strategy (REMS) for rosiglitazone in 2010. It also communicated in 2010 the potential risk of bladder cancer with pioglitazone use. This study examined the effects of these multiple FDA actions on utilization and reimbursed costs of thiazolidinediones in state Medicaid programs. METHODS State Drug Utilization Data from the Centers for Medicare & Medicaid Services were assessed. An interrupted time series design and segmented linear regression models were used to examine changes in market shares according to both prescription volume and reimbursed costs for rosiglitazone and pioglitazone in the Northeast and Midwest regions of the United States after multiple FDA actions. FINDINGS Compared with expected rates, there were relative reductions of 65.84% (Northeast region) and 55.09% (Midwest region) in the use of rosiglitazone at 1 year after the 2007 FDA actions for thiazolidinediones and cardiac risk. At the same time, relative increases of 7.30% and 9.28% in the use of pioglitazone were observed in the Northeast and Midwest regions, respectively. Changes in both use and costs of rosiglitazone after the 2010 REMS program could not be estimated because of the already low rates (~1%) before REMS was implemented. One year after the 2010 FDA actions for pioglitazone and its possible association with bladder cancer, relative reductions in pioglitazone use of 21.41% (Northeast region) and 18.12% (Midwest region) were detected. IMPLICATIONS The Northeast and Midwest regions reported similar patterns of changes after the FDA actions. Use and costs of rosiglitazone were substantially reduced after the 2007 FDA actions for cardiovascular risk, and this drug was rarely used after the 2010 REMS program. Conversely, use and costs of pioglitazone were substantially reduced after the 2010 FDA actions regarding the drug's possible risk of bladder cancer.
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Hsu JC, Ross-Degnan D, Wagner AK, Cheng CL, Yang YHK, Zhang F, Lu CY. Utilization of oral antidiabetic medications in Taiwan following strategies to promote access to medicines for chronic diseases in community pharmacies. J Pharm Policy Pract 2015; 8:15. [PMID: 25949816 PMCID: PMC4422418 DOI: 10.1186/s40545-015-0035-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 04/01/2015] [Indexed: 12/03/2022] Open
Abstract
Objectives Taiwan’s National Health Insurance (NHI) has encouraged physicians to use “chronic medication prescriptions” for patients with stable chronic diseases since 1995. Patients are allowed to refill such prescriptions at community pharmacies for a maximum of three months’ supply of medications without revisiting the doctor. In 2006, NHI initiated strategies targeting the public, doctors, and healthcare facilities to enhance the overall rate of chronic medication prescriptions, aiming to achieve 30% by 2010. We examined prescribing and dispensing of oral antidiabetic drugs from 2001 to 2010, before and after the start of the promotion strategies for chronic medication prescriptions in 2006. Methods Using outpatient care data from the NHI database and the interrupted time series design, we analyzed changes in rate of chronic medication prescriptions, share of prescriptions filled at community pharmacies, and share of reimbursed expenditures accounted by community pharmacies. Results During 2001-2010, the rate of chronic medication prescriptions for diabetes increased steadily by about 3% per year (from 3.5% to 26.2%). Three years after the promotion strategies, there was a non-significant reduction of 8.7% (95% confidence interval [CI]: -17.35%, 0.05%) in the rate of chronic medication prescriptions but increases in prescription refills at community pharmacies and associated reimbursed expenditures: 12.8% (95% C.I.:1.66%, 23.98%) and 15.8% (95% C.I.: -1.35%, 33.02%) respectively. Conclusions While rate of chronic medication prescriptions was not significantly affected by the 2006 promotion strategy, shares of prescriptions refilled at community pharmacies and associated expenditures increased slightly but significantly.
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Sruamsiri R, Ross-Degnan D, Lu CY, Chaiyakunapruk N, Wagner AK. Policies and programs to facilitate access to targeted cancer therapies in Thailand. PLoS One 2015; 10:e0119945. [PMID: 25798948 PMCID: PMC4370712 DOI: 10.1371/journal.pone.0119945] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Accepted: 01/26/2015] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Increasing access to clinically beneficial targeted cancer medicines is a challenge in every country due to their high cost. We describe the interplay of innovative policies and programs involving multiple stakeholders to facilitate access to these medicines in Thailand, as well as the utilization of selected targeted therapies over time. METHODS We selected two medicines on the 2013 Thai national list of essential medicines (NLEM) [letrozole and imatinib] and three unlisted medicines for the same indications [trastuzumab, nilotinib and dasatinib]. We created timelines of access policies and programs for these products based on scientific and grey literature. Using IMS Health sales data, we described the trajectories of sales volumes of the study medicines between January 2001 and December 2012. We compared estimated average numbers of patients treated before and after the implementation of policies and programs for each product. RESULTS Different stakeholders implemented multiple interventions to increase access to the study medicines for different patient populations. During 2007-2009, the Thai Government created a special NLEM category with different coverage requirements for payers and issued compulsory licenses; payers negotiated prices with manufacturers and engaged in pooled procurement; pharmaceutical companies expanded patient assistance programs and lowered prices in different ways. Compared to before the interventions, estimated numbers of patients treated with each medicine increased significantly afterwards: for letrozole from 645 (95% CI 366-923) to 3683 (95% CI 2,748-4,618); for imatinib from 103 (95% CI 72-174) to 350 (95% CI 307-398); and for trastuzumab from 68 (95% CI 45-118) to 412 (95% CI 344-563). CONCLUSIONS Government, payers, and manufacturers implemented multi-pronged approaches to facilitate access to targeted cancer therapies for the Thai population, which differed by medicine. Routine monitoring is needed to assess clinical and economic impacts of these strategies in the health system.
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Kumar RG, Diamond ML, Boles JA, Berger RP, Tisherman SA, Kochanek PM, Wagner AK. Acute CSF interleukin-6 trajectories after TBI: associations with neuroinflammation, polytrauma, and outcome. Brain Behav Immun 2015; 45:253-62. [PMID: 25555531 DOI: 10.1016/j.bbi.2014.12.021] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 12/08/2014] [Accepted: 12/21/2014] [Indexed: 12/12/2022] Open
Abstract
Traumatic brain injury (TBI) results in a significant inflammatory burden that perpetuates the production of inflammatory mediators and biomarkers. Interleukin-6 (IL-6) is a pro-inflammatory cytokine known to be elevated after trauma, and a major contributor to the inflammatory response following TBI. Previous studies have investigated associations between IL-6 and outcome following TBI, but to date, studies have been inconsistent in their conclusions. We hypothesized that cohort heterogeneity, temporal inflammatory profiles, and concurrent inflammatory marker associations are critical to characterize when targeting subpopulations for anti-inflammatory therapies. Toward this objective, we used serial cerebrospinal fluid (CSF) samples to generate temporal acute IL-6 trajectory (TRAJ) profiles in a prospective cohort of adults with severe TBI (n=114). We examined the impact of injury type on IL-6 profiles, and how IL-6 profiles impact sub-acute (2weeks-3months) serum inflammatory marker load and long-term global outcome 6-12months post-injury. There were two distinct acute CSF IL-6 profiles, a high and low TRAJ group. Individuals in the high TRAJ had increased odds of unfavorable Glasgow Outcome Scale (GOS) scores at 6months (adjusted OR=3.436, 95% CI: 1.259, 9.380). Individuals in the high TRAJ also had higher mean acute CSF inflammatory load compared to individuals in the low TRAJ (p⩽0.05). The two groups did not differ with respect acute serum profiles; however, individuals in the high CSF IL-6 TRAJ also had higher mean sub-acute serum IL-1β and IL-6 levels compared with the low TRAJ group (p⩽0.05). Lastly, injury type (isolated TBI vs. TBI+polytrauma) was associated with IL-6 TRAJ group (χ(2)=5.31, p=0.02). Specifically, there was 70% concordance between those with TBI+polytrauma and the low TRAJ; in contrast, isolated TBI was similarly distributed between TRAJ groups. These data provide evidence that sustained, elevated levels of CSF IL-6 are associated with an increased inflammatory load, and these increases are associated with increased odds for unfavorable global outcomes in the first year following TBI. Future studies should explore additional factors contributing to IL-6 elevations, and therapies to mitigate its detrimental effects on outcome.
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Lu CY, Emmerick ICM, Stephens P, Ross-Degnan D, Wagner AK. Uptake of new antidiabetic medications in three emerging markets: a comparison between Brazil, China and Thailand. J Pharm Policy Pract 2015; 8:7. [PMID: 25815201 PMCID: PMC4343056 DOI: 10.1186/s40545-014-0020-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 12/10/2014] [Indexed: 11/22/2022] Open
Abstract
Objectives New antidiabetic medications such as insulin analogues and thiazolidinediones have been introduced over the last decade. This study compares the uptake of new agents in three emerging pharmaceutical markets: Brazil, China, and Thailand. Methods Using longitudinal IMS Health sales data, we calculated the quarterly percentage market share for types of insulins and oral hypoglycemic agents from 2002 through 2012 in each country. New oral hypoglycemic agents included: alpha-glucosidase inhibitors, thiazolidinediones, dipeptidyl peptidase-4 inhibitors, and non-sulfonylurea secretagogues. Results While China had the highest use of insulin cartridges and pens (85.6% in 2010), Brazil was the earliest adopter of insulin analogues and had the greatest use of these products overall (44.6% of the insulin market) in 2010, which then decreased by almost half by 2012. Together, sulfonylureas and metformin dominated the markets in Brazil and Thailand (~89% and ~96% respectively) over the 10-year period. Between 2002 and 2012, there was a shift in use from sulfonylureas to metformin; the market share of newer agents remained 10% or less in both countries. In China, however, market share of new oral agents grew rapidly from 13.1% to 44.4%. While metformin use was relatively stable in China (one-third of the market), sulfonylureas declined substantially over the 10-year period (41.5% to 20.8%). Conclusion Given large cost differentials between newer and older insulins and among oral hypoglycemic agents, it is important to evaluate uptake of newer products over time. Uptake patterns differed in the study countries, likely due to different medicines policy approaches. Future research should evaluate how trends in use of antidiabetic products align with national clinical practice guidelines and pharmaceutical policies, as well as the impacts of different patterns of use on cost and clinical outcomes.
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Lu CY, Lupton C, Rakowsky S, Babar ZUD, Ross-Degnan D, Wagner AK. Patient access schemes in Asia-pacific markets: current experience and future potential. J Pharm Policy Pract 2015; 8:6. [PMID: 25815200 PMCID: PMC4359387 DOI: 10.1186/s40545-014-0019-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 12/04/2014] [Indexed: 11/30/2022] Open
Abstract
Objectives Patient access (or risk-sharing) schemes are alternative market access agreements between healthcare payers and medical product manufacturers for conditional coverage of promising health technologies. This study aims to identify and characterize patient access schemes to date in the Asia-Pacific region. Methods We reviewed the literature on patient access schemes over the last two decades using publicly available databases, Internet, and grey literature searches. We extracted key features of each scheme identified, including the drug, clinical indication, stakeholders involved, and details of the scheme. We categorized schemes according to a previously published taxonomy of scheme types and by country. Results We identified 3 schemes in South Korea, 5 in New Zealand, and 98 in Australia. Most (97.2%; n = 103) schemes focused on pharmaceuticals, few on medical technologies. More than half of the schemes related to treatments for cancer and inflammatory diseases such as rheumatoid arthritis. The majority (77.4%; n =82) involved pricing arrangements. Evidence generation schemes were rarely used. About half (41.8%; n = 41) of schemes in Australia were hybrid by nature, consisting of pricing arrangements with a conditional treatment continuation component. Conclusions Australia has the most experience with patient access schemes and its experience may provide useful insights for other Asia-Pacific countries. The main targets are pharmaceuticals likely to have high budget impact (due to high per-patient costs and/or large volumes of use), and pharmaceuticals that may be adopted more widely than indicated. With the proliferation of high-cost medicines, the use of schemes may increase to address rising cost pressures, consumer demands, and uncertainties, while attempting to provide patient access to innovative care within finite budgets. Future research is warranted to evaluate the performance of patient access schemes.
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Juengst SB, Kumar RG, Arenth PM, Wagner AK. Exploratory associations with tumor necrosis factor-α, disinhibition and suicidal endorsement after traumatic brain injury. Brain Behav Immun 2014; 41:134-43. [PMID: 24928066 DOI: 10.1016/j.bbi.2014.05.020] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 05/01/2014] [Accepted: 05/08/2014] [Indexed: 12/22/2022] Open
Abstract
PURPOSE To examine the relationship of Tumor Necrosis Factor (TNF)-α to disinhibition and suicidal endorsement after traumatic brain injury (TBI). PARTICIPANTS Adults with moderate to severe TBI (acute serum levels: n=48, n=543 samples; acute CSF levels: n=37, n=389 samples; chronic serum levels: n=48, n=326 samples). MAIN MEASURES TNFα levels (CSF, Serum) from time of injury to 12 months post-injury; Frontal Systems Behavior Scale - Disinhibition Subscale at 6 and 12 months post-injury; Patient Health Questionnaire at 6 and 12 months post-injury. RESULTS Participants with TBI had significantly higher CSF and serum TNFα levels than healthy controls (p<0.05). Acute and chronic serum TNFα was significantly associated with disinhibition at 6 months post-injury (p=0.009, p=0.029 respectively), and 6 month disinhibition was associated with suicidal endorsement at both 6 and 12 months (p=0.045, p=0.033 respectively) and disinhibition at 12 months post-injury (p<0.001). CONCLUSION These preliminary data suggest a biological to behavioral pathway of suicidality after TBI, from TNFα to disinhibition to suicidal endorsement. Future investigation is warranted to validate these findings and clarify what biological mechanisms might underlie these relationships.
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Vialle-Valentin CE, Serumaga B, Wagner AK, Ross-Degnan D. Evidence on access to medicines for chronic diseases from household surveys in five low- and middle-income countries. Health Policy Plan 2014; 30:1044-52. [PMID: 25255920 DOI: 10.1093/heapol/czu107] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2014] [Indexed: 12/15/2022] Open
Abstract
The 2011 United Nations (UN) General Assembly Political Declaration on Prevention and Control of Non-Communicable Diseases (NCDs) brought NCDs to the global health agenda. Essential medicines are central to treating chronic diseases such as hypertension and diabetes. Our study aimed to quantify access to essential medicines for people with chronic conditions in five low- and middle-income countries and to evaluate how household socioeconomic status and perceptions about medicines availability and affordability influence access. We analysed data for 1867 individuals with chronic diseases from national surveys (Ghana, Jordan, Kenya, Philippines and Uganda) conducted in 2007-10 using a standard World Health Organization (WHO) methodology to measure medicines access and use. We defined individuals as having access to medicines if they reported regularly taking medicine for a diagnosed chronic disease and data collectors found a medicine indicated for that disease in their homes. We used logistic regression models accounting for the clustered survey design to investigate determinants of keeping medicines at home and predictors of access to medicines for chronic diseases. Less than half of individuals previously diagnosed with a chronic disease had access to medicines for their condition in every country, from 16% in Uganda to 49% in Jordan. Other than reporting a chronic disease, higher household socioeconomic level was the most significant predictor of having any medicines available at home. The likelihood of having access to medicines for chronic diseases was higher for those with medicines insurance coverage [highest adjusted odds ratio (OR) 3.12 (95% confidence intervals (CI): 1.38, 7.07)] and lower for those with past history of borrowing money to pay for medicines [lowest adjusted OR 0.56 (95% CI: 0.34, 0.92)]. Our study documents poor access to essential medicines for chronic conditions in five resource-constrained settings. It highlights the importance of financial risk protection and consumer education about generic medicines in global efforts towards improving treatment of chronic diseases.
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Wagner AK, Quick JD, Ross-Degnan D. Quality use of medicines within universal health coverage: challenges and opportunities. BMC Health Serv Res 2014; 14:357. [PMID: 25164588 PMCID: PMC4158132 DOI: 10.1186/1472-6963-14-357] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 08/20/2014] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Medicines are a major driver of quality, safety, equity, and cost of care in low and middle-income country health systems. Universal health coverage implementers must explicitly address appropriate use of medicines to realize the health benefits of medicines, avoid wasting scarce resources, and sustain the financial viability of universal health coverage schemes. DISCUSSION Medicines are major contributors to the health and well-being of individuals and populations when used appropriately, and they waste resources and endanger health when used unnecessarily or incorrectly. Stakeholders need to balance inherently competing objectives in the pharmaceutical sector. Emerging and expanding UHC schemes provide potential levers to balance competing system objectives.To use these levers, sustainable universal coverage programs will require a) information systems that can track medicines utilization, expenditures, and quality of medicines use; b) routine monitoring of indicators of medicines availability, access, affordability, and use; c) policies and programs that facilitate appropriate medicines use by prescribers, dispensers, and patients; d) transparency in setting priorities for medicines coverage under resource constraints; and e) a system perspective to engage diverse actors.As they operationalize paths toward universal health coverage and include targeted medicines coverage policies and programs, systems can build on, and innovate, pharmaceutical policy frameworks and management tools from different countries' settings. SUMMARY Ensuring that medicines which achieve important health outcomes are available, accessible to all, used appropriately, and sustainably affordable is essential for realizing universal health coverage. Stakeholder cooperation and use of information and financing system levers provide opportunities to work toward this goal.
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Leopold C, Mantel-Teeuwisse AK, Vogler S, Valkova S, de Joncheere K, Leufkens HGM, Wagner AK, Ross-Degnan D, Laing R. Effect of the economic recession on pharmaceutical policy and medicine sales in eight European countries. Bull World Health Organ 2014; 92:630-640D. [PMID: 25378754 PMCID: PMC4208566 DOI: 10.2471/blt.13.129114] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 02/11/2014] [Accepted: 03/20/2014] [Indexed: 11/27/2022] Open
Abstract
Objective To identify pharmaceutical policy changes during the economic recession in eight European countries and to determine whether policy measures resulted in lower sales of, and less expenditure on, pharmaceuticals. Methods Information on pharmaceutical policy changes between 2008 and 2011 in eight European countries was obtained from publications and pharmaceutical policy databases. Data on the volume and value of the quarterly sales of products between 2006 and 2011 in the 10 highest-selling therapeutic classes in each country were obtained from a pharmaceutical market research database. We compared these indicators in economically stable countries; Austria, Estonia and Finland, to those in economically less stable countries, Greece, Ireland, Portugal, Slovakia and Spain. Findings Economically stable countries implemented two to seven policy changes each, whereas less stable countries implemented 10 to 22 each. Of the 88 policy changes identified, 33 occurred in 2010 and 40 in 2011. They involved changing out-of-pocket payments for patients in 16 cases, price mark-up schemes in 13 and price cuts in 11. Sales volumes increased moderately in all countries except Greece and Portugal, which experienced slight declines after 2009. Sales values decreased in both groups of countries, but fell more in less stable countries. Conclusion Less economically stable countries implemented more pharmaceutical policy changes during the recession than economically stable countries. Unexpectedly, pharmaceutical sales volumes increased in almost all countries, whereas sales values declined, especially in less stable countries.
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Hsu JC, Lu CY, Wagner AK, Chan KA, Lai MS, Ross-Degnan D. Impacts of drug reimbursement reductions on utilization and expenditures of oral antidiabetic medications in Taiwan: an interrupted time series study. Health Policy 2013; 116:196-205. [PMID: 24314624 DOI: 10.1016/j.healthpol.2013.11.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 10/09/2013] [Accepted: 11/04/2013] [Indexed: 11/19/2022]
Abstract
OBJECTIVES To control increasing pharmaceutical expenditures, Taiwan's National Health Insurance has implemented a series of drug reimbursement price reductions since 2000. This study examined changes in use and expenditures of oral antidiabetic medications following the price regulation in November 2006. METHODS We obtained claims data between January 2006 and August 2007 from Taiwan's National Health Insurance Research Database. We categorized oral antidiabetic products as affected by the reimbursement reduction ("targeted") or not ("non-targeted"), by level of relative price reduction, and by manufacturer type (international vs. local manufacturers). We used an interrupted time series design and segmented regression models to estimate changes in monthly per capita prescribing rate, volume, and insurance reimbursement expenditures following the policy. RESULTS The majority (129/178; 72.5%) of oral antidiabetic products were targeted by this round of price reductions. There was a relative reduction of 9.5% [95%CI: -12.68, -6.32] in total expenditures at ten months post-policy compared to expected rates. For targeted products, there were 2.04% [95%CI: -4.15, 0.07] and 13.26% [95%CI: -16.64, -9.87] relative reductions in prescribing rate and expenditures, respectively, at ten months post-policy. Non-targeted products increased significantly (22% [95%CI: 10.49, 33.51] and 22.85% [95%CI: 11.69, 34.01] relative increases in prescribing rate and expenditures respectively). Larger reimbursement cuts led to greater reductions in prescribing rate, volume, and insurance reimbursement expenditures of targeted products. Prescribing rates of both targeted and non-targeted products by international manufacturers declined after the policy while rates of prescribing non-targeted products by local manufacturers increased. CONCLUSIONS While total government expenditures for oral antidiabetic medications were contained by the policy, our results indicate that prescribing shifted at the margin from targeted to non-targeted products and from international to local products. Further research is warranted to understand how changes in medication use due to price regulation policies affect medication adherence and patient health outcomes.
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Fang Y, Wagner AK, Yang S, Jiang M, Zhang F, Ross-Degnan D. Access to affordable medicines after health reform: evidence from two cross-sectional surveys in Shaanxi Province, western China. LANCET GLOBAL HEALTH 2013; 1:e227-37. [PMID: 25104348 DOI: 10.1016/s2214-109x(13)70072-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Limited access to essential medicines is a global problem. Improving availability and affordability of essential medicines is a key objective of the National Essential Medicine Policy (NEMP) in China. In its initial implementation in 2009, the NEMP targeted primary hospitals with policies designed to increase availability of essential medicines and reduce patients' economic burden from purchasing medicines. We assessed medicine availability and price during the early years of the health reform in Shaanxi Province in underdeveloped western China. METHODS We undertook two public (hospitals) and private (pharmacy) sector surveys of prices and availability of medicines, in September, 2010 and April, 2012, by a standard methodology developed by WHO and Health Action International. We measured medicine availability in outlets at the time of the surveys and inflation-adjusted median unit prices (MUPs), taking 2010 as the base year. We used general estimating equations to calculate the significance of differences in availability from 2010 to 2012 and the Wilcoxon signed rank test to calculate the significance of differences in adjusted median prices. FINDINGS We collected data from 50 public sector hospitals and 36 private sector retail pharmacies in 2010 and 72 public hospitals and 72 retail pharmacies in 2012. Mean availability of surveyed medicines was low in both the public and private sectors; availability of many essential medicines decreased from 2010 to 2012, particularly in primary hospitals (from 27·4% to 22·3% for lowest priced generics; p<0·0001). The MUPs of originator brands and their generic equivalents decreased significantly from 2010 to 2012 in primary hospitals in comparison with secondary and tertiary hospitals. In the public sector, the median adjusted patient price was significantly lower in 2012 than in 2010 for 16 originator brands (difference -11·7%; p=0·0019) and 29 lowest-priced generics (-5·2%; p=0·0015); the median government procurement price for originator brands also decreased significantly (-10·9%; p=0·0004), whereas the decrease in median procurement price for lowest-priced generics was not significant (-4·9%; p=0·17). In the private sector, the median percentage decrease in price between 2010 and 2012 for 38 lowest-priced generics was 4·7% (IQR 6·3-13·2), compared with 7·9% (4·9-13·9) for 16 originator brands. INTERPRETATION Although inflation-adjusted medicine prices were numerically lower, there were concerning decreases in availability of lowest-priced generic medicines in both the public and private sectors in 2012 from already low availability in 2010. A long-term, stable, and consistent information system is needed to monitor effects of further implementation of the Chinese Essential Medicine Policy. FUNDING The National Natural Science Fund (71103141/G0308), the China Medical Board Faculty Development Awards, the Fundamental Research Funds for the Central Universities (2011jdhz62), the Shaanxi Provincial Social Science Fund (10E066), and the Harvard Medical School Pharmaceutical Policy Research Fellowship.
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Chalker JC, Wagner AK, Tomson G, Johnson K, Wahlström R, Ross-Degnan D. Appointment systems are essential for improving chronic disease care in resource-poor settings: learning from experiences with HIV patients in Africa. Int Health 2013; 5:163-5. [PMID: 24030266 DOI: 10.1093/inthealth/iht013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Lessons learned from treating patients with HIV infection can inform care systems for other chronic conditions. For antiretroviral treatment, attending appointments on time correlates with medication adherence; however, HIV clinics in East Africa, where attendance rates vary widely, rarely include systems to schedule appointments or to track missed appointments or patient follow-up. An introduction of low-cost, paper-based patient appointment and tracking systems led to an improvement in timely clinic attendance rates and tracking missing patients. An effective appointment system is critical to managing patients with chronic conditions and can be introduced in resource-limited settings, possibly without having to add staff.
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Reddy SR, Ross-Degnan D, Zaslavsky AM, Soumerai SB, Wagner AK. Health care payments in the Asia Pacific: validation of five survey measures of economic burden. Int J Equity Health 2013; 12:49. [PMID: 23822552 PMCID: PMC3716807 DOI: 10.1186/1475-9276-12-49] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 06/10/2013] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION Many low and middle-income countries rely on out-of-pocket payments to help finance health care. These payments can pose financial hardships for households; valid measurement of this type of economic burden is therefore critical. This study examines the validity of five survey measures of economic burden caused by health care payments. METHODS We analyzed 2002/03 World Health Survey household-level data from four Asia Pacific countries to assess the construct validity of five measures of economic burden due to health care payments: any health expenditure, health expenditure amount, catastrophic health expenditure, indebtedness, and impoverishment. We used generalized linear models to assess the correlations between these measures and other constructs with which they have expected associations, such as health care need, wealth, and risk protection. RESULTS Measures of impoverishment and indebtedness most often correlated with health care need, wealth, and risk protection as expected. Having any health expenditure, a large health expenditure, or even a catastrophic health expenditure did not consistently predict degree of economic burden. CONCLUSIONS Studies that examine economic burden attributable to health care payments should include measures of impoverishment and indebtedness.
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Holloway KA, Ivanovska V, Wagner AK, Vialle-Valentin C, Ross-Degnan D. Have we improved use of medicines in developing and transitional countries and do we know how to? Two decades of evidence. Trop Med Int Health 2013; 18:656-64. [PMID: 23648177 DOI: 10.1111/tmi.12123] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To assess progress in improving use of medicines in developing and transitional countries by reviewing empirical evidence, 1990-2009, concerning patterns of primary care medicine use and intervention effects. METHODS We extracted data on medicines use, study setting, methodology and interventions from published and unpublished studies on primary care medicine use. We calculated the medians of six medicines use indicators by study year, country income level, geographic region, facility ownership and prescriber type. To estimate intervention impacts, we calculated greatest positive (GES) and median effect sizes (MES) from studies meeting accepted design criteria. RESULTS Our review comprises 900 studies conducted in 104 countries, reporting data on 1033 study groups from public (62%), and private (mostly for profit) facilities (26%), and households. The proportion of treatment according to standard treatment guidelines was 40% in public and <30% in private-for-profit sector facilities. Most indicators showed suboptimal use and little progress over time: Average number of medicines prescribed per patient increased from 2.1 to 2.8 and the percentage of patients receiving antibiotics from 45% to 54%. Of 405 (39%) studies reporting on interventions, 110 (27%) used adequate study design and were further analysed. Multicomponent interventions had larger effects than single component ones. Median GES was 40% for provider and consumer education with supervision, 17% for provider education alone and 8% for distribution of printed education materials alone. Median MES showed more modest improvements. CONCLUSIONS Inappropriate medicine use remains a serious global problem.
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Wagner AK, Graves AJ, Fan Z, Walker S, Zhang F, Ross-Degnan D. Need for and access to health care and medicines: are there gender inequities? PLoS One 2013; 8:e57228. [PMID: 23505420 PMCID: PMC3591435 DOI: 10.1371/journal.pone.0057228] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2012] [Accepted: 01/18/2013] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Differences between women and men in political and economic empowerment, education, and health risks are well-documented. Similar gender inequities in access to care and medicines have been hypothesized but evidence is lacking. METHODS We analyzed 2002 World Health Survey data for 257,922 adult respondents and 80,932 children less than 5 years old from 53 mostly low and middle-income countries. We constructed indicators of need for, access to, and perceptions of care, and we described the number of countries with equal and statistically different proportions of women and men for each indicator. Using multivariate logistic regression models, we estimated effects of gender on our study outcomes, overall and by household poverty. FINDINGS Women reported significantly more need for care for three of six chronic conditions surveyed, and they were more likely to have at least one of the conditions (OR 1.41 [95% CI 1.38, 1.44]). Among those with reported need for care, there were no consistent differences in access to care between women and men overall (e.g., treatment for all reported chronic conditions, OR 1.00 [0.96, 1.04]) or by household poverty. Of concern, access to care for chronic conditions was distressingly low among both men and women in many countries, as was access to preventive services among boys and girls less than 5 years old. CONCLUSIONS These cross-country results do not suggest a systematic disadvantage of women in access to curative care and medicines for treating selected chronic conditions or acute symptoms, or to preventive services among boys and girls.
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Stephens P, Ross-Degnan D, Wagner AK. Does access to medicines differ by gender? Evidence from 15 low and middle income countries. Health Policy 2013; 110:60-6. [PMID: 23422029 DOI: 10.1016/j.healthpol.2013.01.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 01/21/2013] [Accepted: 01/26/2013] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To examine gender differences in access to prescribed medicines in 15 lower and middle income countries. METHODS The proportion of consultations with at least one prescription for women in three age groups (<15, 15-59, 60+ years) with acute respiratory infections (ARI), depression and diabetes in routine audits was compared to the expected proportion calculated from WHO Global Burden of Disease estimates. Newer oral hypoglycaemic medication prescribing was also analysed. Differences reported by country, age group, and condition. FINDINGS 487,841 consultations examined between January 2007 and September 2010 in low (n = 1), lower middle (6), and upper middle income (8) countries. No country favoured one gender exclusively, but gender differences were common. Taking the 15 countries together, only diabetes treatment revealed a significant difference, with women being treated less often than expected (p = 0.02). No consistent differences found across countries grouped by World Bank income category, WHO region or Global Gender Gap Index. Overall, women had equal access to newer oral hypoglycaemics. CONCLUSION Gender differences in access to prescribed medicines for three common conditions are common, but favour neither gender consistently. This challenges prevailing hypotheses of systematic disparities in access to care for women. Evidence about gender disparities should influence policy design.
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Lu CY, Ross-Degnan D, Stephens P, Liu B, Wagner AK. Changes in use of antidiabetic medications following price regulations in China (1999–2009). JOURNAL OF PHARMACEUTICAL HEALTH SERVICES RESEARCH 2013. [DOI: 10.1111/jphs.12007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Abstract
Background and Objectives
Pharmaceutical expenditures are a major burden in China, partly because of pharmaceutical sales covering hospital operating costs, so a series of reductions in maximum retail prices of specific products, including antidiabetic medications, have been implemented. This is the first large-scale, longitudinal study evaluating effects of two rounds of price regulations on use of antidiabetic medications.
Methods
We used quarterly purchasing data collected by IMS Health from more than 1000 hospitals in China (1999–2009). We used interrupted time-series analysis to assess changes in the population-adjusted market volume of insulin and oral hypoglycaemic products and in the percentage market share of price-regulated products following price regulations implemented in December 2001 and December 2006.
Results
After the 2001 price regulation, there was a significant increase in market volume trend of insulin products (0.06 standard units/1000 population/quarter; 95% confidence interval: 0.04–0.08); utilisation of oral hypoglycaemic products remained stable. After the 2006 price regulation, there were significant increases in the market volume trend of both insulin products (0.18 standard units/1000 population/quarter; 0.12–0.23) and oral hypoglycaemic products (10.31 standard units/1000 population/quarter; 5.65–14.98). Market share of price-regulated insulin and oral hypoglycaemic products did not change significantly after either price regulation.
Conclusion
Our results indicate that lowering the retail prices of specific products was associated with increases in total per capita utilisation of antidiabetic medications without shifts in use between non- and price-regulated products. Broad volume increases suggest access to antidiabetic medications by additional people, increased use by those with prior access, or both.
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Pérez-Cuevas R, Doubova SV, Suarez-Ortega M, Law M, Pande AH, Escobedo J, Espinosa-Larrañaga F, Ross-Degnan D, Wagner AK. Evaluating quality of care for patients with type 2 diabetes using electronic health record information in Mexico. BMC Med Inform Decis Mak 2012; 12:50. [PMID: 22672471 PMCID: PMC3437217 DOI: 10.1186/1472-6947-12-50] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 06/06/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Several low and middle-income countries are implementing electronic health records (EHR). In the near future, EHRs could become an efficient tool to evaluate healthcare performance if appropriate indicators are developed. The aims of this study are: a) to develop quality of care indicators (QCIs) for type 2 diabetes (T2DM) in the Mexican Institute of Social Security (IMSS) health system; b) to determine the feasibility of constructing QCIs using the IMSS EHR data; and c) to evaluate the quality of care (QC) provided to IMSS patients with T2DM. METHODS We used a three-stage mixed methods approach: a) development of QCIs following the RAND-UCLA method; b) EHR data extraction and construction of indicators; c) QC evaluation using EHR data from 25,130 T2DM patients who received care in 2009. RESULTS We developed 18 QCIs, of which 14 were possible to construct using available EHR data. QCIs comprised both process of care and health outcomes. Several flaws in the EHR design and quality of data were identified. The indicators of process and outcomes of care suggested areas for improvement. For example, only 13.0% of patients were referred to an ophthalmologist; 3.9% received nutritional counseling; 63.2% of overweight/obese patients were prescribed metformin, and only 23% had HbA1c <7% (or plasma glucose≤130 mg/dl). CONCLUSIONS EHR data can be used to evaluate QC. The results identified both strengths and weaknesses in the electronic information system as well as in the process and outcomes of T2DM care at IMSS. This information can be used to guide targeted interventions to improve QC.
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Carapinha JL, Ross-Degnan D, Desta AT, Wagner AK. Health insurance systems in five Sub-Saharan African countries: medicine benefits and data for decision making. Health Policy 2010; 99:193-202. [PMID: 21167619 DOI: 10.1016/j.healthpol.2010.11.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Revised: 10/28/2010] [Accepted: 11/11/2010] [Indexed: 10/18/2022]
Abstract
Medicine benefits through health insurance programs have the potential to improve access to and promote more effective use of affordable, high quality medicines. Information is lacking about medicine benefits provided by health insurance programs in Sub-Saharan Africa. We describe the structure of medicine benefits and data routinely available for decision-making in 33 health insurance programs in Ghana, Kenya, Nigeria, Tanzania and Uganda. Most programs surveyed were private, for profit schemes covering voluntary enrollees, mostly in urban areas. Almost all provide both inpatient and outpatient medicine benefits, with members sharing the cost of medicines in all programs. Some programs use strategies that are common in high-income countries to manage the medicine benefits, such as formularies, generics policies, reimbursement limits, or price negotiation. Basic data to monitor performance in delivering medicine benefits are available in most programs, but key data elements and the resources needed to generate useful management information from the available data are typically missing. Many questions remain unanswered about the design, implementation, and effects of specific medicines policies in the emerging and expanding health insurance programs in Sub-Saharan Africa. These include questions about the most effective medicines policy choices, given different corporate and organizational structures and resources; impacts of specific benefit designs on quality and affordability of care and health outcomes; and ways to facilitate use of routine data for monitoring. Technical capacity building, strong government commitment, and international donor support will be needed to realize the benefits of medicines coverage in emerging and expanding health insurance programs in Sub-Saharan Africa.
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Wagner AK. TBI translational rehabilitation research in the 21st Century: exploring a Rehabilomics research model. Eur J Phys Rehabil Med 2010; 46:549-556. [PMID: 21224787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Globally, traumatic brain injury (TBI) is a leading cause of death and persistent disability. Although improvements in standard of care have reduced the overall mortality rates associated with this disease, there is a paucity of effective neuroprotective therapies. However, some rehabilitation focused strategies have shown promise with enhancing neurorecovery. One major challenge in identifying effective therapies is that TBI is an inherently heterogeneous disease. Despite many patients having similar injury factors and clinical care after their TBI, recovery and outcomes can be very different. This commentary discusses the value of treatment effectiveness research that also incorporates theranostic principles of individualized care. Key to this concept is the utilization of state-of-the-art biomarker platforms and technologies that can identify relevant molecular or physiological fingerprints that can assist rehabilitation practitioners in delineating long term outcome that can be linked to plasticity, treatment response, and natural recovery. This commentary proposes a unique concept of "Rehabilomics" as a field of study involving the systematic collection and study of rehabilitation relevant phenotypes, in conjunction with a transdisciplinary evaluation of biomarkers, in order to better understand the biology, function, prognosis, complications, treatments, adaptation, and recovery for persons with disabilities. Specific Rehabilomics applications to TBI research, as well as relevance to the National Institutes of Health Roadmap, are discussed.
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Chen W, Tang S, Sun J, Ross-Degnan D, Wagner AK. Availability and use of essential medicines in China: manufacturing, supply, and prescribing in Shandong and Gansu provinces. BMC Health Serv Res 2010; 10:211. [PMID: 20637116 PMCID: PMC2915989 DOI: 10.1186/1472-6963-10-211] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2010] [Accepted: 07/17/2010] [Indexed: 11/10/2022] Open
Abstract
Background The current health care reform in China launched in 2009 tackles the problem of access to appropriate medicines for its 1.3 billion people by focusing on providing essential medicines to all. To provide evidence for the reform process, we investigated the manufacturing, purchasing, and prescribing of essential medicines in two provinces. Methods We conducted surveys in 2007 of all manufacturers (n = 253) and of 59 purposively selected retail and 63 hospital pharmacies in Shandong and Gansu provinces to assess production and supply of products on the 2004 National Essential Medicines List (NEML), as well as factors underlying decision making about production and supply. We also reviewed prescriptions (n = 5456) in health facilities to calculate standard indicators of appropriate medicines use. Results Overall, manufacturers in Shandong and Gansu produced only 62% and 50%, respectively, of the essential medicines they were licensed to produce. Of a randomly selected 10% of NEML products, retail pharmacies stocked up to 60% of Western products. Median availability in hospital pharmacies ranged from 19% to 69%. Manufacturer and retail pharmacy managers based decisions on medicines production and stocking on economic considerations, while hospital pharmacy managers cited clinical need. Between 64% and 86% of prescriptions contained an essential medicine. However, overprescribing of antibiotics (34%-77% of prescriptions) and injectables (22%-61%) for adult non-infectious outpatient consultations was common. Conclusions We found that manufacturers, retail pharmacies, and hospital pharmacies paid limited attention to China's 2004 NEML in their decisions to manufacture, purchase, and stock essential medicines. We also found that prescribing of essential medicines was frequently inappropriate. These results should inform strategies to improve affordable access to essential medicines under the current health care reform.
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Briesacher BA, Ross-Degnan D, Wagner AK, Fouayzi H, Zhang F, Gurwitz JH, Soumerai SB. Out-of-pocket burden of health care spending and the adequacy of the Medicare Part D low-income subsidy. Med Care 2010; 48:503-9. [PMID: 20473197 PMCID: PMC3084515 DOI: 10.1097/mlr.0b013e3181dbd8d3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Evaluating the adequacy of Medicare prescription drug program (Part D) and its low-income subsidy (LIS) requires a comprehensive understanding of drug spending in relation to household resources. OBJECTIVE : To estimate out-of-pocket health care costs in the year before Part D, in context of total household spending, health status, and LIS eligibility. RESEARCH DESIGN Nationally representative cross-sectional study. SUBJECTS Two thousand two hundred thirty-one Medicare families in the 2005/2006 Health and Retirement Study. METHODS We assessed health care costs as a share of household resources remaining after spending on essential housing, food, personal care, and transportation. Burdensome health care costs were defined as exceeding 40% of nonessential resources. We used logistic regressions to assess the probability of incurring burdensome health expenditures, controlling for LIS eligibility. RESULTS In the year before Part D, more than half of Medicare families [56.0%; 95% confidence interval (CI): 55.3-59.9] experienced burdensome health care costs. Families in poor health allocated a median of 68.1% [interquartile range (IQR): 35.1-82.9] of nonessential resources to health care (compared with 34.0% median; IQR 11.9-52.2 among families in excellent health, P < 0.011). Most (64%) out-of-pocket health care spending was allocated to health insurance premiums and medications. As many as 26% of Medicare families had burdensome health care costs but were not eligible for LIS assistance. CONCLUSIONS Before Part D, burdensome health care expenditures were common in Medicare families. Our estimates of Part D and LIS benefits indicate a limited scope of relief.
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Ross-Degnan D, Pierre-Jacques M, Zhang F, Tadeg H, Gitau L, Ntaganira J, Balikuddembe R, Chalker J, Wagner AK. Measuring adherence to antiretroviral treatment in resource-poor settings: the clinical validity of key indicators. BMC Health Serv Res 2010; 10:42. [PMID: 20170478 PMCID: PMC2834585 DOI: 10.1186/1472-6963-10-42] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Accepted: 02/19/2010] [Indexed: 11/12/2022] Open
Abstract
Background Access to antiretroviral therapy has dramatically expanded in Africa in recent years, but there are no validated approaches to measure treatment adherence in these settings. Methods In 16 health facilities, we observed a retrospective cohort of patients initiating antiretroviral therapy. We constructed eight indicators of adherence and visit attendance during the first 18 months of treatment from data in clinic and pharmacy records and attendance logs. We measured the correlation among these measures and assessed how well each predicted changes in weight and CD4 count. Results We followed 488 patients; 63.5% had 100% coverage of medicines during follow-up; 2.7% experienced a 30-day gap in treatment; 72.6% self-reported perfect adherence in all clinic visits; and 19.9% missed multiple clinic visits. After six months of treatment, mean weight gain was 3.9 kg and mean increase in CD4 count was 138.1 cells/mm3. Dispensing-based adherence, self-reported adherence, and consistent visit attendance were highly correlated. The first two types of adherence measure predicted gains in weight and CD4 count; consistent visit attendance was associated only with weight gain. Conclusions This study demonstrates that routine data in African health facilities can be used to monitor antiretroviral adherence at the patient and system level.
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Zhang F, Wagner AK, Soumerai SB, Ross-Degnan D. Methods for estimating confidence intervals in interrupted time series analyses of health interventions. J Clin Epidemiol 2008; 62:143-8. [PMID: 19010644 DOI: 10.1016/j.jclinepi.2008.08.007] [Citation(s) in RCA: 174] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Revised: 07/31/2008] [Accepted: 08/09/2008] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Interrupted time series (ITS) is a strong quasi-experimental research design, which is increasingly applied to estimate the effects of health services and policy interventions. We describe and illustrate two methods for estimating confidence intervals (CIs) around absolute and relative changes in outcomes calculated from segmented regression parameter estimates. STUDY DESIGN AND SETTING We used multivariate delta and bootstrapping methods (BMs) to construct CIs around relative changes in level and trend, and around absolute changes in outcome based on segmented linear regression analyses of time series data corrected for autocorrelated errors. RESULTS Using previously published time series data, we estimated CIs around the effect of prescription alerts for interacting medications with warfarin on the rate of prescriptions per 10,000 warfarin users per month. Both the multivariate delta method (MDM) and the BM produced similar results. CONCLUSION BM is preferred for calculating CIs of relative changes in outcomes of time series studies, because it does not require large sample sizes when parameter estimates are obtained correctly from the model. Caution is needed when sample size is small.
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