Person: Zhang, Fang
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Publication Impact of Emerging Health Insurance Arrangements on Diabetes Outcomes and Disparities: Rationale and Study Design
(Centers for Disease Control and Prevention, 2013) Wharam, James; Soumerai, Steve; Trinacty, Connie; Eggleston, Emma; Zhang, Fang; LeCates, Robert; Canning, Claire; Ross-Degnan, DennisConsumer-directed health plans combine lower premiums with high annual deductibles, Internet-based quality-of-care information, and health savings mechanisms. These plans may encourage members to seek better value for health expenditures but may also decrease essential care. The expansion of high-deductible health plans (HDHPs) represents a natural experiment of tremendous proportion. We designed a pre–post, longitudinal, quasi-experimental study to determine the effect of HDHPs on diabetes quality of care, outcomes, and disparities. We will use a 13-year rolling sample (2001–2013) of members of an HDHP and members of a control group. To reduce selection bias, we will limit participants to those whose employers mandate a single health insurance type. The study will measure rates of monthly hemoglobin A1c, lipid, and albuminuria testing; availability of blood glucose test strips; and rates of retinal examinations, high-severity emergency department visits, and preventable hospitalizations. Results could be used to design health plan features that promote high-quality care and better outcomes among people who have diabetes.
Publication Need for and Access to Health Care and Medicines: Are There Gender Inequities?
(Public Library of Science, 2013) Wagner, Anita; Graves, Amy J.; Fan, Zhengyu; Walker, Saul; Zhang, Fang; Ross-Degnan, DennisObjective: 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.
Publication Measuring Adherence to Antiretroviral Treatment in Resource-poor Settings: The Clinical Validity of Key Indicators
(BioMed Central, 2010) Ross-Degnan, Dennis; Pierre-Jacques, Marsha; Zhang, Fang; Tadeg, Hailu; Gitau, Lillian; Ntaganira, Joseph; Balikuddembe, Robert; Chalker, John C.; Wagner, Anita; INRUD IAABackground: 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.
Publication Racial differences in long-term adherence to oral antidiabetic drug therapy: a longitudinal cohort study
(BioMed Central, 2009) Trinacty, Connie; Adams, Alyce S; Soumerai, Stephen; Zhang, Fang; Meigs, James; Piette, John D; Ross-Degnan, DennisBackground: Adherence to oral antidiabetic medications is often suboptimal. Adherence differences may contribute to health disparities for black diabetes patients, including higher microvascular event rates, greater complication-related disability, and earlier mortality. Methods: In this longitudinal retrospective cohort study, we used 10 years of patient-level claims and electronic medical record data (1/1/1992–12/31/2001) to assess differences in short- and long-term adherence to oral antidiabetic medication among 1906 newly diagnosed adults with diabetes (26% black, 74% white) in a managed care setting in which all members have prescription drug coverage. Four main outcome measures included: (1) time from diabetes diagnosis until first prescription of oral antidiabetic medication; (2) primary adherence (time from first prescription to prescription fill); (3) time until discontinuation of oral antidiabetic medication from first prescription; and (4) long-term adherence (amount dispensed versus amount prescribed) over a 24-month follow-up from first oral antidiabetic medication prescription. Results: Black patients were as likely as whites to initiate oral therapy and fill their first prescription, but experienced higher rates of medication discontinuation (HR: 1.8, 95% CI: 1.2, 2.7) and were less adherent over time. These black-white differences increased over the first six months of therapy but stabilized thereafter for patients who initiated on sulfonylureas. Significant black-white differences in adherence levels were constant throughout follow-up for patients initiated on metformin therapy. Conclusion: Racial differences in adherence to oral antidiabetic drug therapy persist even with equal access to medication. Early and continued emphasis on adherence from initiation of therapy may reduce persistent racial differences in medication use and clinical outcomes.
Publication Impact of pharmaceutical policy interventions on utilization of antipsychotic medicines in Finland and Portugal in times of economic recession: interrupted time series analyses
(BioMed Central, 2014) Leopold, Christine; Zhang, Fang; Mantel-Teeuwisse, Aukje K; Vogler, Sabine; Valkova, Silvia; Ross-Degnan, Dennis; Wagner, AnitaObjectives: To analyze the impacts of pharmaceutical sector policies implemented to contain country spending during the economic recession – a reference price system in Finland and a mix of policies including changes in reimbursement rates, a generic promotion campaign and discounts granted to the public payer in Portugal – on utilization of, as a proxy for access to, antipsychotic medicines. Methodology We obtained monthly IMS Health sales data in standard units of antipsychotic medicines in Portugal and Finland for the period January 2007 to December 2011. We used an interrupted time series design to estimate changes in overall use and generic market shares by comparing pre-policy and post-policy levels and trends. Results: Both countries’ policy approaches were associated with slight, likely unintended, decreases in overall use of antipsychotic medicines and with increases in generic market shares of major antipsychotic products. In Finland, quetiapine and risperidone generic market shares increased substantially (estimates one year post-policy compared to before, quetiapine: 6.80% [3.92%, 9.68%]; risperidone: 11.13% [6.79%, 15.48%]. The policy interventions in Portugal resulted in a substantially increased generic market share for amisulpride (estimate one year post-policy compared to before: 22.95% [21.01%, 24.90%]; generic risperidone already dominated the market prior to the policy interventions. Conclusions: Different policy approaches to contain pharmaceutical expenditures in times of the economic recession in Finland and Portugal had intended – increased use of generics – and likely unintended – slightly decreased overall sales, possibly consistent with decreased access to needed medicines – impacts. These findings highlight the importance of monitoring and evaluating the effects of pharmaceutical policy interventions on use of medicines and health outcomes.
Publication Drug Adverse Event Detection in Health Plan Data Using the Gamma Poisson Shrinker and Comparison to the Tree-based Scan Statistic
(MDPI, 2013) Brown, Jeffrey; Petronis, Kenneth R.; Bate, Andrew; Zhang, Fang; Dashevsky, Inna; Kulldorff, Martin; Avery, Taliser; Davis, Robert L.; Chan, K. Arnold; Andrade, Susan E.; Boudreau, Denise; Gunter, Margaret J.; Herrinton, Lisa; Pawloski, Pamala A.; Raebel, Marsha A.; Roblin, Douglas; Smith, David; Reynolds, RobertBackground: Drug adverse event (AE) signal detection using the Gamma Poisson Shrinker (GPS) is commonly applied in spontaneous reporting. AE signal detection using large observational health plan databases can expand medication safety surveillance. Methods: Using data from nine health plans, we conducted a pilot study to evaluate the implementation and findings of the GPS approach for two antifungal drugs, terbinafine and itraconazole, and two diabetes drugs, pioglitazone and rosiglitazone. We evaluated 1676 diagnosis codes grouped into 183 different clinical concepts and four levels of granularity. Several signaling thresholds were assessed. GPS results were compared to findings from a companion study using the identical analytic dataset but an alternative statistical method—the tree-based scan statistic (TreeScan). Results: We identified 71 statistical signals across two signaling thresholds and two methods, including closely-related signals of overlapping diagnosis definitions. Initial review found that most signals represented known adverse drug reactions or confounding. About 31% of signals met the highest signaling threshold. Conclusions: The GPS method was successfully applied to observational health plan data in a distributed data environment as a drug safety data mining method. There was substantial concordance between the GPS and TreeScan approaches. Key method implementation decisions relate to defining exposures and outcomes and informed choice of signaling thresholds.
Publication Changes in antidepressant use by young people and suicidal behavior after FDA warnings and media coverage: quasi-experimental study
(BMJ Publishing Group Ltd., 2014) Lu, Christine; Zhang, Fang; Lakoma, Matthew D; Madden, Jeanne; Rusinak, Donna; Penfold, Robert B; Simon, Gregory; Ahmedani, Brian K; Clarke, Gregory; Hunkeler, Enid M; Waitzfelder, Beth; Owen-Smith, Ashli; Raebel, Marsha A; Rossom, Rebecca; Coleman, Karen J; Copeland, Laurel A; Soumerai, StephenObjective: To investigate if the widely publicized warnings in 2003 from the US Food and Drug Administration about a possible increased risk of suicidality with antidepressant use in young people were associated with changes in antidepressant use, suicide attempts, and completed suicides among young people. Design: Quasi-experimental study assessing changes in outcomes after the warnings, controlling for pre-existing trends. Setting: Automated healthcare claims data (2000-10) derived from the virtual data warehouse of 11 health plans in the US Mental Health Research Network. Participants: Study cohorts included adolescents (around 1.1 million), young adults (around 1.4 million), and adults (around 5 million). Main outcome measures Rates of antidepressant dispensings, psychotropic drug poisonings (a validated proxy for suicide attempts), and completed suicides. Results: Trends in antidepressant use and poisonings changed abruptly after the warnings. In the second year after the warnings, relative changes in antidepressant use were −31.0% (95% confidence interval −33.0% to −29.0%) among adolescents, −24.3% (−25.4% to −23.2%) among young adults, and −14.5% (−16.0% to −12.9%) among adults. These reflected absolute reductions of 696, 1216, and 1621 dispensings per 100 000 people among adolescents, young adults, and adults, respectively. Simultaneously, there were significant, relative increases in psychotropic drug poisonings in adolescents (21.7%, 95% confidence interval 4.9% to 38.5%) and young adults (33.7%, 26.9% to 40.4%) but not among adults (5.2%, −6.5% to 16.9%). These reflected absolute increases of 2 and 4 poisonings per 100 000 people among adolescents and young adults, respectively (approximately 77 additional poisonings in our cohort of 2.5 million young people). Completed suicides did not change for any age group. Conclusions: Safety warnings about antidepressants and widespread media coverage decreased antidepressant use, and there were simultaneous increases in suicide attempts among young people. It is essential to monitor and reduce possible unintended consequences of FDA warnings and media reporting.
Publication Depression and Cost-Related Medication Nonadherence in Medicare Beneficiaries
(American Medical Association (AMA), 2007) Bambauer, Kara Zivin; Safran, Dana Gelb; Ross-Degnan, Dennis; Zhang, Fang; Adams, Alyce S.; Gurwitz, Jerry; Pierre-Jacques, Marsha; Soumerai, StephenContext Treatment for depression can be expensive and depression can affect the use of other medical services, yet there is little information on how depression affects the prevalence of cost-related medication nonadherence (CRN) in elderly patients and patients with disabilities.
Objective To quantify the presence of CRN in depressed and nondepressed elderly Medicare beneficiaries and nonelderly Medicare beneficiaries with disabilities prior to the implementation of the Medicare Drug Benefit.
Design and Setting 2004 Medicare Current Beneficiary Survey.
Participants Depressed and nondepressed elderly Medicare beneficiaries and beneficiaries with disabilities.
Main Outcome Measures Cost-related medication nonadherence included taking smaller doses or skipping doses of a prescription to make it last longer, or failing to fill a prescription because of cost, controlling for health insurance status, comorbid conditions, age, race, sex, and functional status.
Results In a nationally representative sample of 13 835 noninstitutionalized elderly Medicare enrollees and Medicare enrollees with disabilities, 44% of beneficiaries with disabilities and 13% of elderly beneficiaries reported being depressed during the previous year. Among enrollees with disabilities reporting depressive symptoms, 38% experienced CRN compared with 22% of enrollees with disabilities who did not report depressive symptoms. Among elderly enrollees who reported depressive symptoms, 19% experienced CRN, compared with 12% of elderly enrollees who did not report such symptoms. In adjusted analyses, depressive symptoms remained a significant predictor of CRN in both groups (persons with disabilities: odds ratio, 1.7; 95% confidence interval, 1.3-2.3; elderly persons: odds ratio, 1.4; 95% confidence interval, 1.1-1.7).
Conclusions Depressive symptoms were associated with CRN in elderly Medicare enrollees and Medicare enrollees with disabilities. Providers should elicit information on economic barriers that might interfere with treatment of Medicare beneficiaries with depression.
Publication Effect of pay for performance on the management and outcomes of hypertension in the United Kingdom: interrupted time series study
(BMJ, 2011) Serumaga, B.; Ross-Degnan, Dennis; Avery, A. J.; Elliott, R. A.; Majumdar, S. R.; Zhang, Fang; Soumerai, StephenObjective To assess the impact of a pay for performance incentive on quality of care and outcomes among UK patients with hypertension in primary care.
Design Interrupted time series.
Setting The Health Improvement Network (THIN) database, United Kingdom.
Participants 470 725 patients with hypertension diagnosed between January 2000 and August 2007.
Intervention The UK pay for performance incentive (the Quality and Outcomes Framework), which was implemented in April 2004 and included specific targets for general practitioners to show high quality care for patients with hypertension (and other diseases).
Main outcome measures Centiles of systolic and diastolic blood pressures over time, rates of blood pressure monitoring, blood pressure control, and treatment intensity at monthly intervals for baseline (48 months) and 36 months after the implementation of pay for performance. Cumulative incidence of major hypertension related outcomes and all cause mortality for subgroups of newly treated (treatment started six months before pay for performance) and treatment experienced (started treatment in year before January 2001) patients to examine different stages of illness.
Results After accounting for secular trends, no changes in blood pressure monitoring (level change 0.85, 95% confidence interval −3.04 to 4.74, P=0.669 and trend change −0.01, −0.24 to 0.21, P=0.615), control (−1.19, −2.06 to 1.09, P=0.109 and −0.01, −0.06 to 0.03, P=0.569), or treatment intensity (0.67, −1.27 to 2.81, P=0.412 and 0.02, −0.23 to 0.19, P=0.706) were attributable to pay for performance. Pay for performance had no effect on the cumulative incidence of stroke, myocardial infarction, renal failure, heart failure, or all cause mortality in both treatment experienced and newly treated subgroups.
Conclusions Good quality of care for hypertension was stable or improving before pay for performance was introduced. Pay for performance had no discernible effects on processes of care or on hypertension related clinical outcomes. Generous financial incentives, as designed in the UK pay for performance policy, may not be sufficient to improve quality of care and outcomes for hypertension and other common chronic conditions.
Publication Mammography Rates 3 Years After the 2009 US Preventive Services Task Force Guidelines Changes
(American Society of Clinical Oncology (ASCO), 2015) Wharam, James; Landon, Bruce; Zhang, Fang; Xu, Xin; Soumerai, Stephen; Ross-Degnan, DennisPurpose In November 2009, the US Preventive Services Task Force (USPSTF) changed its mammography recommendations from every 1 to 2 years among women age ≥ 40 years to personalized screening decisions for women age 40 to 49 years and screening every 2 years for women age 50 to 74 years.
Methods We studied mammography trends among 5.5 million women age 40 to 64 years enrolled in a large national health insurer. We used 2005 to 2009 mammography trends to predict 2012 rates. Our primary measure was the estimated difference between observed and predicted 2012 annual and biennial mammography rates. We stratified results by age group and race/ethnicity.
Results Among women age 40 to 49 years, 2012 mammography rates declined by 9.9% (95% CI, −10.4% to −9.3%) relative to the predicted 2012 rate. Decreases were lowest among black women (−2.3%; 95% CI, −6.3% to 1.8%) and highest among Asian women (−17.4; 95% CI, −20.0 to −14.8). Annual mammography rates among women age 50 to 64 years declined by 6.1% (95% CI, −6.5% to −5.7%) by 2012. Regarding biennial mammography rates, women age 40 to 49 years experienced a 9.0% relative reduction (95% CI, −9.6% to −8.4%). White, Hispanic, and Asian women age 40 to 49 years demonstrated similar relative reductions of approximately 9% to 11%, whereas black women had no detectable changes (0.1%; 95% CI, −4.0% to 4.3%). Women age 50 to 64 years had a 6.2% relative reduction (95% CI, −6.6% to −5.7%) in biennial mammography that was similar among white, Hispanic, and Asian women. Black women age 50 to 64 years did not have changes in biennial mammography (0.4%; 95% CI, −2.6% to 3.5%).
Conclusion Three years after publication of the 2009 USPSTF guidelines, mammography rates declined by 6% to 17% among white, Hispanic, and Asian women but not among black women. Small reductions in biennial mammography might be an unintended consequence of the updated guidelines.
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