Potential Bias in Medication Adherence Studies of Prevalent Users

Purpose

We examined how the choice of historic medication use criteria for identifying prevalent users may bias estimated adherence changes associated with a medication copayment increase.

Methods

From pharmacy claims data in a retrospective cohort study, we identified 6,383 prevalent users of oral diabetes medications from four VA Medical Centers. Patients were included in this prevalent cohort if they had one fill both 3 months prior and 4–12 months prior to the index date, defined as the month in which medication copayments increased. To determine whether these historic medication use criteria introduced bias in the estimated response to a $5 medication copayment increase, we compared adherence trends from cohorts defined from different medication use criteria and from different index dates of copayment change. In an attempt to validate the prior observation of an upward trend in adherence prior to the date of the policy change, we replicated time series analyses varying the index dates prior to and following the date of the policy change, hypothesizing that the trend line associated with the policy change would differ from the trend lines that were not.

Results

Medication adherence trends differed when different medication use criteria were applied. Contrary to our expectations, similar adherence trends were observed when the same medication use criteria were applied at index dates when no copayment changes occurred.

Conclusion

To avoid introducing bias due to study design in outcomes assessments of medication policy changes, historic medication use inclusion criteria must be chosen carefully when constructing cohorts of prevalent users. Furthermore, while pharmacy data have enormous potential for population research and monitoring, there may be inherent logical flaws that limit cohort identification solely through administrative pharmacy records.     

Effects of Copayment in Long-Term Care Insurance on Long-Term Care and Medical Care Expenditure

ObjectiveThis study aimed to clarify the difference in (1) long-term care (LTC) usage and expenditure and (2) medical care service usage and expenditure before and after the change in the copayment limit for qualifying individuals from 10% to 20%.Setting and ParticipantsThis quasi-experimental longitudinal design used the database from 1 prefecture of Japan that included 570,434 person-month records of 23,879 insured individuals (in August 2014) who used LTC services between August 2014 and July 2015 and were aged 65 years and older on August 1, 2014.MethodsWe conducted difference-in-difference estimations to compare “before” and “after” outcome differences between insured individuals whose LTC copayment increased to 20% and those whose copayment remained at 10%. Sex, age, Care Needs Level, subsidy, and public assistance were adjusted in the models, along with robustness checks.ResultsDifferences in both insurer's payment and insured's copayment indicated statistical significance between those whose copayment increased and those whose copayment did not increase. We found no significant difference in the number of minutes of home care service use, days of facility care service use, and LTC expenditures among those with copayment increases as well as those with no increase in copayment following the insured's copayment increase policy implementation. In contrast, the policy implementation caused significant differences in the number of days of hospitalization, medical care expenditures, and total expenditures.Conclusions and ImplicationsThe increase in insured individuals' copayment decreased LTC insurer's payment. However, total LTC expenditure increased over time although the increase trend slowed down in the treatment group after the copayment increase policy implemented. Besides, medical care expenditure increased consistently among insured individuals whose copayment increased. As there appears to be a “balloon effect” between LTC and medical care services, it is important to discuss the medical care system while considering the LTC insurance system comprehensively.     

Association between non-profit hospital community benefit spending and health outcomes

Objective

To determine if greater non-profit hospital spending for community benefits is associated with better health outcomes in the county where they are located.

Data Sources and Study Setting

Community benefit data from IRS Form 990/Schedule H was linked to health outcome data from Area Health Resource Files, Map the Meal Gap, and Medicare claims from the Center for Medicare and Medicaid Services at the county level. Counties with at least one non-profit hospital in the United States from 2015 to 2019 (N = 5469 across the 5 years) were included.

Study Design

We ran multiple regressions on community benefit expenditures linked with the number of health professionals, food insecurity, and adherence to diabetes and hypertension medication for each county.

Data Collection

The three outcomes were chosen based on prior studies of community benefit and a recent survey sent to 12 health care executives across four regions of the U.S. Data on community benefit expenditures and health outcomes were aggregated at the county level.

Principal Findings

Average hospital community benefit spending in 2019 was $63.6 million per county ($255 per capita). Multivariable regression results did not demonstrate significant associations of total community benefit spending with food insecurity or medication adherence for diabetes. Statistically significant associations with the number of health professionals per 1000 (coefficient, 12.10; SE, 0.32; p < 0.001) and medication adherence for hypertension (marginal effect, 0.27; SE, 0.09; p = 0.003) were identified, but both would require very large increases in community benefit spending to meaningfully improve outcomes.

Conclusions

Despite varying levels of non-profit hospital community benefit investment across counties, higher community benefit expenditures are not associated with an improvement in the selected health outcomes at the county level. Hospitals can use this information to reassess community benefit strategies, while federal, state, and local governments can use these findings to redefine the measures of community benefit they use to monitor and grant tax exemption.     

Changes in per member per month expenditures after implementation of Florida's Medicaid reform demonstration

Objective. To determine the impact of Florida's Medicaid Reform Demonstration on per member per month (PMPM) Medicaid expenditures. Data. Florida Medicaid claims data from the two fiscal years before implementation of the Demonstration (FY0405, FY0506) and the first two fiscal years after implementation (FY0607, FY0708) from two reform counties and two nonreform counties. Study Design. A difference‐in‐difference approach was used to compare changes in expenditures before and after implementation of reforms between the reform counties and the nonreform counties. Data Extraction. Medicaid claims and eligibility files were extracted for enrollees in the reform and nonreform counties and collapsed into monthly amounts (N=16,875,467). Principal Findings. When examining the entire population, the reforms had little impact on PMPM expenditures, particularly among SSI enrollees. PMPM expenditures for SSI enrollees increased by an additional U.S.$0.35 in the reform counties compared with the nonreform counties and increased by an additional U.S.$2.38 for Temporary Assistance for Needy Families (TANF) enrollees. An analysis that limited the sample to individuals with at least 3 or 6 months of observations pre‐ and postimplementation, however, showed reduced PMPM expenditures of U.S.$11.15–U.S.$19.44 PMPM for both the SSI and TANF populations. Conclusions. Although Medicaid reforms in Florida did not result in significant reductions in PMPM expenditures when examining the full population, it does appear that expenditure reductions may be achieved among Medicaid enrollees with more stable enrollment, who have more exposure to managed care activities and may have more health care needs than the overall Medicaid population.     

Effect of eliminating behavioral health benefits for selected medicaid enrollees

Objective. To determine the extent to which the elimination of behavioral health benefits for selected beneficiaries of Oregon's Medicaid program affected general medical expenditures among enrollees using outpatient mental health and substance abuse treatment services.
Data Source/Study Setting. Twelve months of claims before and 12 months following a 2003 policy change, which included the elimination of the behavioral health benefit for selected Oregon Medicaid enrollees.
Study Design. We use a difference-in-differences approach to estimate the change in general medical expenditures following the 2003 policy change. We compare two methodological approaches: regression with propensity score weighting; and one-to-one covariate matching.
Principal Findings. Enrollees who had accessed the substance abuse treatment benefit demonstrated substantial and statistically significant increases in expenditures. Individuals who accessed the outpatient mental health benefit demonstrated a decrease or no change in expenditures, depending on model specification.
Conclusions. Elimination of the substance abuse benefit led to increased medical expenditures, although this offset was still smaller than the total cost of the benefit. In contrast, individuals who accessed the outpatient mental health benefit did not exhibit a similar increase, although these individuals did not include a portion of the Medicaid population with severe mental illnesses.     

Transportation brokerage services and Medicaid beneficiaries' access to care

Objective. To examine the effect of capitated transportation brokerage services on Medicaid beneficiaries' access to care and expenditures.
Data Sources/Study Setting. The study period from 1996 to 1999 corresponds to the period of a natural experiment during which Georgia and Kentucky implemented transportation brokerage services. Effects were estimated for asthmatic children and diabetic adults.
Study Design. We used difference-in-differences models to assess the effects of transportation brokerage services on access to care, measured by Medicaid expenditures and health services use. The study design is strengthened by the staggered implementation dates between states and within each state.
Principal Findings. For asthmatic children, transportation brokerage services increased nonemergency transportation expenditures and the likelihood of using any services; reductions in monthly expenditures more than offsetting the increased transportation costs. For diabetic adults, nonemergency transportation costs decreased despite increased monthly use of health services; average monthly medical expenditures and the likelihood of hospital admission for an ambulatory care-sensitive condition (ACSC) also decreased.
Conclusions. The shift to transportation brokerage services improved access to care among Medicaid beneficiaries and decreased the expenditures. The increase in access combined with reduced hospitalizations for asthmatic children and ACSC admissions for diabetic adults are suggestive of improvements in health outcomes.     

Factors related to Medicaid payment acceptance at outpatient substance abuse treatment programs

Objective. To examine factors associated with Medicaid acceptance for substance abuse (SA) services by outpatient SA treatment programs. Data Sources. Secondary analysis of 2003–2006 National Survey of Substance Abuse Treatment Services data combined with state Medicaid policy and usage measures and other publicly available data. Study Design. We used cross‐sectional analyses, including state fixed effects, to assess relationships between SA treatment program Medicaid acceptance and (1) program‐level factors, (2) county‐level sociodemographics and treatment program density, and (3) state‐level population characteristics, SA treatment‐related factors, and Medicaid policy and usage. Data Extraction Methods. State Medicaid policy data were compiled based on reviews of state Medicaid‐related statutes/regulations and Medicaid plans. Other data were publicly available. Principal Findings. Medicaid acceptance was significantly higher for programs: (a) that were publicly funded and in states with Medicaid policy allowing SA treatment coverage; (b) with accreditation/licensure and nonprofit/government ownership, as well as mental‐ and general‐health focused programs; and (c) in counties with lower household income. Conclusions. SA treatment program Medicaid acceptance related to program‐, county, and state‐level factors. The data suggest the importance of state policy and licensure/accreditation requirements in increasing SA program Medicaid access.     

Copayment reductions generate greater medication adherence in targeted patients

A large value-based insurance design program offered by Blue Cross Blue Shield of North Carolina eliminated generic medication copayments and reduced copayments for brand-name medications. Our study showed that the program improved adherence to medications for diabetes, hypertension, hyperlipidemia, and congestive heart failure. We found that adherence improved for enrollees, ranging from a gain of 3.8?percentage points for patients with diabetes to 1.5?percentage points for those taking calcium-channel blockers, when compared to others whose employers did not offer a similar program. An examination of longer-term adherence and trends in health care spending is still needed to provide a compelling evidence base for value-based insurance design.     

Incentives in a Medicaid carve-out: impact on children with special health care needs

Objective. To evaluate whether a specialty care payment "carve-out" from Medicaid managed care affects caseloads and expenditures for children with chronic conditions.
Data Source. Paid Medicaid claims in California with service dates between 1994 and 1997 that were authorized by the Title V Children with Special Health Needs program for children under age 21.
Study Design. A natural experiment design evaluated the impact of California's Medicaid managed care expansion during the 1990s, which preserved fee-for-service payment for certain complex medical diagnoses. Outcomes in time series regression include Title V program participation and expenditures. Multiple comparison groups include children in managed care counties who were not mandated to enroll, and children in nonmanaged care counties.
Data Collection/Extraction Methods. Data on the study population were obtained from the state health department claims files and from administrative files on enrollment and managed care participation.
Principal Findings. The carve-out policy increased the number of children receiving Title V-authorized services. Recipients and expenditures for some ambulatory services increased, although overall expenditures (driven by inpatient services) did not increase significantly. Cost intensity per Title V recipient generally declined.
Conclusions. The carve-out policy increased identification of children with special health care needs. The policy may have improved children's access to prevailing standards of care by motivating health plans and providers to identify and refer children to an important national program.     

Cost-effectiveness of antidepressant medications

BACKGROUND: Antidepressant medications have been shown to effectively relieve symptoms, improve interpersonal and occupational functioning and reduce disability from coexisting medical conditions. Although the newer selective serotonin reuptake inhibitors (SSRIs) have improved tolerability, are easier to take and are associated with longer lengths of therapy when compared with the tricyclic antidepressants (TCAs), the relative cost-effectiveness of alternative antidepressants remains unclear. AIMS OF THE STUDY: This study seeks to determine (i) the probability that relapse or recurrence of depression can be prevented by appropriate antidepressant choice, (ii) the cost associated with relapse or recurrence of depression and (iii) the relative cost-effectiveness of alternative antidepressants. METHODS: We use a quasi-experimental design to compare claims from a state Medicaid plan for TCA and SSRIs users. RESULTS: Premature discontinuation of antidepressant medication is the strongest predictor of relapse and recurrence. Antidepressant choice was not an independent predictor of relapse or recurrence. The effect of relapse and recurrence on expenditures is complex, with a non-significant trend toward lower expenditures for those who had longer periods between episodes of depression two years after initiation of treatment for the first episode. We were unable to replicate prior research results regarding the impact of SSRIs on duration of therapy in this Medicaid plan. CONCLUSIONS: Premature discontinuation of antidepressant treatment is associated with a high probability of relapse and recurrence. Health care expenditures are not altered by preventing relapse and recurrence. We suggest that antidepressant medications associated with reduced probability of premature discontinuation should be considered cost-effective. IMPLICATIONS FOR HEALTH CARE PROVISION AND USE: There are very few variables which health care providers can use to improve the outcomes and associated economic consequences of depression. Among these factors, treatment choice and adherence to the prescribed treatment are likely candidates. In this paper, we suggest that adherence to antidepressant medication results in substantial improvement in the time to relapse or recurrence of depression. Choice of an SSRI may thus improve treatment outcome by lengthening remission. In addition, this choice is not associated with higher costs. IMPLICATIONS FOR HEALTH POLICY FORMULATION: Depressive illnesses are associated with high rates of health service use and functional impairment. Thus, the societal burden is quite high. This paper furthers the debate regarding the relative cost-effectiveness of antidepressant medications, and our findings suggest several ways that policy makers can improve the care of depressed individuals at little additional cost. Specifically our findings highlight the importance of adherence to current recommendations regarding the length of antidepressant treatment and suggest several methods for improving this important outcome. IMPLICATIONS FOR FURTHER RESEARCH: The relative cost-effectiveness of alternative antidepressant medications continues to be an important and unsolved issue. We suggest the need for future research in this area using a variety of research designs appropriate to the question. The quasi-experimental approach outlined here seems promising in this regard.     

Where You Live Matters: Quality and Racial/Ethnic Disparities in Schizophrenia Care in Four State Medicaid Programs

Objective

To determine whether (a) quality in schizophrenia care varies by race/ethnicity and over time and (b) these patterns differ across counties within states.

Data Sources

Medicaid claims data from California, Florida, New York, and North Carolina during 2002–2008.

Study Design

We studied black, Latino, and white Medicaid beneficiaries with schizophrenia. Hierarchical regression models, by state, quantified person and county effects of race/ethnicity and year on a composite quality measure, adjusting for person-level characteristics.

Principal Findings

Overall, our cohort included 164,014 person-years (41–61 percent non-whites), corresponding to 98,400 beneficiaries. Relative to whites, quality was lower for blacks in every state and also lower for Latinos except in North Carolina. Temporal improvements were observed in California and North Carolina only. Within each state, counties differed in quality and disparities. Between-county variation in the black disparity was larger than between-county variation in the Latino disparity in California, and smaller in North Carolina; Latino disparities did not vary by county in Florida. In every state, counties differed in annual changes in quality; by 2008, no county had narrowed the initial disparities.

Conclusions

For Medicaid beneficiaries living in the same state, quality and disparities in schizophrenia care are influenced by county of residence for reasons beyond patients’ characteristics.     

Medication use and knowledge in a sample of Indigenous and non‐Indigenous prisoners

Objective : To (a) characterise medication use and knowledge, according to Indigenous status, and (b) identify independent correlates of medication knowledge in a sample of adult prisoners. Methods : Cross‐sectional survey of 1,231 adult prisoners in Queensland, interviewed within six weeks of release. Measures included self‐reported demographic and health‐related characteristics, self‐reported use of medications, the Hayes Ability Screening Index (HASI) and the Short‐Form Health Survey (SF‐36). Objective medication data were abstracted from prison medical records. A medication knowledge score was calculated to reflect the agreement between self‐reported and objective medication use. Results : 46% of participants were taking at least one medication. The most common class of medication was Central Nervous System (30% of participants). Medication knowledge was generally poor, with one quarter of prisoners unable to accurately identify any of their medications. Independent correlates of poor medication knowledge included not taking Central Nervous System medications, identifying as Indigenous and age >54. Conclusions and Implications : Around half prisoners are taking medications in prison, but most have poor knowledge of what these medications are. Medication knowledge is associated with better adherence and may contribute to improved health outcomes post‐release. Changes to prescribing and dispensing practices in prison may improve medication knowledge and health outcomes in this profoundly marginalised group.