Propensity Score Matching with Limited Overlap

In this article, we have demostrated the application of two newly proposed estimators which accounts for lack of overlap under propensity score matching on a case study involing the analysis of health expenditure data for the United States.

Publications over the Academic Life-cycle: Evidence for Academic Economists

It is widely assumed that the productivity of academic specialists declines with academic age. This paper provides empirical evidence of this phenomenon among economists using a panel data set from the departments of nine major midwestern universities.

The return of publications for economics faculty

This study uses comprehensive panel data to determine the effect of publications on the salaries of full-time economics faculty in nine midwestern universities. The data set allows us to control not only the volume but also the quality of publications. Recent developments in the ISI-Web of science enable us to divide total citations per faculty member into citations by others and self-citations. Since none of the traditional measures (citations, publication indexes, total article pages) when used individually fully accounts for all research output, all available measures should be used. Our findings indicate that average number of article-pages published in The American Economic Review (AER) are likely to increase salary by %1.3 to %1.9 per year. Neither self-citations nor publications in non-ranked journals appears to affect salary.

Severity index for rheumatoid arthritis and its association with health care costs and biologic therapy use in Turkey

Objective: This study aimed to apply the previously validated severity index for rheumatoid arthritis (SIFRA) to prevalent rheumatoid arthritis (RA) groups in Turkey and determine the effect of RA severity on health care costs and biologic use. Methods: This retrospective study used the Turkish national health insurance database MEDULA (June 1, 2009-December 31, 2011). Prevalent RA patients were required to be age 18 to 99, have two RA diagnoses at least 60 days apart and be continuously enrolled 1 year prior to (baseline period) and post (follow-up period) index date, which was the first RA claim during the identification period (June 1, 2010-December 31, 2010). SIFRA was calculated for the baseline period. Total health care costs and biologic use were examined for the follow-up period. The chi-square test was used to determine the association between SIFRA score terciles and outcomes. Generalized linear models were applied to determine health care costs while multivariate logistic regression determined the effect of SIFRA on outcome measures for biologic use. Results: A total of 1,920 patients were identified. The mean SIFRA score was 14.21, and 7.05 (49.57%) of the mean composed of clinical and functional status variables, followed by 6.32 (44.47%) for medications, 0.48 (3.40%) for radiology and laboratory findings, and 0.32 (2.25%) for extra-articular manifestation. There was a significant variation in scores across cities. After controlling for age, gender, region, and comorbidity index, patients in the high SIFRA tercile were 5.16 times more likely to be prescribed biologics (p<0.001, confidence interval [CI]: 3.46-7.69), and incurred annual health care costs that were 2,091 higher (p<0.001, CI: 1,557 - 2,625) than those in the low SIFRA score tercile. Conclusion: RA severity varies throughout Turkey and is a significant determinant of health care costs and biologic therapy use. Therefore, future comparative effectiveness studies should include the severity measure in their analysis

Coronary Angiography Utilization and Costs for Coronary Artery Bypass Graft Surgery Patients in Turkey

INTRODUCTION: To assess excess use of coronary angiography prior to coronary artery bypass graft surgery and its association with mortality, health care costs, and hospital quality in Turkey. METHODS: Using Turkish National Health Insurance Data (2009–2011) that included patients who underwent cardiac surgery, coronary angiography utilization was identified. Propensity score matching was used to compare survival rates and annual health care costs of patients in a coronary angiography excess-use group (>1 angiogram) and in a standard-therapy group (1 angiogram). The empirical Bayesian approach was used to combine mortality and hospital volume for quality index. The relationship between hospital quality and excess use of coronary angiography was assessed using Chi-squared tests. RESULTS: Out of 20,126 patients identified, 7.27% of patients underwent excessive coronary angiography procedures (excess-use group), with an average annual cost at 9.7% higher than those who had a single angiography (standard-therapy group; P < 0.01). Operational mortality associated with excessive use was significantly higher as well (7.4% versus 5.4%, P < 0.02). There exists variation in the use of coronary angiography across cities and hospitals. Patients who underwent cardiac surgery in high-quality hospitals were less likely to have excessive angiography use than those in low-quality hospitals (7.0% versus 9.5%, P < 0.01). CONCLUSION: In Turkey, excess use of coronary angiography prior to coronary artery bypass graft surgery is associated with higher operational mortality, higher expenditures, and lower hospital quality

Benefit Plan Design and Prescription Drug Utilization Among Asthmatics: Do Patient Copayments Matter?

Objective: The ratio of controller to reliever medication use has been proposed as a measure of treatment quality for asthma patients. In this study we examine the effects of plan level mean out-of-pocket asthma medication patient copayments and other features of benefit plan design on the use of controller medications alone, controller and reliever medications (combination therapy), and reliever medications alone. Methods: 1995-2000 MarketScan claims data were used to construct plan-level out-of-pocket copayment and physician/practice prescriber preference variables for asthma medications. Separate multinomial logit models were estimated for patients in fee-for-service (FFS) and non-FFS plans relating benefit plan design features, physician/practice prescribing preferences, patient demographics, patient comorbidities and county-level income variables to patient-level asthma treatment patterns. Results: We find that the controller reliever ratio rose steadily over 1995-2000, along with out-of-pocket payments for asthma medications, which rose more for controllers than for relievers. However, after controlling for other variables, plan level mean out-of-pocket copayments were not found to have a statistically significant influence upon patient-level asthma treatment patterns. On the other hand, physician practice prescribing patterns strongly influenced patient level treatment patterns. Conclusions: There is no strong statistical evidence that higher levels of out-of-pocket copayments for prescription drugs influence asthma treatment patterns. However, physician/practice prescribing preferences influence patient treatment.

Prevalence of Diagnosed Opioid Abuse and its Economic Burden in the Veterans Health Administration

Objective Evaluate prevalence and risk‐adjusted healthcare costs of diagnosed opioid abuse in the national V eterans H ealth A dministration ( VHA ). Costs were compared between patients with and without diagnosed opioid abuse. Design Medical and pharmacy claims analysis of VHA data (10/01/2006 to 09/30/2010) were retrospectively analyzed. Prevalence was calculated as the percent of patients with diagnosed opioid abuse for the entire VHA membership and those with noncancer pain diagnoses, compared between patients prescribed opioids prior to abuse diagnosis and those not prescribed opioids through the VHA system. Healthcare utilization and costs were estimated using matching techniques and generalized linear models to control for clinical and demographic differences between patients with and without diagnosed opioid abuse. Separate comparisons were made (with diagnosed abuse vs. without) for each cohort: patients with/without opioid prescriptions. Results Five‐year diagnosed opioid abuse was 1.11%. Among patients prescribed opioids, 5‐year abuse prevalence was 3.04%. Pain patients prescribed opioids had the highest abuse rate at 3.26%. Adjusted annual healthcare costs for diagnosed opioid abuse patients were higher than for those without diagnosed abuse, (prescribed opioids overall healthcare costs: $28,882, with diagnosed abuse vs.$13,605 for those without; not prescribed opioids: $25,197 vs.$6350, P ‐value< 0.0001; opioid‐specific healthcare costs for patients prescribed opioids: $8956 vs.$218; patients not prescribed opioids: $8733 vs.$20). Conclusions Diagnosed opioid abuse prevalence is almost 7‐fold higher in the veteran's administration population than in commercial health plans and translates to a significant economic burden. Appropriate interventions should be considered to prevent and reduce opioid abuse.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/107356/1/papr12097.pd

Differences in Healthcare Utilization and Associated Costs Between Patients Prescribed vs. Nonprescribed Opioids During an Inpatient or Emergency Department Visit

Objectives Compare healthcare resource utilization ( HCRU ) and costs between patients prescribed opioids ( R x OP ) and those who were not ( N o R x OP ) during an emergency department ( ED ) or inpatient visit. Methods Retrospective cohort analysis was performed ( J anuary 2006 to S eptember 2010). Continuously eligible R x OP patients in ED /inpatient settings ( J anuary 2007 to S eptember 2009) were included if age was ≥ 12 years by initial prescription date (or random date between first ED /inpatient admission and S eptember 30, 2009 [ N oRx OP patients]). Healthcare resource utilization and costs for 12 months after initial prescription were compared. Univariate descriptive analyses were performed for baseline and outcome variables and compared using appropriate tests. Risk adjustment compared HCRU between R x OP and N o R x OP cohorts for the postindex period. Results Of 27,599 eligible patients, R x OP patients ( n  = 18,819) were younger, less likely to be male, more likely to reside in southern U nited S tates and to have Preferred Provider Organization health plans, and had lower comorbidity index scores, compared with N o R x OP patients ( n  = 8,780). R x OP patients were less likely to have nonpain‐related comorbidities and more frequently diagnosed with pain‐related comorbidities. Unmatched and propensity‐matched R x OP patients experienced higher HCRU and costs in all subcategories (total, inpatient, outpatient ED , physician, pharmacy, other outpatient settings). Opioid abuse frequency was low in patients with common diagnoses/procedures within 3 months before initial prescription (0.48%). Average time to abuse was < 1 year (201 days). Conclusion Most patients were prescribed opioids initially during ED /inpatient visits and incurred higher HCRU than those not prescribed opioids. Among those with diagnosed opioid abuse after initiating opioids, time to diagnosis was rapid (range: 14 to 260 days) for patients with common diseases and procedures.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/107375/1/papr12098.pd

Estimation from censored medical cost data

Thesis (Ph. D.)--Michigan State University. Department of Economics, 2002Includes bibliographical references (pages 69-72