Interruptions in Medicaid Coverage and Risk for Hospitalization for Ambulatory Care–Sensitive Conditions

doi:10.1059/0003-4819-149-12-200812160-00004

Interruptions in Medicaid Coverage and Risk for Hospitalization for Ambulatory Care–Sensitive Conditions

From San Francisco General Hospital and University of California, San Francisco, San Francisco, California.

Abstract

Background: Many low-income U.S. citizens experience interruptions in health insurance coverage.

Objective: To determine the rate of hospitalization for ambulatory care–sensitive conditions among Medicaid beneficiaries with interruptions in coverage.

Design: Retrospective cohort study.

Setting: California Medicaid population.

Patients: 4 735 797 adults in California age 18 to 64 years who received a minimum of 1 month of Medicaid coverage between 1998 to 2002.

Measurement: Time to hospitalization for an ambulatory care–sensitive condition.

Results: Sixty-two percent of Medicaid beneficiaries experienced at least 1 interruption in coverage during the study period. The 3 most common ambulatory care–sensitive conditions resulting in a hospitalization were heart failure, diabetes, and chronic obstructive pulmonary disease. Interruptions in coverage were associated with a higher risk for hospitalization for an ambulatory care–sensitive condition (adjusted hazard ratio, 3.66 [95% CI, 3.59 to 3.72]; P < 0.001). In subgroup analyses, the association between interrupted coverage and hospitalization was stronger for beneficiaries eligible through the Temporary Aid to Needy Families program (adjusted hazard ratio, 8.56 [CI, 8.06 to 9.08]) than for beneficiaries eligible through the Supplemental Security Income program (adjusted hazard ratio, 1.72 [CI, 1.67 to 1.76]), who typically retain Medicare coverage even when their Medicaid coverage is interrupted.

Limitation: The study lacked information on why interruptions occurred and whether beneficiaries with interruptions transitioned to other insurance coverage.

Conclusion: Interruptions in Medicaid coverage are associated with a higher rate of hospitalization for ambulatory care–sensitive conditions. Policies that reduce the frequency of interruptions in Medicaid coverage might prevent some of the health events that trigger hospitalization and high-cost health care spending.

Article and Author Information

Disclaimer: The views presented here are those of the authors and are not necessarily those of The Commonwealth Fund, its director, officers, or staff.
Acknowledgment: The authors thank the California Department of Health Care Services and the California Office of Statewide Health Planning and Development, who provided the linked data set used in this analysis; Professor Eric Vittinghof in the Department of Epidemiology and Biostatistics at the University of California, San Francisco, for his helpful comments in reviewing our analytic plan; and Lauren Davidson for her assistance in preparing this manuscript for publication.
Grant Support: By The Commonwealth Fund, a national, private foundation that supports independent research on health and social issues.
Potential Financial Conflicts of Interest: None disclosed.
Reproducible Research Statement: Study protocol and statistical code: Available from Dr. Bindman (e-mail, abindman{at}medsfgh.ucsf.edu). Data set: Available by request from the California Department of Health Care Services.
Corresponding Author: Andrew B. Bindman, MD, Building 10, Ward 13, San Francisco General Hospital, 1001 Potrero Avenue, San Francisco, CA 94110; e-mail, abindman{at}medsfgh.ucsf.edu.
Current Author Addresses: Drs. Bindman and Chattopadhyay: San Francisco General Hospital, Building 10, Ward 13, 1001 Potrero Avenue, San Francisco, CA 94110.
Ms. Auerback: University of California, San Francisco, 1600 Divisadero Street, MZ Bldg B B-718, San Francisco, CA 94143-1297.
Author Contributions: Conception and design: A.B. Bindman, A. Chattopadhyay.
Analysis and interpretation of the data: A.B. Bindman, A. Chattopadhyay.
Drafting of the article: A.B. Bindman, A. Chattopadhyay, G.M. Auerback.
Critical revision of the article for important intellectual content: A.B. Bindman, A. Chattopadhyay.
Final approval of the article: A.B. Bindman, A. Chattopadhyay, G.M. Auerback.
Statistical expertise: A. Chattopadhyay.
Obtaining of funding: A.B. Bindman.
Administrative, technical, or logistic support: A. Chattopadhyay, G.M. Auerback.
Collection and assembly of data: A. Chattopadhyay, G.M. Auerback.