Study | Key findings | Confounders controlled for |
---|---|---|
Adams, Soumerai, & Ross-Degnan, 2001a | high income > good insurance > lower OOPP > higher drug consumption | none |
Blustein, 1995a | low income > less probability of mammography | age, race, education, self-rated health status, total Medicare Part B reimbursement in 1991, smoking status, living arrangement |
Chandra et al., 2007 | low income > high price elasticity > increased hospital visits due to less prevention | type of insurance plan, age, spending tercile, Charlson Index, health status |
Crystal, Johnson, Harman, Sambamoorthi, & Kumar, 2000b | average OOPP burden: 19% (lowest quintile: 31.5%, top quintile: 8.5%) | sex, race, age, education, marital status, self-reported health status, number of medical conditions, number of ADL & IADL impairments, insurance coverage |
Davis, Poisal, Chulis, Zarabozo, & Cooper, 1999a | high income > best insurance > lowest OOPP | none |
Dowd et al., 1994a | high income > best insurance > lowest OOPP | age, sex, marital status, education, living arrangements, number & proximity of living children, health insurance, self-reported health condition |
Fahlman, Lynn, Doberman, Gabel, & Finch, 2006d | high income > high utilization & OOPP | race, sex, Charlson Index, age, insurance type |
Gellad, Huskamp, Phillips, & Haas, 2006a | Medicare Part D > general cost decline, but: high incomes advantaged through lower burden in Donut Hole | race, chronic conditions, insurance coverage |
Goldman & Zissimopoulos, 2003b | high income > high absolute OOPP, but lower burden (highest quartile: 1% OOPP of income, lowest: 17% (up to 43%); hardest hit: those shortly above limit of Medicaid support) | none |
Guidry, Aday, Zhang, & Winn, 1998b | disadvantages for minorities (lower income, bad insurance, higher costs, less treatments) | none |
Klein, Turvey, & Wallace, 2004i | low income > bad insurance > high OOPP > less prevention > more illnesses > more OOPP > more cost-reducing strategies > high follow-up costs (each +100$/month OOPP > +10% of unregular use) | none |
Miller & Champion, 1993a | high income > high utilization & drug adherence | none |
Mitchell, Mathews, Hunt, Cobb, & Watson, 2001a | less income > less medication adherence due to OOPP > worse health status & less health consciousness > higher OOPP > less adherence | age, race, education, residential status, health status, medication profile |
Mojtabai & Olfson, 2003c | lower income > less adherence | age, sex, race, education, marital status, employment, insurance coverage |
Pourat, Rice, Kominski, & Snyder, 2000d | low income > less supplemental prescription drug coverage > high OOPP | none |
Rector & Venus, 2004a | low income > more cost induced delay or stop of medication utilization (<$1000 monthly household income: 38%, >$4000: 17%) | none |
Riley, 2008b | 1992-2004: absolute OOPP up by 22.5%; highest burden: second lowest quartile > no Medicaid | none |
Rogowski, Lillard, & Kington, 1997b | low income > higher expenditures & higher burden: 5,4-5,9%, middle income: 1.6%, highest income: 0,6%; insurance coverage reduces amount spent by 50%; cost distribution highly skewed: 55% spend 1% or less, 1% spend 25% of yearly income | age, sex, race, education, residential status, marital status, insurance coverage, health status |
Sambamoorthi, Shea, & Crystal, 2003b | Absolute OOPP nearly equal, but: low income > higher burden (+10% burden: <200% of poverty level: 13.4%, >200%: 2.4%) | sex, race, age, education, marital status, insurance coverage, self-rated health status, place of residence |
Saver, Doescher, Jackson, & Fishman, 2004d | high income > higher probability of drug benefit (25% vs. 17%) > more adherence | age, race, sex, education, household configuration, insurance coverage, self-rated health status |
Selden & Banthin, 2003b | lower income > higher burden: +40% burden 1987 (1996) (below poverty line: 20.9% (19.6%), >200% of p.l.: 3.8% (4.8%)) | none |
Soumerai et al., 2006a | low income > less drug adherence (<$10.000 yearly income: 14.5%, >$40.000: 8.7%) | sex, age, race, education, self-rated health status, insurance coverage |