Table 1.
Plan Summary Statistics and Refusal and Attrition Rates
| Plan (1) | Individuals (Families) (2) | Avg. out-of- pocket sharec (3) | Share Refusing Enrollment (4) | Share Attriting (5) | Share Refusing or Attriting (6) |
|---|---|---|---|---|---|
| Free Care | 1,894 (626) | 0% | 6% | 5% | 12% |
| 25% Coinsurance | 647 (224) | 23% | 20% | 6% | 26% |
| Mixed Coinsurancea | 490 (172) | 28% | 19% | 9% | 26% |
| 50% Coinsurance | 383 (130) | 44% | 17% | 4% | 21% |
| Individual Deductibleb | 1,276 (451) | 59% | 18% | 13% | 28% |
| 95% Coinsurance | 1,121 (382) | 76% | 24% | 17% | 37% |
| All Plans | 5,811 (1,985) | 34% | 16% | 10% | 24% |
| p-value, all plans equal | < 0.0001 | < 0.0001 | < 0.0001 | ||
| p-value, Free Care vs. 95% | < 0.0001 | < 0.0001 | < 0.0001 | ||
| p-value, Free Care vs. 25% | 0.0001 | 0.5590 | 0.0001 | ||
| p-value, 25% vs. 95% | 0.4100 | 0.0003 | 0.0136 |
Table Notes: “Coinsurance rate” refers to the share of the cost that is paid by the individual. In the 25%, mixed, 50%, and 95% coinsurance rate plans, families were assigned out-of-pocket maximums of 5%, 10%, or 15% of family income, up to a limit of $750 or $1,000. In the individual deductible plan, the out-of-pocket maximum was $150 per-person up to a maximum of $450 per family. The sample counts for the 95% coinsurance rate plans include 371 individuals who faced a 100% coinsurance rate in the first year of the experiment. Refusal and attrition rates are regression-adjusted for site and contact month fixed effects and interactions, because plan assignment was random only conditional on site and month of enrollment (see Newhouse et al. 1993, Appendix B). “Contact month” refers to the month in which the family was first contacted by the experiment and is used in lieu of month of enrollment because month of enrollment is available only for individuals who agreed to enroll. Refusal and attrition rates exclude the experiment’s Dayton site (which accounted for 1,137 enrollees) because data on Dayton refusers were lost. An individual is categorized as having attrited if he leaves the experiment at any time prior to completion.
The “Mixed Coinsurance” plan had a coinsurance rate of 50% for dental and outpatient mental health services, and a coinsurance rate of 25% for all other services.
The “Individual Deductible” plan had a coinsurance rate of 95% for outpatient services and 0% for inpatient services.
To compute the average out-of-pocket share we compute the ratio of out-of-pocket expenses to total medical expenditure for each enrollee, and report the average ratio for each plan.