Table 2. Association of Partner Medicare Advantage (MA) Enrollment Status Change and Other Respondent and Plan Characteristics With Respondent Enrollment Status Changea.
| Characteristic | Respondent MA enrollment status change | |||||
|---|---|---|---|---|---|---|
| Predicted probability, % (95% CI) | Marginal effects, percentage points (95% CI) | |||||
| Remained in same MA plan | Switched to another MA plan | Disenrolled from MA to FFS | Remained in same MA plan | Switched to another MA plan | Disenrolled from MA to FFS | |
| Partner MA enrollment status change | ||||||
| Remained in same MA plan | 95.7 (94.6-96.9) | 3.5 (2.4-4.6) | 0.8 (0.3-1.2) | [Reference] | [Reference] | [Reference] |
| Switched to another MA plan | 28.2 (20.7-35.7) | 70.8 (63.3-78.4) | 0.9 (0.1-1.8) | −67.5 (−75.3 to −59.8)b | 67.3 (59.6 to 75.1)b | 0.2 (−0.8 to 1.1) |
| Disenrolled from MA to FFS | 33.7 (18.9-48.5) | 8.3 (2.0-14.5) | 58.0 (43.0-73.1) | −62.0 (−77.0 to −47.1)b | 4.8 (−1.6 to 11.1) | 57.3 (42.1 to 72.5)b |
| Sex | ||||||
| Female | 79.5 (77.2-81.8) | 17.9 (15.7-20.1) | 2.6 (1.6-3.5) | −0.4 (−2.5 to 1.8) | 0.0 (−2.1 to 2.1) | 0.3 (−0.5 to 1.2) |
| Male | 79.9 (77.5-82.3) | 17.9 (15.6-20.2) | 2.2 (1.3-3.1) | [Reference] | [Reference] | [Reference] |
| Age, y | ||||||
| 65-74 | 80.5 (78.0-82.9) | 17.4 (15.0-19.8) | 2.1 (1.1-3.1) | [Reference] | [Reference] | [Reference] |
| 75-84 | 78.5 (76.1-81.0) | 19.0 (16.6-21.3) | 2.5 (1.6-3.4) | −1.9 (−4.4 to 0.5) | 1.6 (−0.8 to 4.0) | 0.4 (−0.5 to 1.3) |
| ≥85 | 80.8 (76.5-85.2) | 16.4 (12.2-20.5) | 2.8 (1.4-4.2) | 0.4 (−4.1 to 4.9) | −1.0 (−5.4 to 3.3) | 0.7 (−0.8 to 2.1) |
| Nursing home resident | ||||||
| No | 79.7 (77.6-81.8) | 17.9 (15.9-19.9) | 2.4 (1.5-3.2) | [Reference] | [Reference] | [Reference] |
| Yes | 79.8 (71.8-87.8) | 17.3 (9.7-24.8) | 2.9 (−0.2 to 6.0) | 0.1 (−7.8 to 8.1) | −0.6 (−8.1 to 6.9) | 0.5 (−2.7 to 3.7) |
| Medicare-Medicaid dual eligibility | ||||||
| No | 80.3 (78.2-82.4) | 17.6 (15.6-19.7) | 2.1 (1.3-2.9) | [Reference] | [Reference] | [Reference] |
| Yes | 73.0 (66.3-79.7) | 21.9 (15.6-28.1) | 5.1 (2.5-7.8) | −7.3 (−14.0 to −0.6)c | 4.3 (−2.0 to 10.5) | 3.0 (0.5 to 5.6)c |
| Limitations in activities of daily living | ||||||
| 0 | 79.2 (77.0-81.4) | 17.8 (15.8-19.9) | 3.0 (1.8-4.1) | [Reference] | [Reference] | [Reference] |
| 1-2 | 79.8 (76.5-83.1) | 18.9 (15.7-22.1) | 1.3 (0.3-2.4) | 0.6 (−2.6 to 3.8) | 1.1 (−2.0 to 4.1) | −1.6 (−3.1 to −0.2)c |
| 3-6 | 83.0 (77.6-88.5) | 15.0 (9.6-20.3) | 2.0 (0.8-3.2) | 3.8 (−1.7 to 9.3) | −2.9 (−8.2 to 2.4) | −1.0 (−2.5 to 0.5) |
| Limitations in instrumental activities of daily living | ||||||
| 0 | 79.1 (76.7-81.6) | 19.2 (16.8-21.6) | 1.7 (0.9-2.4) | [Reference] | [Reference] | [Reference] |
| 1-2 | 81.0 (76.0-86.1) | 14.0 (9.6-18.5) | 4.9 (1.2-8.7) | 1.9 (−3.7 to 7.5) | −5.2 (−10.4 to 0.0) | 3.3 (−0.3 to 6.9) |
| 3-5 | 77.3 (64.6-90.0) | 8.9 (3.0-14.8) | 13.8 (−0.2 to 27.8) | −1.8 (−14.8 to 11.2) | −10.3 (−16.9 to −3.6)d | 12.1 (−1.9 to 26.1) |
| Hospitalization in the past 2 years | ||||||
| No | 79.6 (77.4-81.8) | 17.9 (15.7-20.0) | 2.5 (1.6-3.4) | [Reference] | [Reference] | [Reference] |
| Yes | 79.9 (77.2-82.7) | 18.0 (15.3-20.6) | 2.1 (1.1-3.1) | 0.3 (−2.3 to 2.9) | 0.1 (−2.4 to 2.6) | −0.4 (−1.4 to 0.6) |
| MA plan star rating | ||||||
| Unrated | 81.3 (75.3-87.4) | 16.7 (10.9-22.5) | 2.0 (0.8-3.1) | 3.3 (−4.7 to 11.2) | −1.3 (−8.7 to 6.2) | −2.0 (−4.4 to 0.5) |
| 2-2.5 | 78.1 (72.5-83.7) | 18.0 (13.0-23.0) | 3.9 (1.4-6.5) | [Reference] | [Reference] | [Reference] |
| 3-3.5 | 74.0 (70.6-77.5) | 21.3 (18.4-24.1) | 4.7 (2.4-7.1) | −4.1 (−9.7 to 1.6) | 3.3 (−1.7 to 8.3) | 0.8 (−2.1 to 3.7) |
| 4-5 | 83.4 (81.0-85.9) | 15.6 (13.1-18.0) | 1.0 (0.2-1.7) | 5.4 (−0.6 to 11.3) | −2.4 (−7.7 to 2.9) | −3.0 (−5.8 to −0.1)c |
| MA plan market share in the county, by tertiles | ||||||
| 0%-4.7% | 77.4 (74.6-80.1) | 20.5 (17.8-23.2) | 2.2 (1.2-3.1) | [Reference] | [Reference] | [Reference] |
| 4.8%-15.1% | 80.3 (77.7-82.9) | 16.9 (14.5-19.3) | 2.8 (1.5-4.1) | 2.9 (0.0 to 5.9)c | −3.6 (−6.4 to −0.8)c | 0.6 (−0.6 to 1.9) |
| 15.2%-100% | 81.9 (79.2-84.5) | 15.8 (13.3-18.3) | 2.3 (1.3-3.4) | 4.5 (1.5 to 7.5)d | −4.7 (−7.6 to −1.7)d | 0.2 (−0.8 to 1.2) |
We used multinomial logistic regression to model respondent changes in MA enrollment during the observation year: remaining in the same plan, switching to another MA plan, and disenrolling to fee-for-service (FFS) Medicare. Covariates included partner’s MA enrollment change; respondent demographic, socioeconomic, and health characteristics; and MA plan characteristics presented in Table 1, with respondent education, total family income, number of family and unpaid caregivers, metropolitan statistical area, comorbidities, and year fixed effects. To facilitate interpretation, we calculated the mean predicted probability of MA plan enrollment change associated with each characteristic using estimates from the multinomial logistic regression and calculated the average marginal effects for each characteristic to compare whether the predicted probabilities of MA plan enrollment change differed by each characteristic. Data were weighted using the Health and Retirement Study analytic weights; Stata svy commands were used to incorporate strata of the sample design and clustering around dyads to account for correlation within dyads that were observed twice when calculating SEs of the estimates. For brevity, we report a subset of factors; other factors were either not associated with MA plan enrollment change or had very small marginal effects for the outcome.
P < .001. cP < .05. dP < .01.