TABLE 2.
Differences in outpatient utilization for Primary care Intensive Management (PIM) relative to usual primary care
| Primary care Intensive Management (PIM) (N = 1901) | Usual primary care (N = 1882) | Incidence rate ratio (SEM) a | ||||
|---|---|---|---|---|---|---|
| Types of outpatient care, visits per year | 12 months pre‐randomization Mean (SD) | 13‐24 months post‐randomization Mean (SD) | 12 months pre‐randomization Mean (SD) | 13‐24 months post‐randomization Mean (SD) | D‐D Estimate a | p value |
| Primary care Intensive Management | 0 (0) | 3.05 (8.51) | 0 (0) | 0 (0) | NA | |
| In person VHA encounters | ||||||
| Emergency Department | 2.72 (2.59) | 1.81 (2.87) | 2.73 (2.41) | 1.78 (2.68) | 1.03 (0.04) | 0.427 |
| Triage | 1.63 (2.95) | 1.31 (2.6) | 1.44 (2.66) | 1.28 (2.48) | 0.89 (0.05) | 0.031 |
| Observation | 0.17 (0.44) | 0.09 (0.36) | 0.14 (0.47) | 0.08 (0.32) | 0.98 (0.15) | 0.91 |
| Urgent care | 0.02 (0.2) | 0.03 (0.33) | 0.02 (0.16) | 0.01 (0.18) | 1.31 (0.57) | 0.529 |
| Primary care | 4.79 (5.86) | 4.58 (7.15) | 4.81 (4.52) | 3.73 (4) | 1.16 (0.04) | <0.001 |
| Women's health | 0.22 (1.1) | 0.23 (1.13) | 0.28 (1.35) | 0.22 (1.1) | 1.25 (0.16) | 0.079 |
| Geriatrics | 0.12 (0.83) | 0.13 (0.77) | 0.13 (1.08) | 0.14 (1) | 0.9 (0.22) | 0.678 |
| Home‐based primary care | 0.28 (2.38) | 0.79 (5.6) | 0.27 (2.16) | 0.59 (3.83) | 1.18 (0.32) | 0.549 |
| Medical/surgical specialty | 10.64 (14.3) | 9.49 (14.33) | 11.14 (16) | 10.43 (18.53) | 1.02 (0.03) | 0.537 |
| Mental health, substance use treatment | 8.78 (22.64) | 7.62 (21.12) | 9.37 (24.26) | 7.86 (20.86) | 1.14 (0.06) | 0.021 |
| Mental health intensive case management | 0.08 (2.36) | 0.2 (4.08) | 0.05 (1.49) | 0.18 (2.95) | 0.26 (0.19) | 0.061 |
| Social work | 0.2 (1.16) | 0.15 (0.72) | 0.17 (0.78) | 0.19 (1.25) | 0.92 (0.15) | 0.622 |
| Housing services | 2.23 (9.3) | 1.78 (8.07) | 2.45 (9.44) | 1.78 (6.88) | 1.33 (0.15) | 0.009 |
| Case management | 0.08 (0.4) | 0.07 (0.37) | 0.08 (0.37) | 0.02 (0.19) | 3.11 (0.78) | <0.001 |
| Home visits | 0.09 (0.65) | 0.3 (1.76) | 0.07 (0.55) | 0.1 (1.09) | 2.58 (0.7) | <0.001 |
| Rehabilitation therapies | 2.43 (5.75) | 2.2 (5.49) | 2.66 (6.31) | 2.37 (5.66) | 0.95 (0.06) | 0.453 |
| Palliative care, hospice | 0.01 (0.16) | 0.03 (0.39) | 0.03 (0.46) | 0.05 (0.39) | 1.58 (1.12) | 0.519 |
| Clinical pharmacy | 2.37 (15.26) | 1.66 (9.26) | 1.72 (7.98) | 1.32 (6.15) | 1.02 (0.07) | 0.764 |
| Long‐term care (nursing home, adult day health care) | 0.23 (5.02) | 0.29 (5.73) | 0.11 (3.79) | 0.08 (0.87) | 1.37 (0.65) | 0.508 |
| Other (dental, procedures, labs, diagnostic imaging) | 17.98 (18.27) | 14.15 (15.71) | 17.58 (15.38) | 13.9 (15.15) | 1.02 (0.03) | 0.503 |
| Telephone VHA encounters | ||||||
| Primary care | 3.46 (4.02) | 3.5 (5.17) | 3.55 (4.13) | 2.91 (4.2) | 1.18 (0.05) | <0.001 |
| Geriatrics | 0.06 (0.48) | 0.25 (1.49) | 0.07 (0.54) | 0.12 (0.88) | 1.92 (0.48) | 0.009 |
| Mental health, substance use | 0.65 (1.95) | 0.59 (2.05) | 0.71 (2.08) | 0.66 (2.36) | 1.08 (0.1) | 0.431 |
| Medical/surgical specialty | 0.35 (0.93) | 0.33 (1) | 0.36 (1.01) | 0.35 (1.16) | 1.05 (0.11) | 0.631 |
| Housing services | 0.48 (2.46) | 0.48 (2.69) | 0.82 (4.04) | 0.6 (2.86) | 1.14 (0.18) | 0.401 |
| Case management | 0.04 (0.52) | 0.28 (1.58) | 0.04 (0.52) | 0.06 (0.79) | 5.12 (1.84) | <0.001 |
| Telehealth | 1.52 (8.03) | 1.25 (5.55) | 1.35 (5.76) | 0.91 (4.48) | 1.55 (0.25) | 0.007 |
| Total VHA outpatient counts | 60.39 (50.76) | 52.68 (50.5) | 61.22 (48.54) | 50.88 (48.74) | 1.08 (0.03) | 0.002 |
| Total VHA‐covered outpatient counts in community | 8.96 (37.01) | 10.22 (41.77) | 7.87 (32.79) | 8.43 (37.02) | 1.03 (0.1) | 0.775 |
| Total VHA and VHA‐covered outpatient counts | 72.39 (64.7) | 62.9 (68.74) | 72.1 (59.87) | 59.31 (63.38) | 1.08 (0.03) | 0.005 |
Abbreviations: DID, difference in differences; PIM, Primary care Intensive Management; SEM, SE of the mean; VHA, Veterans Health Administration.
a
Difference‐in‐differences (DID) comparing 12 months before vs 13 to 24 months after randomization. The estimates were obtained from negative binomial models predicting utilization with covariates for year, interaction between intervention group and time, Charlson Comorbidity Index score, and patient fixed effects. Incidence rate ratio represents the difference in utilization rate for the intensive management group relative to the usual group.
Significant p values (< 0.05) are in bold.