Table 2.
Main results: Effects of chronic care management intervention for substance dependence on, favorable addiction status (1-category improvement in addiction severity index), substance use related problems, health related quality of life and acute healthcare utilization1,2
| BASELINE | 12-MONTH FOLLOW-UP | |||||
|---|---|---|---|---|---|---|
| Outcome | Intervention | Control | Intervention | Control | Parameter† and 95% confidence interval | p |
| All participants | n=282 | n=281 | n=270 | n=262 | n=553 | |
| Abstinence from stimulants, opioids, and heavy drinking, past 30 days (No. (%)) | *** | *** | 120 (44%) | 109 (42%) | OR 0.84 (0.65, 1.10) § | 0.21 |
| Abstinence from stimulants, opioids, and any drinking, past 30 days (No. (%)) | *** | *** | 109 (40%) | 95 (36%) | OR 0.89 (0.68, 1.17) § | 0.40 |
| Alcohol Addiction Severity Index score > 0.4* (No. (%)) | 170 (60%) | 175 (63%) | 53 (20%) | 58 (22%) | OR 1.01 (0.78, 1.31) ¥ | 0.93 |
| Drug Addiction Severity Index score >0.2** (No. (%)) | 205 (73%) | 208 (74%) | 58 (21%) | 54 (21%) | OR 0.90 (0.71, 1.14) ¥ | 0.38 |
| Mental health related quality of life (MCS score)(mean (95% CI)) | 30.8 (29.7, 31.9) | 30.0 (28.8, 31.2) | 39.4 (38.3, 40.5) | 39.1 (37.9, 40.3) | β (95% CI) −0.14 (−1.49, 1.21) ¤ | 0.84 |
| Physical health related quality of life (PCS score)(mean (95% CI)) | 41.4 (40.4, 42.4) | 42.0 (41.0, 42.9) | 43.1 (42.2, 44.0) | 42.4 (41.5, 43.4) | β (95% CI) 0.48 (−0.70, 1.66) ¤ | 0.42 |
| Any nights in hospital (medical, psychological, detox) past 3 months (No. (%)) | 76 (27%) | 84 (30%) | 46 (17%) | 39 (15%) | OR 1.07 (0.78, 1.46) § | 0.67 |
| Any days in emergency department past 3 months (No. (%)) | 146 (52%) | 158 (56%) | 81 (30%) | 80 (31%) | OR 0.96 (0.74, 1.23) § | 0.73 |
| Alcohol dependence subgroup | n=206 | n=207 | n=199 | n=195 | n=409 | |
| Abstinence from heavy drinking, past 30 days (No. (%)) | *** | *** | 109 (55%) | 97 (50%) | OR 1.05 (0.78, 1.43) § | 0.74 |
| Number of heavy drinking days in past 30 days (mean (95% CI)) | 17.4 (15.9, 18.8) | 18.6 (17.2, 20.0) | 5.1 (3.8, 6.4) | 5.7 (4.4, 7.1) | IRR 0.95 (0.73, 1.23) # | 0.69 |
| Alcohol related problem score (mean (95% CI)) | 25.1 (23.3, 26.9) | 26.4 (24.7, 28.1) | 10.4 (8.5, 12.3) | 13.1 (11.0, 15.1) | IRR 0.85 (0.72, 1.00) # | 0.048 |
| Alcohol Addiction Severity Index score > 0.4* (No. (%)) | 168 (82%) | 173 (84%) | 53 (27%) | 57 (29%) | OR 1.08 (0.80, 1.45) ¥ | 0.62 |
| Mental health related quality of life (MCS score) (mean (95% CI)) | 31.2 (29.9, 32.5) | 30.0 (28.6, 31.4) | 39.8 (38.5, 41.1) | 38.7 (37.2, 40.1) | β (95% CI) 0.47 (−1.08, 2.02) ¤ | 0.55 |
| Physical health related quality of life (PCS score) (mean (95% CI)) | 41.7 (40.6, 42.9) | 41.6 (40.4, 42.7) | 43.1 (42.1, 44.1) | 42.0 (40.8, 43.2) | β (95% CI) 1.06 (−0.29, 2.40) ¤ | 0.12 |
| Any nights in hospital (medical, psychological, detox) past 3 months (No. (%)) | 59 (29%) | 67 (32%) | 40 (20%) | 35 (18%) | OR 1.06 (0.74, 1.50) § | 0.76 |
| Any days in emergency department past 3 months (No. (%)) | 108 (52%) | 121 (58%) | 61 (31%) | 58 (30%) | OR 1.00 (0.74, 1.35) § | 0.99 |
| Drug dependence subgroup | n=233 | n=232 | n=224 | n=217 | n=458 | |
| Abstinence from stimulants and opioids, past 30 days (No. (%)) | *** | *** | 117 (52%) | 111 (51%) | OR 0.85 (0.64, 1.14) § | 0.28 |
| Drug related problem score (mean (95% CI)) | 32.1 (30.7, 33.4) | 33.3 (32.1, 34.5) | 15.6 (13.6, 17.7) | 16.0 (13.8, 18.1) | IRR 1.03 (0.92, 1.16) # | 0.62 |
| Drug Addiction Severity Index score >0.2** (No. (%)) | 202 (87%) | 204 (88%) | 57 (25%) | 54 (25%) | OR 0.87 (0.67, 1.12) ¥ | 0.27 |
| Mental health related quality of life (MCS score) (mean (95% CI)) | 30.3 (29.1, 31.5) | 29.6 (28.4, 30.8) | 39.1 (37.8, 40.4) | 39.1 (37.8, 40.4) | β (95% CI) −0.65 (−2.14, 0.84) ¤ | 0.39 |
| Physical health related quality of life (PCS score) (mean (95% CI)) | 41.3 (40.2, 42.4) | 42.3 (41.2, 43.3) | 43.3 (42.3, 44.3) | 42.7 (41.7, 43.7) | β (95% CI) 0.23 (−1.04, 1.50) ¤ | 0.72 |
| Any nights in hospital (medical, psychological, detox) past 3 months (No. (%)) | 60 (26%) | 59 (25%) | 38 (17%) | 28 (13%) | OR 1.18 (0.83, 1.66) § | 0.35 |
| Any days in emergency department past 3 months (No. (%)) | 115 (49%) | 129 (56%) | 68 (30%) | 67 (31%) | OR 0.86 (0.66, 1.14) § | 0.30 |
Analyses were adjusted for dependence type (alcohol, drug or both, the randomization stratification variable) and time
ASI=Addiction Severity Index
CI=confidence interval
MCS=Mental Component Summary scale score of the 12-item Short Form Health Survey (SF-12)
PCS=Physical Component Summary scale score of the 12-item Short Form Health Survey (SF-12)
Alcohol and drug related problems assessed by the Short Inventory of Problems (SIP) and SIP-Drug (SIP-D)
Alcohol ASI score >0.4 represents the top two of five ordered categories used for analysis. Odds ratio is for a 1-category improvement (i.e. lower ASI alcohol score) in alcohol addiction severity
Drug ASI score >0.2 represents the top two of five ordered categories used for analysis. Odds ratio is for a 1-category improvement (i.e. lower ASI drug score) in drug addiction severity
All participants reported recent substance use at baseline
OR (odds ratio) and (95% confidence interval, CI) from Generalized Estimating Equations (GEE) logistic regression model
OR (95% CI) from GEE proportional odds regression model predicting a lower addiction severity score category
β (mean difference) between randomized groups (95% CI) from linear mixed effects regression model
IRR (incidence rate ratio) (95% CI) from GEE overdispersed Poisson regression model
Corresponds to the main effect of the intervention in models that do not include interaction terms
Results of analyses adjusting for race and depressive symptoms were similar.
Exploratory analyses suggested an interaction between intervention and time (p=0.05) for the outcome abstinence from drugs and heavy drinking, but not in any hypothesized direction: the intervention group had lower odds of abstinence (drugs and heavy drinking) at 3 months (AOR 0.69, 95% CI 0.48–0.99), but no significant differences were observed at 6 or 12 months. No other outcomes had a statistically significant intervention by time interaction.