Table 2.
Clinical characteristics
| Variables | Low dose group (LDG) (n = 200) | Medium dose group (MDG) (n = 273) | High dose group (HDG) (n = 140) | Total sample (N = 613) | p value |
|---|---|---|---|---|---|
| Specialized centers, n (%)a | 114 (57.0) | 189 (69.2) | 104 (74.3) | 407 (66.4) | p < 0.01 |
| Methadone dose mg/ day, mean (SD)b | 35.0 (±12.1) | 81.3 (±14.8) | 150.0 (±33.3) | 81.9 (±46.6) | p < 0.001 |
| Prescribed comedication, n (%)c | 77 (38.7) | 164 (60.1) | 108 (77.1) | 349 (57.0) | p < 0.001 |
| Allowed take-home days per week, mean (SD)d | 5.8 (±3.7) | 5.1 (±3.2) | 4.5 (±2.7) | 5.2 (±3.3) | p < 0.001 |
| Length of stay in MMT, mean (SD), ye | 9.3 (±4.5) | 10.2 (±4.7) | 11.3 (±4.8) | 10.2 (±4.7) | p < 0.001 |
| No. of consultations within 6 months, mean (SD)f | 5.9 (±4.2) | 6.2 (±4.2) | 7.7 (±6.7) | 6.4 (±4.9) | p < 0.01 |
| Alcohol use in the past 30 days, mean (SD)g | 7.4 (±11.1) | 8.9 (±11.1) | 11.8 (±13.3) | 9.1 (±12.1) | p < 0.01 |
| Cannabis use in the past 30 days, mean (SD)h | 8.5 (±12.1) | 8.9 (±12.0) | 11.8 (±13.3) | 8.3 (±11.2) | p > 0.05 |
Significance level p < 0.05.
aSignificant difference between patients in the LDG, MDG and HDG (Kruskal-Wallis test; χ2 = 12.782; df = 2; p < 0.01). The Mann Whitney test revealed that patients in the LDG were significantly more often treated in office-based settings than patients in the MDG (Z = −2.736; p < 0.01) or in the HDG (Z = −3.266; p < 0.001).
bSignificant difference between patients in the LDG, MDG and HDG for prescribed methadone dose (ANOVA; F(2,610) = 1343.158; p < 0.001).
cSignificant difference between patients in the LDG, MDG and HDG (Kruskal-Wallis test; χ2 = 51.360; df = 2; p < 0.001). The Mann Whitney test revealed that patients in the LDG had a significantly lower proportion of prescribed comedication than patients in the MDG (Z = −4.584; p < 0.001) or in the HDG (Z = −6.990; p < 0.001).
dSignificant differences between patients in the LDG, MDG and HDG for allowed take-home methadone days per week (ANOVA; F(2,603) = 6.750; p < 0.001). Post-hoc tests (Duncan Scheffé’s) revealed that patients in the HDG had significantly fewer take-home days than patients in the LDG (p < 0.001) but not in the MDG (p > 0.05).
eSignificant differences between patients in the LDG, MDG and HDG for length of stay in MMT (ANOVA; F(2,611) = 7.734; p < 0.001). Post-hoc tests (Duncan Scheffé’s) revealed that patients in the HDG had a significantly longer length of stay in MMT than patients in the LDG (p < 0.001) but not in the MDG (p > 0.05).
fSignificant differences between patients in the LDG, MDG and HDG for the number of consultations in the past 6 months (ANOVA; F(2,603) = 5.907; p < 0.01). Post-hoc tests (Duncan Scheffé’s) revealed that patients in the HDG had significantly more consultations than patients in the LDG (p < 0.01) or in the MDG (p < 0.05).
gSignificant differences between patients in the LDG, MDG and HDG for alcohol use in the past 30 days (ANOVA; F(2,598) = 5.087; p < 0.01). Post-hoc tests (Duncan Scheffé’s) revealed that patients in the HDG had significantly more alcohol consumption days than patients in the LDG (p < 0.01) but not in the MDG (p > 0.05).
hNo differences between patients in the LDG, MDG and HDG for cannabis use in the past 30 days (ANOVA; F(2,604) = 0.160; p > 0.05).