Table 4.
Comparison of neuropsychiatric inventory-nursing home version (NPI-NH) total score between control and intervention (stepwise protocol for treatment of pain) groups using repeated measures analysis of covariance (ANCOVA)*
| Week | Mean (SD) NPI-NH total | Effect of intervention on NPI-NH total† | Intracluster correlation coefficient‡ | ||
|---|---|---|---|---|---|
| Control group | Intervention group | Estimate (95% CI) | P value | ||
| 0 | 31.4 (21.4), n=177 | 34.8 (21.9), n=175 | — | — | 0.106 |
| 2 | 26.1 (19.2), n=161 | 26.5 (20.3), n=158 | −2.9 (0.03 to −5.9) | 0.052 | 0.129 |
| 4 | 26.0 (20.1), n=160 | 23.4 (20.0), n=148 | −5.7 (−2.3 to −9.1) | 0.001 | 0.116 |
| 8 | 26.9 (20.7), n=157 | 21.0 (19.3), n=147 | −9.0 (−5.5 to −12.6) | <0.001 | 0.157 |
| 12 | 28.0 (21.1), n=152 | 23.0 (20.0), n=142 | −8.4 (−4.7 to −12.2) | <0.001 | 0.210 |
*Baseline score as covariate and least squares weighted by number of patients within cluster; P values from multivariate test of intervention and cross effect between week and intervention were both <0.001.
†Variable estimate by week of effect of intervention on NPI-NH from estimated model.
‡Proportion of total variance between clusters, and measured within framework of ANCOVA.