Table 3.
Results of hierarchical linear models for each outcome: models adding the impact of frequency of other types of visits and other patient characteristics
| LBP Rating (n=1361) | ODI (n=1362) | NP Rating (n=1214) | NDI (n=1213) | |||||
|---|---|---|---|---|---|---|---|---|
|
|
||||||||
| Adding other visit frequency | Adding all other variables | Adding other visit frequency | Adding all other variables | Adding other visit frequency | Adding all other variables | Adding other visit frequency | Adding all other variables | |
|
| ||||||||
| Intercept | 2.82 (0.1)*** | 0.91 (0.3)** | 14.81 (0.6)*** | 11.80 (2.1)*** | 3.05 (0.1)*** | 0.10 (0.4) | 17.41 (0.7)*** | 4.16 (2.3) |
| Weeks Since BL (Weeks) | −0.02 (0.0)** | −0.02 (0.0)** | −0.25 (0.0)*** | −0.25 (0.0)*** | −0.02 (0.0)* | −0.02 (0.0)* | −0.21 (0.0)*** | −0.21 (0.0)*** |
| Visits to chiropractor (Ref: Monthly to < monthly) | ||||||||
| Biweekly up to monthly | 0.24 (0.1) | 0.19 (0.1) | 0.66 (0.8) | 0.51 (0.6) | 0.25 (0.1) | 0.21 (0.1)* | 0.68 (0.9) | 0.69 (0.7) |
| Weekly up to biweekly | 0.55 (0.1)*** | 0.22 (0.1)* | 4.13 (0.8)*** | 2.32 (0.6)*** | 0.45 (0.1)** | 0.19 (0.1) | 3.83 (0.9)*** | 2.53 (0.7)*** |
| More than weekly | 0.82 (0.2)*** | 0.40 (0.1)** | 6.59 (1.0)*** | 3.95 (0.8)*** | 0.62 (0.2)*** | 0.24 (0.1) | 4.14 (1.1)*** | 2.18 (0.9)* |
| Unknown | 0.74 (0.3)** | 0.51 (0.2)* | 4.33 (1.6)** | 2.06 (1.3) | 0.70 (0.3)* | 0.58 (0.2)* | 3.69 (1.8)* | 3.61 (1.4)* |
| Wks*Biweekly to monthly | 0.00 (0.0) | 0.00 (0.0) | 0.08 (0.0) | 0.08 (0.0) | −0.01 (0.0) | −0.01 (0.0) | −0.06 (0.1) | −0.06 (0.1) |
| Wks*Weekly to biweekly | −0.01 (0.0) | −0.01 (0.0) | 0.04 (0.1) | 0.04 (0.1) | −0.01 (0.0) | −0.01 (0.0) | −0.06 (0.1) | −0.06 (0.1) |
| Wks*More than weekly | −0.05 (0.0)*** | −0.05 (0.0)*** | −0.16 (0.1)* | −0.16 (0.1)* | −0.03 (0.0)* | −0.03 (0.0)* | −0.16 (0.1)* | −0.16 (0.1)* |
| Other CT provider visits | ||||||||
| Monthly to < monthly | 0.37 (0.1)** | 0.22 (0.1)* | 0.61 (0.8) | 0.16 (0.6) | 0.40 (0.1)** | 0.23 (0.1)* | 1.46 (0.8) | 0.55 (0.7) |
| Biweekly up to monthly | 0.42 (0.2)* | 0.19 (0.1) | 2.21 (1.1)* | 1.43 (0.8) | 0.33 (0.2) | 0.10 (0.1) | 0.21 (1.2) | −1.23 (0.9) |
| > Weekly up to biweekly | 0.64 (0.2)*** | 0.33 (0.1)* | 5.66 (1.0)*** | 4.43 (0.8)*** | 0.70 (0.2)*** | 0.45 (0.1)** | 4.31 (1.1)*** | 2.89 (0.9)*** |
| Unknown | 0.00 (0.0) | 0.00 (0.0) | 0.00 (0.0) | 0.00 (0.0) | 0.00 (0.0) | 0.00 (0.0) | 0.00 (0.0) | 0.00 (0.0) |
| Wks* Monthly to <monthly | 0.00 (0.0) | 0.00 (0.0) | 0.04 (0.0) | 0.04 (0.0) | −0.01 (0.0) | −0.01 (0.0) | −0.11 (0.1)* | −0.11 (0.1)* |
| Wks* Biweekly to monthly | −0.01 (0.0) | −0.01 (0.0) | 0.00 (0.1) | 0.00 (0.1) | 0.01 (0.0) | 0.01 (0.0) | 0.13 (0.1) | 0.14 (0.1) |
| Wks*>Weekly to biweekly | 0.01 (0.0) | 0.01 (0.0) | 0.12 (0.1) | 0.12 (0.1) | 0.00 (0.0) | 0.00 (0.0) | 0.11 (0.1) | 0.11 (0.1) |
| Medical provider visit | ||||||||
| Monthly to < monthly | 0.58 (0.1)*** | 0.20 (0.1) | 4.75 (0.8)*** | 1.78 (0.6)** | 0.35 (0.1)* | −0.06 (0.1) | 4.20 (0.9)*** | 1.17 (0.7) |
| Biweekly up to monthly | 1.46 (0.3)*** | 0.78 (0.2)*** | 15.40 (1.7)*** | 8.36 (1.3)*** | 1.41 (0.3)*** | 0.73 (0.3)** | 17.24 (2.0)*** | 10.02 (1.6)*** |
| > Weekly up to biweekly | 1.09 (0.5)* | 0.35 (0.4) | 13.10 (2.9)*** | 5.92 (2.3)** | 0.30 (0.6) | −0.18 (0.5) | 6.79 (3.9) | 0.00 (3.1) |
| Unknown | 0.00 (0.0) | 0.00 (0.0) | 0.00 (0.0) | 0.00 (0.0) | 0.00 (0.0) | 0.00 (0.0) | 0.00 (0.0) | 0.00 (0.0) |
| Wks* Monthly to <monthly | 0.00 (0.0) | 0.00 (0.0) | 0.01 (0.1) | 0.01 (0.1) | 0.00 (0.0) | 0.00 (0.0) | 0.12 (0.1)* | 0.12 (0.1)* |
| Wks* Biweekly to monthly | −0.02 (0.0) | −0.02 (0.0) | 0.17 (0.1) | 0.17 (0.1) | −0.01 (0.0) | −0.01 (0.0) | −0.08 (0.1) | −0.08 (0.1) |
| Wks*>Weekly to biweekly | −0.01 (0.0) | −0.02 (0.0) | 0.07 (0.2) | 0.06 (0.2) | 0.10 (0.1) | 0.10 (0.1) | 0.99 (0.3)*** | 0.99 (0.3)*** |
| Other patient characteristics | See appendix for coefficients | See appendix for coefficients | See appendix for coefficients | See appendix for coefficients | ||||
|
| ||||||||
| Partitioned Variance | ||||||||
| Clinic (Intercept) | 0.02 (0.0) | 0.01 (0.0) | 5.48 (2.1) | 1.84 (1.1) | 0.07 (0.0) | 0.00 (0.0) | 3.80 (2.3) | 0.57 (1.3) |
| ID (Weeks) | 0.01 (0.0) | 0.01 (0.0) | 0.21 (0.0) | 0.21 (0.0) | 0.01 (0.0) | 0.01 (0.0) | 0.23 (0.0) | 0.24 (0.0) |
| ID (Intercept) | 2.23 (0.1) | 1.02 (0.1) | 99.93 (4.6) | 52.38 (2.7) | 2.64 (0.1) | 1.13 (0.1) | 111.07 (5.5) | 58.86 (3.4) |
| Residual | 1.61 (0.0) | 1.61 (0.0) | 27.76 (0.5) | 27.73 (0.5) | 1.60 (0.0) | 1.60 (0.0) | 32.65 (0.7) | 32.62 (0.7) |
|
| ||||||||
| D (df) for main effects | 45.9 (8) *** | 300.7 (33) *** | 92.1 (8) *** | 402.0 (33) *** | 25.6 (8) *** | 288.4 (33) *** | 64.5 (8) *** | 355.9 (33) *** |
| D (df) for interactions | 0.8 (6) | −61.5 (32) | 3.6 (6) | −25.4 (32) | 2.5 (6) | −54.4 (32) | 15.3 (6) *** | −12.2 (32) |
BL = Baseline; CT = complementary therapy providers—here, most often massage therapists; D = Deviance statistic with its degrees of freedom (number of parameters added over previous model), distributed χ2; LBP = low back pain, 0–10 scale; NDI = Neck Disability Index, 0–100 scale; NP = neck pain, 0–10 scale; ODI = Oswestry Disability Index, 0–100 scale; OTC = Over-the-counter medications; Rx = Prescription medications
*
The estimated coefficient or deviance statistic is statistically significant at p<.05.
**
The estimated coefficient or deviance statistic is statistically significant at p<.01.
***
The estimated coefficient or deviance statistic is statistically significant at p<.001.