Table 3.

Hierarchical linear model results predicting chiropractic visit frequency for patients with chronic spinal pain

	Chronic Low Back Pain (n = 852)	p-values for coefficients in block	Chronic Neck Pain (n = 705)	p-values for coefficients in block
Enabling factors - p-values for block1	0.032		0.986
Some insurance coverage for chiropractic – Reference = No coverage	0.44	.008	0.14	.408
Unknown insurance coverage	0.06	.845	−0.15	.689
Need factors – pain characteristics - p-values for block1	<.001		<.001
Rating of pain past 7 days (0–10), mean (SD)	0.06	.238	0.00	.972
Oswestry or Neck Disability Index score (0–100), mean (SD)	0.02	.024	0.03	<.001
Have both CLBP and CNP	0.09	.508	0.15	.309
Years of pain - Reference = < 1 year
1 year to less than 2 years	0.38	.231	0.36	.307
2 years to less than 5 years	−0.26	.338	− 0.07	.787
5 years to less than 10 years	− 0.29	.259	− 0.11	.674
10+ years	−0.39	.088	−0.03	.894
Unknown	−0.10	.839	−0.01	.986
Need factors – lifestyle and point in care - p-values for block1	<.001		<.001
Heavy labor - Reference = No heavy labor
Non-workday heavy labor: > 0% but < 20%	0.41	.055	−0.28	.244
Workday heavy labor: > 0% but < 20%	0.47	.010	−0.06	.732
Non-workday heavy labor: > 20%	0.23	.533	−0.02	.971
Workday heavy labor: > 20%	0.22	.350	0.19	.458
Heavy labor: missing	0.43	.104	0.30	.282
New patient (< 30 days)	0.63	.006	0.69	.005
Unknown time with this chiropractor	0.32	.082	0.45	.019
Ended care during study period	−1.21	<.001	−1.57	<.001
Perceived need factors – goals for treatment - p-values for block1	0.636		0.237
Perceived need factors – pain beliefs - p-values for block1	0.063		0.766
Perceived need factors – other psychological factors - p-values for block1	0.295		0.100
Predisposing factors - p-values for block1	0.048		0.171
Age in years	0.01	.104	0.01	.111
Female	−0.37	.013	−0.12	.525
Education: At least a 4-year degree	0.04	.805	−0.15	.307
Chiropractor practice characteristics - p-values for block1	<.001		<.001
Average number of patients treated per day	0.03	<.001	0.04	<.001
Percentage of patients on preventive/maintenance	0.01	.259	0.01	.020
Years in practice - Reference = 5 to 10 years
In practice > 10 to 20 years	−0.50	.072	−0.16	.567
In practice > 20 to 30 years	−0.72	.014	−1.01	.001
In practice > 30 years	0.24	.487	−0.13	.704
Clinic location is urban (> 50,000 population)	−0.20	.318	−0.18	.387
Average number of physical modalities used	−0.12	.067	−0.04	.624
College from which chiropractor graduated - p-value for block1	0.130		0.060
State/Region - p-value for block1	0.014		0.072
State/Region - Reference = California
Florida	−0.67	.096	−0.66	.109
Minnesota	−0.57	.625	−1.31	.205
New York	−1.49	.001	−1.20	.010
Oregon	0.48	.558	0.20	.802
Texas	−0.30	.574	−0.05	.927

¹P-value for the likelihood-ratio test of the incremental explanatory power of each block of variables added to a model containing all previous blocks