Logo of nihpaAbout Author manuscriptsSubmit a manuscriptHHS Public Access; Author Manuscript; Accepted for publication in peer reviewed journal;
PMC full text:
Spine (Phila Pa 1976). Author manuscript; available in PMC 2013 Sep 1.
Published in final edited form as:
Spine (Phila Pa 1976). 2012 Sep 1; 37(19): 1693–1701.
doi:  10.1097/BRS.0b013e3182541f45

Table 2

Linear Regression Models to Predict Annual Expenditures (2008$)a on Ambulatory Visits to US Medical Physicians, Chiropractors, and Physical Therapists for Spine Conditions

Medical CareChiropractic CarePhysical Therapy
Coefficient (95% CI)P-
value
Coefficient (95% CI)P-
value
Coefficient (95% CI) 1,358P-
value
No. of MEPS Respondents in Sample7,6474,5071,358
Yearb1.04 (1.02, 1.05)<0.0011.02 (1.00, 1.04)0.060.99 (0.96, 1.01)0.31
Age1.00 (1.00, 1.00)0.451.00 (1.00, 1.00)0.721.01 (1.00, 1.01)0.00
Gender
 male1.00 (Reference)1.00 (Reference)1.00 (Reference)
 female0.99 (0.92, 1.06)0.701.16 (1.07, 1.27)0.001.22 (1.05, 1.41)0.01
US Region
 Northeast1.00 (Reference)1.00 (Reference)1.00 (Reference)
 Midwest0.90 (0.80, 1.02)0.090.89 (0.78, 1.03)0.110.94 (0.75, 1.18)0.61
 South0.87 (0.78, 0.97)0.011.02, 0.89, 1.17)0.810.93 (0.75, 1.15)0.51
 West0.91 (0.80, 1.03)0.150.90 (0.79, 1.03)0.130.82 (0.65, 1.02)0.08
Rurality
 Non-MSA1.00 (Reference)1.00 (Reference)1.00 (Reference)
 MSA1.03 (0.94, 1.13)0.461.44 (1.28, 1.61)<0.0011.03 (0.85, 1.24)0.79
Race/Ethnicity
 Hispanic1.01 (0.88, 1.16)0.890.98 (0.78, 1.23)0.870.73 (0.55, 0.98)0.04
 Non-Hispanic White1.00 (Reference)1.00 (Reference)1.00 (Reference)
 Non-Hispanic Black or African American0.96 (0.85, 1.08)0.461.18 (0.94, 1.47)0.151.02 (0.78, 1.34)0.87
 Other or multiple races0.89 (0.74, 1.08)0.241.25 (0.99, 1.59)0.061.23 (0.86, 1.75)0.27
Marital status
 married1.00 (Reference)1.00 (Reference)1.00 (Reference)
 divorced, separated, or widowed0.95 (0.87, 1.04)0.301.03 (0.92, 1.16)0.570.97 (0.81, 1.15)0.71
 never married0.94 (0.83, 1.07)0.361.02 (0.89, 1.17)0.781.07 (0.84, 1.35)0.59
Employment status
 employed1.00 (Reference)1.00 (Reference)1.00 (Reference)
 ever unemployed (or retired) during year1.03 (0.94, 1.13)0.561.00 (0.90, 1.09)0.920.92 (0.77, 1.11)0.38
Education
 high school graduate or less1.00 (Reference)1.00 (Reference)1.00 (Reference)
 some college or associate's degree1.05 (0.94, 1.18)0.371.06 (0.94, 1.19)0.330.88 (0.71, 1.10)0.27
 bachelor’s or graduate degree1.11 (1.01, 1.23)0.041.04 (0.93, 1.17)0.490.99 (0.82, 1.19)0.91
Health Insurance Coverage
 private1.36 (1.18, 1.57)<0.0011.21 (1.03, 1.43)0.201.02 (0.66,1.57)0.95
 public1.06 (0.90, 1.25)0.460.97 (0.79, 1.18)0.740.66 (0.41, 1.05)0.08
 uninsured1.00 (Reference)1.00 (Reference)1.00 (Reference)
Any Limitation
 No1.00 (Reference)1.00 (Reference)1.00 (Reference)
 Yes1.52 (1.40, 1.65)<0.0011.21 (1.10, 1.34)<0.0011.23 (1.06, 1.42)0.07
Self-reported Health Status
 Excellent, Very Good, or Good1.00 (Reference)1.00 (Reference)1.00 (Reference)
 Fair or Poor1.36 (1.23, 1.50)<0.0011.06 (0.94, 1.20)0.341.12 (0.92, 1.36)0.25
Abbreviations: MEPS, Medical Expenditure Panel Survey; CI, Confidence Interval

aLinear regression models predict annual expenditures in hundreds (2008$, log transformed)
bTest of trend (Year included in models as a categorical variable)