Table 5

Cost-effectiveness results

Mean
Costs (SD)*
Δ Costs
(95% CI)
Mean
Outcome (SD)*
Δ Outcomes
(95% CI)
ICER
(95% CI)
Societal Perspective
Pain Reduction

SMT + HEA$2,198 ($2,040)-2.4 (2.1)-Reference
HEA$2,305 ($1,634)-1.6 (1.9)-Dominated
SRE + HEA$4,129 ($1,438)-1.8 (1.9)-Dominated

Disability Reduction

SMT + HEA$2,198 ($2,040)-7.4 (9.9)-Reference
HEA$2,305 ($1,634)-6.1 (8.8)-Dominated
SRE + HEA$4,129 ($1,438)-5.6 (8.5)-Dominated

QALYs Gained (SF-6D)

SMT + HEA$2,198 ($2,040)-0.039 (0.106)-Reference
HEA$2,305 ($1,634)-0.031 (0.101)-Dominated
SRE + HEA$4,129 ($1,438)-0.030 (0.084)-Dominated

Sensitivity Analyses
QALYs Gained (EQ-5D)

SMT + HEA$2,198 ($2,040)-0.027 (0.110)-Reference
HEA$2,305 ($1,634)-0.020 (0.090)-Dominated
SRE + HEA$4,129 ($1,438)-0.011 (0.090)-Dominated

Healthcare Perspective
Pain Reduction

HEA$779 ($281)-1.6 (1.9)-Reference
SMT + HEA$1,297 ($1,792)$515 ($225 to $1,094)2.4 (2.1)0.57 (0.23 to 0.92)$895 ($317 to $3,178) ¥
SRE + HEA$2,556 ($505)-1.8 (1.9)-Dominated

Disability Reduction

HEA$779 ($281)-6.1 (8.8)-Reference
SMT + HEA$1,297 ($1,792)$515 ($225 to $1,094)7.4 (9.9)1.67 (-0.15 to 3.41)$308 ($97 to Dominated) ¥
SRE + HEA$2,556 ($505)-5.6 (8.5)-Dominated

QALYs Gained (SF6D)

HEA$779 ($281)-0.031 (0.101)-Reference
SMT + HEA$1,297 ($1,792)$515 ($225 to $1,094)0.039 (0.106)0.009 (-0.011 to 0.029)$55,975 ($18,733 to Dominated) ¥
SRE + HEA$2,556 ($505)-0.030 (0.084)-Dominated
*Unadjusted mean (SD);
Adjusted mean (95% bias-corrected bootstrap confidence intervals) from longitudinal model for treatments with higher costs and better outcomes;
Dominated = worse mean outcome and higher mean cost;
¥ICERs are calculated based on 7 digit accuracy of Δ in costs and outcomes, reported Δ in costs and outcomes were rounded for presentation;

HEA = Home exercise and advice;
ICER = Incremental cost-effectiveness ratio;
SMT = Spinal manipulation therapy;
SRE = Supervised rehabilitative exercise;
QALY = Quality-adjusted life year