J Can Chiropr Assoc 2026 (Apr); 70 (1): 27-54

Appendix 4. Study health service outcomes for secondary analysis RCT reports only

Author Surname and Year	Condition	Other health service outcomes for secondary analysis	Findings of secondary analysis
Leininger 2016 Secondary Analysis of Maiers 2014	Neck pain	Total costs for SMT+HEA were 5% lower than HEA (mean difference: –$111; 95%CI −$1,354 to $899) and 47% lower than SRE+HEA (mean difference: –$1,932; 95%CI –$2,796 to –$1,097). SMT+HEA also resulted in a greater reduction of neck pain over the year relative to HEA (0.57; 95%CI 0.23 to 0.92) and SRE+HEA (0.41; 95%CI 0.05 to 0.76) SMT+HEA yielded greater reductions of neck disability and QALY gains compared to HEA (disability = 1.67 95%CI: −0.15; 3.41; QALYs = 0.009 95%CI: −0.011; 0.029) and SRE+HEA (disability=1.85; 95%CI: 0.06; 3.57; QALYs=0.009 95%CI: −0.009; 0.027)	On average, SMT+HEA resulted in better clinical outcomes and lower total societal costs relative to SRE+HEA and HEA alone, with a 0.75 to 0.81 probability of cost-effectiveness for willingness to pay thresholds of $50,000 to $200,000 per QALY. If adopting a healthcare perspective, costs for SMT+HEA were 66% higher than HEA (mean difference: $515; 95%CI $225 to $1,094), resulting in an ICER of $55,975 per QALY gained.
Maiers 2021 Secondary Analysis of Maiers 2019	Back pain and disability	Back pain duration was significantly and inversely associated with 12-week back disability recovery in older adults with back pain duration of 14.5 to 30 years OR = 0.321 [95%CI: 0.13, 0.740] (p=0.008), and >30 years OR 0.333 [95%CI: 0.127, 0.874] (p=0.026)	Among older adults with back disability, a longer duration of symptoms greater than 14.5 years predicts a poorer response to SMT and exercise

Abbreviations:

CI, Confidence Intervals;
HEA, Home Exercise and Advice;
OR, Odds Ratio;
QALY, Quality-Adjusted Life Year;
SRE, Supervised Rehabilitative Exercise;
SMT, Spinal Manipulative Therapy.