Table 1

Included studies, by study design and first author

References	Title	Year	Rating*
	Prospective cohort studies
Carey [23]	The outcomes and costs of care for acute low back pain among patients seen by primary care practitioners, chiropractors, and orthopedic surgeons	1995	A
Elder [24]	Comparative effectiveness of usual care with or without chiropractic care in patients with recurrent musculoskeletal back and neck Pain	2018	A
Graves [25]	Factors associated with early magnetic resonance imaging utilization for acute occupational low back pain: a population-based study from Washington State workers' compensation	2012	A
Keeney [26]	Early predictors of lumbar spine surgery after occupational back injury: results from a prospective study of workers in Washington State	2013	A
	Cohort studies (retrospective/cross-sectional)
Anderson [27]	Three patterns of spinal manipulative therapy for back pain and their association with imaging, injection procedures, and surgery: a cohort study of insurance claims	2021	A
Anderson [28]	Risk of treatment escalation in recipients vs nonrecipients of spinal manipulation for musculoskeletal cervical spine disorders: analysis of insurance claims	2021	H
Bezdjian [29]	Efficiency of primary spine care as compared to conventional primary care: a retrospective observational study at an Academic Medical Center	2022	H
Davis [30]	The effect of reduced access to chiropractic care on medical service use for spine conditions among older adults	2021	H
Davis [31]	Access to chiropractic care and the cost of spine conditions among older adults	2019	H
Fritz [32]	Importance of the type of provider seen to begin health care for a new episode low back pain: associations with future utilization costs	2016	H
Hong [33]	Clinician-level predictors for ordering low-value imaging	2017	H
Hurwitz [34]	Variations in patterns of utilization and charges for neck pain in North Carolina, 2000 to 2009: a statewide claims' data analysis	2016	H
Hurwitz [35]	Variations in patterns of utilization and charges for the care of low back pain in North Carolina, 2000 to 2009: a statewide claims' data analysis	2016	H
Jin [36]	Healthcare resource utilization in management of opioid-naive patients with newly diagnosed neck pain	2022	H
Kazis [37]	Observational retrospective study of the association of initial healthcare provider for new-onset low back pain with early and long-term opioid use	2019	H
Liliedahl [38]	Cost of care for common back pain conditions initiated with chiropractic doctor vs medical doctor/doctor of osteopathy as first physician: experience of one Tennessee-based general health insurer	2010	H
Louis [39]	Association of initial provider type on opioid fills for individuals with neck pain	2020	H
Rhon [12]	The influence of a guideline-concordant stepped care approach on downstream healthcare utilization in pts with spine and shoulder pain	2019	H
Weeks [40]	Cross-sectional analysis of per capita supply of doctors of chiropractic and opioid use in younger Medicare beneficiaries	2016	H
Weeks [41]	The association between use of chiropractic care and costs of care among older Medicare patients with chronic low back pain and multiple comorbidities	2016	H
Whedon [9]	Initial choice of spinal manipulation reduces escalation of care for chronic low back pain among older Medicare beneficiaries	2022	H
Whedon [42]	Long-Term Medicare Costs Associated With Opioid Analgesic Therapy vs Spinal Manipulative Therapy for Chronic Low Back Pain in a Cohort of Older Adults	2021	H
Whedon [43]	Initial choice of spinal manipulative therapy for treatment of chronic low back pain leads to reduced long-term risk of adverse drug events among older Medicare beneficiaries	2021	H
Whedon [44]	Association between utilization of chiropractic services for treatment of low back pain and use of prescription opioids	2018	H
Whedon [45]	Impact of chiropractic care on use of prescription opioids in patients with spinal pain	2020	H
Whedon [40]	Association between chiropractic care and use of prescription opioids among older Medicare beneficiaries with spinal pain: a retrospective observational study	2022	H
	Cost studies
Grieves [47]	Cost minimization analysis of low back pain claims data for chiropractic vs medicine in a managed care organization	2009	A
Haas [48]	Cost-effectiveness of medical and chiropractic care for acute and chronic low back pain	2005	H
Harwood [5]	Where to start? A two-stage residual inclusion approach to estimating influence of the initial provider on healthcare utilization and costs for low back pain in the US	2022	H
Jarvis [49]	Cost per case comparison of back injury claims of chiropractic versus medical management for conditions with identical diagnostic codes	1991	A
Kominski [50]	Economic evaluation of four treatments for low-back pain: results from a randomized controlled trial	2005	A
Legorreta [51]	Comparative analysis of individuals with and without chiropractic coverage: patient characteristics, utilization, and costs	2004	H
Leininger [52]	Cost-effectiveness of spinal manipulative therapy, supervised exercise, and home exercise for older adults with chronic neck pain	2016	H
Mosley [53]	Cost effectiveness of chiropractic care in a managed care setting	1996	A
Nelson [54]	Effects of a managed chiropractic benefit on the use of specific diagnostic and therapeutic procedures in the treatment of low back and neck pain	2005	A
Phelan [55]	An evaluation of medical and chiropractic provider utilization and costs: treating injured workers in North Carolina	2004	A
Shekelle [56]	Comparing the costs between provider types of episodes of back pain care	1995	A
Smith [57]	Costs and recurrences of chiropractic and medical episodes of low-back care	1997	H
Stano [58]	A comparison of healthcare costs for chiropractic and medical patients	1993	A
Stano [59]	The economic role of chiropractic: an episode analysis of relative insurance costs for low back care	1993	A
Stano [60]	Further analysis of healthcare costs for chiropractic and medical patients	1994	A
Stano [61]	Chiropractic and medical care costs of low back care: results from a practice-based observational study	2002	A
Stano [62]	Chiropractic and medical costs of low back care	1996	A
	Randomized controlled trial
Cherkin(63)	A comparison of physical therapy, chiropractic manipulation, and provision of an educational booklet for the treatment of patients with low back pain	1998	A

^*A, acceptable quality, moderate risk of bias;

H, high quality, low risk of bias