Table 1. Characteristics of the 8 Cohort Studies included in the Final Analysis of Opioids and Fracture Risk.

Author, year; location	Age of the participants, years	Fracture type/assessment	Study design	Cohort size	Follow-up time	Models	Adjustment for covariates	NOS
Guo, 1998, Swedish	≥75	Hip/ICD-9	Prospective cohort	1608	4.4 years	Cox proportional hazards models	Age, gender, education, residence, ADL limitation, cognitive impairment, history of stroke and tumors	8
Kristine, 2003; USA	≥65	Fractures/radiology reports	Prospective cohort	8127	4.8 years	Cox proportional hazards models	Age, gender, race, health status, smoking, walking exercise, functional impairment, cognitive function, depression, weight change	9
Card et al., 2004; UK	NA	Hip/NA	Prospective cohort	99467	7.3 per 10000 person-years	Cox regression models	Age, gender, corticosteroid use	6
Sachin, 2006; USA	≥65	Hip/ICD-9	Prospective cohort	362503	464 days	Cox regression models	Age, gender, antidepressant use, antipsychotic use, anxiolytic /hypnotic use	7
Kathleen, 2010; USA	≥60	Fractures/ICD-9	Prospective cohort	2341	32.7 months	Cox proportional hazards models	Age, gender, smoking, depression, substance abuse, dementia, comorbidities, prior fracture, pain site, antidepressant use, sedative use, HRT /bisphosphonate use	9
Miller, 2011; USA	≥65	Fractures/ICD-9	Retrospective cohort	17310	451 per 1000 person years	Cox proportional hazards models	Age, gender, diabetes stroke, osteoarthritis, comorbidity index, stroke, diabetes	6
Vestergaard 2012; Denmark	45–58	Fractures/X-ray	Prospective cohort	2016	10 years	Cox proportional hazards models	Age, HT, BMI, baseline spine BMD, family or prior fracture, serum 25-hydroxy-vitamin D and smoking	9
Laura, 2013; USA	58.73±13.43	Lower extremity/ICD-9	Retrospective cohort	7447	3–8 years	Cox proportional hazards models	Age, race, completeness of SCI level and duration of SCI	7

Note: fractures indicate overall fractures; hip indicates hip fracture; NOS: Newcastle-Ottawa Scale