Table 1. Characteristics of the Included Studies in the Meta-Analysis.
| Authors and year of publication | Country | Study design | Number of participants | Mean age (years) | Maximum follow-up year | Adjusted confounders | Methods used for controlling confounders | Quality score |
|---|---|---|---|---|---|---|---|---|
| Khatod et al., 2015 [19] | United States | Cohort | Users 2292 Nonusers 10 586 | 66.7 | 9.7 | Age, sex, body mass index, American Society of Anesthesiologists score, race, diabetic status, type of implant fixation, surgeon, hospital annual mean volume, surgeon arthroplasty fellowship training (Limited adjustment) | Cox proportional hazards models | 7 |
| Prieto-Alhambra et al., 2014 [16] | Denmark | Cohort | Users 1558 Nonusers 8966 | 75.6 | 10 | Age, sex, joint replaced (hip/knee), year of primary hip/knee replacement surgery, marital status, working status, income, number of visits to general practitioners/specialists (in the previous year), a history of fracture (other than hip fracture), osteoarthritis, comorbidity, use of medications other than bisphosphonates, use of calcium and vitamin D supplements, Charlson comorbidity index (Good adjustment) | Propensity score matching, Cox proportional hazards models | 8 |
| Prieto-Alhambra et al., 2011 [17] | Unite Kingdom | Cohort | Users 1912 Nonusers 40 083 | 69.98 | 15 | Age, sex, body mass index, type of joint replaced (hip/knee), year of joint replacement operation, recorded diagnosis of osteoarthritis, previous fracture before surgery, use of calcium and vitamin D supplements, use of medications other than bisphosphonates, smoking status, alcohol intake, general practice deprivation score, location of surgery, comorbid conditions (Good adjustment) | Propensity score-adjusted regression | 8 |
| Thillemann et al., 2010 [18] | Denmark | Case-control | Cases 632 Controls 1264 | >10 | N/A | Age, sex, marital status, education, income, location of surgery, year of primary total hip arthroplasty, medication other than bisphosphonates, comorbid chronic disease, Charlson comorbidity index, fixation technique (Good adjustment) | Incidence-density matching, conditional logistic regression | 8 |
N/A: not applicable