Examining Differences in Recovery Outcomes Between Male and Female Hip Fracture Patients: Design and Baseline Results of a Prospective Cohort Study From the Baltimore Hip Studies

Abstract

Background: Incidence of hip fractures in men is expected to increase, yet little is known about consequences of hip fracture in men compared to women. It is important to investigate differences at time of fracture using the newest technologies and methodology regarding metabolic, physiologic, neuromuscular, functional, and clinical outcomes, with attention to design issues for recruiting frail older adults across numerous settings. Objectives: To determine whether at least moderately-sized sex differences exist across several key outcomes after a hip fracture. Design, Setting, & Participants: This prospective cohort study (Baltimore Hip Studies 7th cohort [BHS-7]) was designed to include equal numbers of male and female hip fracture patients to assess sex differences across various outcomes post-hip fracture. Participants were recruited from eight hospitals in the Baltimore metropolitan area within 15 days of admission and were assessed at baseline, 2, 6 and 12 months post-admission. Measurements: Assessments included questionnaire, functional performance evaluation, cognitive testing, measures of body composition, and phlebotomy. Results: Of 1709 hip fracture patients screened from May 2006 through June 2011, 917 (54%) were eligible and 39% (n=362) provided informed consent. The final analytic sample was 339 (168 men and 171 women). At time of fracture, men were sicker (mean Charlson score= 2.4 vs. 1.6; p<0.001) and had worse cognition (3MS score= 82.3 vs. 86.2; p<0.05), and prior to fracture were less likely to be on bisphosphonates (8% vs. 39%; p<0.001) and less physically active (2426 kilocalories/week vs. 3625; p<0.001). Conclusions: This paper provides the study design and methodology for recruiting and assessing hip fracture patients and evidence of baseline and pre-injury sex differences which may affect eventual recovery one year later.

Long‐term sex differences in all‐cause and infection‐specific mortality post hip fracture

“…4 More baseline comorbidity among men compared to women may explain greater allcause mortality in men because comorbid conditions prior to fracture have been consistently demonstrated to predict postfracture mortality. 2,20 Lower cognitive function at hospital admission among men than women could also explain their higher all-cause mortality rate since it has been shown that impaired cognition is associated with allcause mortality at 6-months after hip fracture. 6 However, both comorbidity and cognitive function were adjusted for in the models, so they are not likely to explain men's increased mortality.…”

“…Further details regarding the study design and methodology are available elsewhere. 2 The BHS-7 cohort enrolled 339 participants (168 men and 171 women) and was restricted to an analytic cohort of 300 participants (145 men, 155 women) with complete data on salient variables measured at baseline.…”

Residual Disability, Mortality, and Nursing Home Placement After Hip Fracture Over 2 Decades

“…The Baltimore Hip Studies (BHS) began in 1983 to study outcomes in older adults with hip fractures. The BHS assessed recovery among hip fracture patients within five cohort studies (BHS1 9 , BHS2 6 , BHS3 21 , BHS6 22 , BHS7 23 ) and two randomized controlled trials (BHS4 24 and BHS5 25 ). These studies were approved by the Institutional Review Boards of the University and the individual study hospitals where recruitment took place.…”

Differential misclassification of cognitive impairment by sex among hip fracture patients

“…Patients were excluded if not community-dwelling at the time of fracture, non-English speaking, bedbound for 6 months or more prior to fracture, lived >70 miles from the hospital, weighed >300 pounds, did not have surgical hip repair, or had hardware in the contralateral hip. 13 BHS-7 oversampled males by frequency-matching the enrollment of females to males by hospital and time of admission yielding approximately 50% male sample (male = 168; female = 171). Proxies provided data on the patient's behalf if participants scored <36 on the 3MS.…”

“…Proxies provided data on the patient's behalf if participants scored <36 on the 3MS. 13 Nine participants were excluded due to missing medical record abstraction information (1 male) or a baseline 3MS (4 females, 4 males). Thus, the analytic sample was 330 (163 males, 167 females).…”