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

Sex differences and predictors of anti-osteoporosis medication use in the 12 months after hip fracture surgery in adults 65 or older

PURPOSE

This study evaluates sex differences and predictors of anti-osteoporosis medication (AOM) use following a hip fracture, with a focus on older men who exhibit higher mortality rates post-fracture compared to women over the age of 65.

METHODS

Participants included 151 men and 161 women aged 65 and older with hip fractures. The outcome, AOM use, was assessed at baseline (≤ 22 days of hospitalization) and at 2, 6, and 12 months post-hip fracture. Generalized estimating equations (GEE) modeled sex differences and predictors of AOM use during the year post-fracture in 255 participants with complete baseline data and ≥ 1 follow-up observation.

RESULTS

Of the 312 participants, only 53 used AOM at baseline, and 35 initiated use during follow-up. In the unadjusted GEE model, AOM use was significantly less likely in men (OR = 0.42; 95% CI, 0.22-0.78) compared to women. For both men and women, baseline use of AOM was a significant predictor (OR = 28.3; 95% CI, 5.4-148.0 vs. 41.6; 95% CI, 14.0-123.0). The other significant predictors by sex were osteoporosis diagnosis (OR = 3.19; 95% CI, 1.16-8.77) and minimal alcohol use (OR = 3.26; 95% CI, 1.34-7.94) for women versus age (OR = 1.09; 95% CI, 1.01-1.18) for men.

CONCLUSION

In older adults with hip fractures, AOM use is low over the year post-fracture and men are less likely to report AOM use compared to women which has implications for important sex differences in predictors of use. Further research is needed to address overall disparities and sex differences in AOM use.

Hip Fracture Patterns, Hospital Course, and Mortality Differ Between Males and Females

Introduction

The purpose of this study was to describe how hip fractures differentially affect male and female patients regarding fracture pattern, hospital course, and postoperative course.

Materials and Methods

This retrospective case series was performed in a metropolitan healthcare system involving 2996 hip fracture patients >59 years old who underwent surgical management (eg, intramedullary nail, hemiarthroplasty, percutaneous pinning, etc.). Male patients were matched to female patients using 1:2 nearest neighbor matching on the basis of age and Charlson Comorbidity Index. Outcomes of interest included AO/OTA fracture classification, 30- and 90-day readmission, and 30-day and 1-year mortality rates.

Results

The cohort was predominantly female (64.5%). Female patients were more likely to sustain a type 31A fracture compared to males (P = .016). The average CCI was higher for males vs females (3.0 ± 2.5 vs 2.6 ± 2.3, P < .001). Males were more likely to be readmitted at 30 (P < .001) and 90 (P = .015) days after discharge. The 30-day mortality was higher for males vs females (6.6% vs 4.5%, P = .015). Approximately 19.9% of male patients vs 15.1% of females died within a year of surgery (P < .001). The average time to surgery was longer for males vs females (23.8 ± 18.8 vs 22.5 ± 21.9 h, P = .048). Males were more likely to die within a year if they underwent surgery >24 h after admission (P = .029).

Discussion

Hip fractures have different implications for male and female patients. With age, the incidence of IT fractures increased in females, while it decreased in males. On average, males with hip fractures are sicker than females, which likely contributes to the longer time to surgery as well as increased readmission and mortality rates seen in males.

Conclusions

Male and female hip fracture patients are not similar in baseline health status, fracture pattern, or postoperative morbidity and mortality. Orthogeriatricians and other providers that care for this patient population should be aware of these differences when implementing treatment strategies to optimize the recovery of their patients, and while educating patients and their families about postoperative expectations.

Sustained IL-6 and sTNF-αR1 levels after hip fracture predict 5-year mortality: A prospective cohort study from the Baltimore Hip Studies

BACKGROUND

Persistent inflammation is associated with adverse health outcomes, but its impact on mortality has not been investigated previously among hip fracture patients. This article aims to investigate the influence of changes in levels of cytokines in the 2 months after a hip fracture repair on 5-year mortality.

METHODS

This is a prospective cohort study from the Baltimore Hip Studies (BHS) with 191 community-dwelling older men and women (≥65 years) who had recently undergone surgical repair of an acute hip fracture, with recruitment from May 2006 to June 2011. Plasma interleukin-6 (IL-6), soluble tumor necrosis factor alpha receptor1 (sTNFα-R1), and interleukin-1 receptor agonist (IL-1RA) were obtained within 22 days of admission and at 2 months. All-cause mortality over 5 years was determined. Logistic regression analysis tested the associations between the cytokines' trajectories and mortality over 5 years, adjusted for covariates (age, sex, education, body mass index, lower extremity physical activities of daily living, and Charlson comorbidity index).

RESULTS

High levels of IL-6 and sTNFα-R1 at baseline with small or no decline at 2 months were associated with higher odds of 5-year mortality compared with those with lower levels at baseline and greater decline at 2 months after adjustment for age, and other potential confounders (OR = 4.71, p = 0.01 for IL-6; OR = 15.03, p = 0.002 for sTNFα-R1). Similar results that failed to reach significance were found for IL-1RA (OR = 2.40, p = 0.18). Those with higher levels of cytokines at baseline with greater decline did not have significantly greater mortality than the reference group, those with lower levels at baseline and greater decline.

CONCLUSION

Persistent elevation of plasma IL-6 and sTNFα-R1 levels within the first 2 months after hospital admission in patients with hip fracture is associated with higher 5-year mortality. These patients may benefit from enhanced care and earlier intensive interventions to reduce the risk of death.

Longitudinal characteristics of physical frailty and its components in men and women post hip fracture

BACKGROUND

Frailty is an important geriatric syndrome predicting adverse health outcomes in older adults. However, the longitudinal characteristics of frailty components in post-hip fracture patients are less understood. Adopting the Fried frailty definition, we examined the longitudinal trends and sex trajectory differences in frailty and its components over 1 year post-fracture.

METHODS

Three hundred and twenty-seven hip fracture patients (162 men and 165 women with mean age 80.1 and 81.5) from Baltimore Hip Studies 7th cohort with measurements at 22 days after admission, and months 2, 6, and 12 post-fracture were analyzed. Frailty components included: grip strength, gait speed, weight, total energy expenditure, and exhaustion. Longitudinal analysis used mixed effect models.

RESULTS

At baseline, men were sicker with worse cognitive status, and had higher weight and grip strength, but lower total energy expenditure than women (p < 0.001). The prevalence of frailty was 31.5%, 30.2%, and 28.2% at months 2, 6, and 12 respectively, showing no longitudinal trends or sex differences. However, its components showed substantial recovery trends over the post-fracture year after confounding adjustments, including increasing gait speed, reducing risk of exhaustion, and stabilized weight loss and energy expenditure over time. Particularly, while men's grip strength tended to remain stable over first year post surgery within patients, women's grip strength reduced significantly over time within patients. On average over time within patients, women were more active with higher energy expenditures but lower grip strength and weight than men.

CONCLUSION

Significant recovery trends and sex differences were observed in frailty components during first year post-fracture. Overall frailty status did not show those trends over months 2-12 since a summary measure might obscure changes in components. Therefore, frailty components provided important multi-dimensional information on the complex recovery process of patients, indicating targets for intervention beyond the global binary measure of frailty.

Associations of sex, Alzheimer's disease and related dementias, and days alive and at home among older Medicare beneficiaries recovering from hip fracture

BACKGROUND

Males constitute 25% of older adults who experience hip fractures in the United States; a concerning upward trend given poorer health and outcomes among male survivors. Male sex is associated with worse cognitive performance after hip fracture, impacting participation in rehabilitation and long-term outcomes especially for those with Alzheimer's disease or related dementias (ADRD). However, little research has evaluated whether sex differences in post-fracture recovery are greater among those living with ADRD.

METHODS

Data were drawn from 2010 to 2017 Medicare fee-for-service beneficiaries aged 65 years and older who survived hospitalization for hip fracture (n = 69,581). The primary outcome was days alive and at home (DAAH), a validated patient-centered claims-based outcome calculated as 365 days from fracture minus days in hospital, nursing home, rehabilitation facility, emergency department, or time after death. Multivariable Poisson regressions with an interaction term between sex and ADRD status were to model the association between DAAH and ADRD in the 12 months post hip fracture, adjusting for demographics, injury severity, chronic disease burden, and hospital-level fixed effects.

RESULTS

Compared to females, males were younger and had more comorbidities at the time of fracture. Among survivors, males with ADRD spent a mean of 160.7 DAAH compared to 228.4 for males without ADRD, 177.8 for females with ADRD, and 248.0 for females without ADRD. In adjusted analyses, males without ADRD spent 8.2% fewer DAAH compared to females (rate ratio [RR] = 0.92, 95% CI 0.92-0.92). This relative sex difference increased significantly when comparing those living with ADRD, with males spending an additional 3.3% fewer DAAH (interaction RR = 0.96, 95% CI 0.96-0.97).

CONCLUSIONS

Males spend fewer DAAH after hip fracture than females, and this difference increases modestly for males living with ADRD compared to females. This suggests that cognitive impairment may be a small but significant contributor to sex-based differences observed during hip fracture recovery.

Associations between living alone, social interactions, and physical performance differ by sex: Results from the Baltimore Hip Studies

BACKGROUND

There is mixed evidence on whether living arrangements and social interactions are associated with poorer health outcomes after hip fracture repair. Distinct social profiles among male and female older adults may explain some of the differences. However, prior studies did not evaluate these differences by sex. This article aims to assess if the associations between living alone, social interaction, and physical performance differ by sex among hip fracture survivors.

METHODS

This prospective cohort study is part of the Baltimore Hip Studies seventh cohort, with 168 male and 171 female hip fracture patients assessed at baseline (≤22 days after hospitalization) and at 2, 6, and 12 months post admission. Living arrangements and interaction with children or siblings and others in the past 2 weeks were collected at all visits. Physical performance was measured in the follow-up visits with the Short Physical Performance Battery (SPPB). Linear mixed models tested associations of living alone and social interaction with SPPB over time adjusted for age, education, comorbidities, physical functioning pre-fracture, cognitive function, self-rated health, and time.

RESULTS

For men only, living alone was associated with worse performance (0.7 points lower SPPB scores, p = 0.05). Higher social interaction was associated with 0.8 and 1.2 point higher SPPB scores for men and women, respectively (p < 0.05). Visiting with friends was significantly associated with better function among males, while visiting with children or siblings was associated with worse SPPB among females.

CONCLUSIONS

Living arrangements and types of social interaction are differentially associated with physical function for older men and women. Screening for social isolation/integration and including interventions that promote social interaction and participation should be considered in healthcare programs for hip fracture survivors.

Predictors of mobility status one year post hip fracture among community-dwelling older adults prior to fracture: A prospective cohort study

BACKGROUND

Orthopedists and other clinicians assess recovery potential of hip fracture patients at 2 months post-fracture for care planning. It is unclear if examining physical performance (e.g., balance, gait speed, chair stand) during this follow-up visit can identify individuals at a risk of poor functional recovery, especially mobility, beyond available information from medical records and self-report.

METHODS

Data came from 162 patients with hip fracture enrolled in the Baltimore Hip Studies-7th cohort. Predictors of mobility status (ability to walk 1 block at 12 months post-fracture) were the Short Physical Performance Battery (SPPB) comprising balance, walking and chair rise tasks at 2 months; baseline medical chart information (sex, age, American Society of Anesthesiologist physical status rating, type of fracture and surgery, and comorbidities); and self-reported information about the physical function (ability to walk 10 feet and 1 block at pre-fracture and at 2 months post-fracture). Prediction models of 12-month mobility status were built using two methods: (1) logistic regression with least absolute shrinkage and selection operator (LASSO) regularization, and (2) classification and regression trees (CART). Area under ROC curves (AUROC) assessed discrimination.

RESULTS

The participants had a median age of 82 years, and 49.3% (n = 80) were men. Two-month SPPB and gait speed were selected as predictors of 12-month mobility by both methods. Compared with an analytic model with medical chart and self-reported information, the model that additionally included physical performance measures had significantly better discrimination for 12-month mobility (AUROC 0.82 vs. 0.88, p = 0.004).

CONCLUSION

Assessing SPPB and gait speed at 2 months after a hip fracture in addition to information from medical records and self-report significantly improves prediction of 12-month mobility. This finding has important implications in providing tailored clinical care to patients at a greater risk of being functionally dependent who would not otherwise be identified using regularly measured clinical markers.

Predictors of mortality for patients with hip fracture: a study of the nationwide 1-year records of 24,950 fractures in Romania

We conducted a study evaluating incidence rates and influencing factors in Romanian hip fracture patients. Our results showed that the type of fracture and its respective surgical procedure as well as hospital characteristics correlate with mortality. Updated incidences can result in updated treatment guidelines.

PURPOSE

The aim of our study was to assess incidence rates for a revision-calibration of the Romanian FRAX tool and to evaluate particularities of hip fracture cases to determine patient- and hospital-related variables affecting mortality.

METHODS

We conducted a retrospective study using hospital reports of hip fracture codes to the National School of Statistics (NSS) from January 1, 2019, until December 31, 2019. The study population included 24,950 patients presenting to Romanian public hospitals in all 41 counties: ≥ the age of 40 with diagnostic ICD 10 codes: S72.0 femoral neck fracture, S72.1 pertrochanteric femoral fracture, and S72.2 subtrochanteric femoral fracture and procedure codes: O11104 (trochanteric/sub capital internal fixation), O12101 (hemiarthroplasty), O11808 (closed femoral reduction with internal fixation), O12103 (partial arthroplasty), O12104 (total arthroplasty). Hospital length of stay (LoS) was classified as follows: < 6, 6-9, 10-14, and ≥ 15 days.

RESULTS

Incidence of hip fractures was 248/100,000 among those aged 50 + and 184/100,000 within the 40 + age category. Average age of the patients was 77 years (80 for females, 71 for males); 83.7% of the patients were 65 + with equivalent urban-rural distributions. Males had a 1.7 times higher mortality risk. Each year increase in age added a mortality risk of 6.9%. In-hospital mortality was 1.34 times higher among patients living in urban areas. Hemiarthroplasty and partial/total unilateral/bilateral arthroplasty had a lower risk of mortality than trochanteric/sub capital internal fixation (p < 0.02, p < 0.033).

CONCLUSION

Gender, age, residence, and procedure type had significant impact on mortality. Updated incidence rates will allow the revision of Romania's FRAX model.

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

BACKGROUND

Mortality rates among men are double that of women in the first 2 years after hip fracture and may be related to more infections. Research has only examined differences in short-term mortality after hip fracture. Thus, the objective was to determine if long-term all-cause mortality and infection-specific mortality rates are higher in men compared to women.

METHODS

Data come from a prospective cohort study (Baltimore Hip Studies 7th [BHS-7]) with up to 10.2 years of follow-up (2006-2018). The participants were selected from eight acute care hospitals in the 25-hospital BHS network. Enrolled women were frequency-matched (1:1) to men on timing of admission for hip fracture that yielded an analytic sample size of 300 participants (155 women, 145 men). Associations between sex and mortality were analyzed using Cox proportional hazard models and cause-specific Cox models adjusted for age, cognition, body mass index, pre-fracture lower extremity activities of daily living limitation, depressive symptoms, and comorbidity.

RESULTS

Participants had a mean age of 80 years, 48% (n = 145) were men and the median follow-up was 4.9 (interquartile range = 2.3-8.7) years. Over the follow-up period after hospital admission for hip fracture, 237 (79.0%) participants died of all causes (132 men and 105 women) and 38 (12.7%) died of infection-specific causes (25 men and 13 women). Men had significantly higher rates of all-cause mortality [hazard ratio (HR) = 2.31(95% confidence interval [CI] 2.02-2.59)] and infection-specific mortality (HR = 4.43, CI 2.07-9.51) compared to women.

CONCLUSIONS

Men had a two-fold higher rate of all-cause mortality and four-fold higher rate of infection-specific mortality compared to women over a follow-up period of up to 10.2 years. Findings suggest that interventions to prevent and treat infections, tailored by sex, may be needed to narrow significant differences in long-term mortality rates between men and women after hip fracture.

Differential misclassification of cognitive impairment by sex among hip fracture patients

BACKGROUND

Males have worse outcomes after hip fracture than female counterparts. Cognitive impairment (CI) also increases the risk of poor recovery from hip fracture; however, CI is under-recognized. Patient sex may contribute to this under-recognition through differential misclassification. The objective of this study was to measure under-recognition and differential misclassification of CI by patient sex.

METHODS

A cross-sectional analysis of baseline data from an observational cohort study of community-dwelling hip fracture patients aged 65 and older (n = 339; females = 171, males = 168) recruited from eight hospitals in the greater Baltimore, MD area within 15 days of hospitalization for surgical repair with cognitive testing within 22 days of admission. Indication of Alzheimer's disease or related dementias and/or delirium as a postoperative complication in the medical record was considered evidence of documented CI. Observed CI was measured with the Modified Mini-Mental State Examination (3MS, ≤78). Source of cognitive impairment identification (SCI) was defined as: "3MS Only," "Hospital Record Only," "Both," "No CI" was compared between males and females using logistic regression.

RESULTS

Males had more comorbidities and worse physical status upon admission, but otherwise had similar hospital experiences. SCI distribution was 12.7% "3MS Only" (n = 42), 11.5% "Hospital Record Only" (n = 38), 9.4% "Both" (n = 31), and "No CI" (n = 219). Males were more likely to be identified with CI using the "3MS Only" and "Both," and females were more likely to have no indication of CI.

CONCLUSION

There were sex differences in the documentation of CI versus observed impairment. Males had more CI using direct testing. This may be contributing to sex differences in recovery outcomes after hip fracture. Results support the implementation of cognitive testing in hip fracture patients to reduce the impact of differential misclassification by patient sex.

Change in vertebral strength and bone mineral density in men and women over the year post-hip fracture: a subgroup analysis

This study examines changes in bone density and strength in the spine over the year after hip fracture to see if there are differences in the changes between men and women. Results show losses in the spine that may increase the risk of subsequent vertebral fractures, particularly for women.

PURPOSE

Compare changes over the first year post-hip fracture in vertebral bone mineral density (BMD) and compressive strength, measured from quantitative computed tomography (QCT) scans of the spine (T12-L1), between women and men.

METHODS

QCT scans were performed on 37 participants (21 men and 16 women) at 2 and 12 months post-hip fracture as part of an ancillary observational study of hip fracture recovery in older community-dwelling men and women. Vertebral BMD and compressive strength were calculated using VirtuOst® (O.N. Diagnostics, Berkeley, CA). Unpaired t-tests were used to compare men and women with respect to baseline demographics, measurements of BMD and bone strength for the whole vertebra and the cortical and trabecular compartments, and any changes in these parameters between months 2 and 12.

RESULTS

At 2 months post-fracture, there were no significant sex differences in any measurements of vertebral strength or BMD. Between months 2 and 12, vertebral strength decreased significantly in women (- 3.8%, p < 0.05) but not in men (- 2.3%, p < 0.20), vertebral trabecular BMD decreased similarly in both sexes (- 5.7% women; - 6.0% men), but cortical BMD did not change for either sex.

CONCLUSION

Despite the small sample size, these findings suggest that appreciable loss of vertebral trabecular bone can occur for both sexes in the year following hip fracture, which may increase the risk of subsequent vertebral fracture, particularly for women.

Application of SDOC Cut Points for Low Muscle Strength for Recovery of Walking Speed After Hip Fracture

BACKGROUND

Sarcopenia is often conceptualized as a precursor to loss of mobility, but its effect on recovery of mobility after a hip fracture is unknown. We determined the prevalence of low muscle strength (weakness) after hip fracture using putative sarcopenia metrics (absolute grip strength, and grip strength normalized to body mass index, total body fat, arm lean mass, and weight) identified by the Sarcopenia Definitions and Outcomes Consortium (SDOC).

METHODS

We examined two well-characterized hip fracture cohorts of community-dwelling older adults from the Baltimore Hip Studies (BHS). The prevalence of muscle weakness was assessed using the SDOC cut points compared to published definitions at 2 and 6 months postfracture. We assessed associations of 2-month weakness with 6-month walking speed <0.6 m/s and calculated the sensitivity and specificity in predicting lack of meaningful change in walking speed (change < 0.1 m/s) at 6 months.

RESULTS

Two hundred and forty-six participants (192 women; 54 men) were included; mean (SD) age of 81 (8) for women and 78 (7) for men. At 2 months, 91% women and 78% men exhibited slow walking speed (< 0.6 m/s). SDOC grip strength standardized by weight (<0.34 kg women, <0.45 kg men) was the most prevalent measure of weakness in men (74%) and women (79%) and provided high sensitivity in men (86%) and women (84%) predicting lack of meaningful change in walking speed at 6 months, although specificity was poor to moderate.

CONCLUSIONS

SDOC cut points for grip strength standardized to weight provided consistent indication of poor walking speed performance post-hip fracture.

Biomarkers Associated with Physical Resilience After Hip Fracture

BACKGROUND

Clinically similar older adults demonstrate variable responses to health stressors, heterogeneity attributable to differences in physical resilience. However, molecular mechanisms underlying physical resilience are unknown. We previously derived a measure of physical resilience after hip fracture-the expected recovery differential (ERD)-that captures the difference between actual recovery and predicted recovery. Starting with biomarkers associated with physical performance, morbidity, mortality, and hip fracture, we evaluated associations with the ERD to identify biomarkers of physical resilience after hip fracture.

METHODS

In the Baltimore Hip Studies (N = 304) sera, we quantified biomarkers of inflammation (TNFR-I, TNFR-II, sVCAM-1, and IL-6), metabolic and mitochondrial function (non-esterified fatty acids, lactate, ketones, acylcarnitines, free amino acids, and IGF-1), and epigenetic dysregulation (circulating microRNAs). We used principal component analysis, canonical correlation, and least absolute shrinkage and selection operator regression (LASSO) to identify biomarker associations with better-than-expected recovery (greater ERD) after hip fracture.

RESULTS

Participants with greater ERD were more likely to be women and less disabled at baseline. The complete biomarker set explained 37% of the variance in ERD (p < .001) by canonical correlation. LASSO regression identified a biomarker subset that accounted for 27% of the total variance in the ERD and included a metabolic factor (aspartate/asparagine, C22, C5:1, lactate, glutamate/mine), TNFR-I, miR-376a-3p, and miR-16-5p.

CONCLUSIONS

We identified a set of biomarkers that explained 27% of the variance in ERD-a measure of physical resilience after hip fracture. These ERD-associated biomarkers may be useful in predicting physical resilience in older adults facing hip fracture and other acute health stressors.

Comparing Longitudinal Sarcopenia Trends by Definitions Across Men and Women After Hip Fracture

OBJECTIVES

While sarcopenia is prevalent after hip fracture in the acute postfracture period, little is known about the prevalence after discharge. This study assessed longitudinal trends in sarcopenia prevalence over 12 months after hip fracture using three different operational definitions.

DESIGN

Prospective observational study.

SETTING

Baltimore Hip Studies seventh cohort.

PARTICIPANTS

A total of 82 men and 78 women, aged 65 years and older, with surgical repair of a nonpathological hip fracture.

MEASUREMENTS

Baseline assessment included a dual-energy X-ray absorptiometry scan and interview. Follow-up assessments, which additionally included performance measures, occurred 2, 6, and 12 months after admission. Using these measures, three sarcopenia definitions were assessed over the year following hip fracture: European Working Group on Sarcopenia in Older Persons (EWGSOP), International Working Group on Sarcopenia (IWGS), and Foundation for the National Institutes of Health (FNIH).

RESULTS

EWGSOP and IWGS provided the highest prevalence of sarcopenia (62%-69% in men, 42%-62% in women), while prevalence by FNIH was much lower for men (15%-19%) and women (5%-12%). For both men and women, the agreement between EWGSOP and IWGS definitions was excellent, and FNIH showed poor agreement with them, supported by various statistical measures across first-year follow-up. Prevalence was stable over time in men by all definitions, while the prevalence in women by FNIH was lowest at 2 months, significantly increased at 6 months (P = .03), and remained higher at 12 months. Whether sarcopenia prevalence differed significantly by sex varied by time point and definition; however, when different, men had a higher prevalence than women (P < .05). While some participants recovered from sarcopenia over time, some also became newly sarcopenic.

CONCLUSION

The prevalence of sarcopenia after fracture differed greatly for EWGSOP and IWGS compared to FNIH. Overall, there appeared to be no reduction in sarcopenia over the year after hip fracture, regardless of definition. Future research should examine the relationship between sarcopenia prevalence and functional recovery. J Am Geriatr Soc 68:1537-1544, 2020.

Two Approaches to Classifying and Quantifying Physical Resilience in Longitudinal Data

BACKGROUND

Approaches for quantifying physical resilience in older adults have not been described.

METHODS

We apply two conceptual approaches to defining physical resilience to existing longitudinal data sets in which outcomes are measured after an acute physical stressor. A "recovery phenotype" approach uses statistical methods to describe how quickly and completely a patient recovers. Statistical methods using a recovery phenotype approach can consider multiple outcomes simultaneously in a composite score (eg, factor analysis and principal components analysis) or identify groups of patients with similar recovery trajectories across multiple outcomes (eg, latent class profile analysis). An "expected recovery differential" approach quantifies how patients' actual outcomes are compared to their predicted outcome based on a population-derived model and their individual clinical characteristics at the time of the stressor.

RESULTS

Application of the approaches identified different participants as being the most or least physically resilient. In the viral respiratory cohort (n = 186) weighted kappa for agreement across resilience quartiles was 0.37 (0.27-0.47). The expected recovery differential approach identified a group with more comorbidities and lower baseline function as highly resilient. In the hip fracture cohort (n = 541), comparison of the expected recovery differentials across 10 outcome measures within individuals provided preliminary support for the hypothesis that there is a latent resilience trait at the whole-person level.

CONCLUSIONS

We posit that recovery phenotypes may be useful in clinical applications such as prediction models because they summarize the observed outcomes across multiple measures. Expected recovery differentials offer insight into mechanisms behind physical resilience not captured by age and other comorbidities.

Differences in geometric strength at the contralateral hip between men with hip fracture and non-fractured comparators

Older men sustain excess bone mineral density (BMD) declines after hip fracture; however, BMD provides no information on mechanical structure and strength. The aim was to assess whether changes in hip bone geometry in older men after hip fracture differ than that expected with aging. Two cohorts were used: Baltimore Hip Studies 7th cohort (BHS-7) and Baltimore Men's Osteoporosis Study (MOST). The sample (N = 170) included older Caucasian men with hip fracture that were propensity score matched (1:1) to community-dwelling non-fractured comparators. Hip Structural Analysis (HSA) calculated aerial BMD and metrics of bone structural strength: cross-sectional bone area (CSA), cortical outer diameter (OD), section modulus (SM), and centroid position (CP). Mixed-effect models estimated changes in HSA parameters and adjusted robust regression models evaluated between-cohort differences in annual percent change at the narrow neck (NN), intertrochanteric (IT), and femoral shaft (FS). Hip fracture was associated with statistically greater declines in NN CSA (β = -2.818; 95% CI: -3.300%, -2.336%), SM (β = -1.896%; 95% CI: -2.711%, -1.080%) and CP (β = -0.884%; 95% CI: -0.889%, -0.880%) and significantly larger increases in NN OD (β = 0.187%; 95% CI: 0.185%, 0.190%). Differences in IT HSA parameters were like the NN but larger in magnitude, while there were favorable changes in FS geometry where fragility fractures are rare. Findings indicate there are declines in bone structure and strength at the NN and IT regions of the proximal femur in older men during hip fracture recovery that far exceed what occurs during normal aging.

Resiliency Groups Following Hip Fracture in Older Adults

OBJECTIVES

Defining common patterns of recovery after an acute health stressor (resiliency groups) has both clinical and research implications. We sought to identify groups of patients with similar recovery patterns across 10 outcomes following hip fracture (stressor) and to determine the most important predictors of resiliency group membership.

DESIGN

Secondary analysis of three prospective cohort studies.

SETTING

Participants were recruited from various hospitals in the Baltimore Hip Studies network and followed for up to 1 year in their residence (home or facility).

PARTICIPANTS

Community-dwelling adults aged 65 years or older with recent surgical repair of a hip fracture (n = 541).

MEASUREMENTS

Self-reported physical function and activity measures using validated scales were collected at baseline (within 15-22 d of fracture), 2, 6, and 12 months. Physical performance tests were administered at all follow-up visits. Stressor characteristics, comorbidities, and psychosocial and environmental factors were collected at baseline via participant report and chart abstraction. Latent class profile analysis was used to identify resiliency groups based on recovery trajectories across 10 outcome measures and logistic regression models to identify factors associated with those groups.

RESULTS

Latent profile analysis identified three resiliency groups that had similar patterns across the 10 outcome measures and were defined as "high resilience" (n = 163 [30.1%]), "medium resilience" (n = 242 [44.7%]), and "low resilience" (n = 136 [25.2%]). Recovery trajectories for the outcome measures are presented for each resiliency group. Comparing highest with the medium- and low-resilience groups, self-reported pre-fracture function was by far the strongest predictor of high-resilience group membership with area under the curve (AUC) of .84. Demographic factors, comorbidities, stressor characteristics, environmental factors, and psychosocial characteristics were less predictive, but several factors remained significant in a multivariable model (AUC = .88).

CONCLUSION

These three resiliency groups following hip fracture may be useful for understanding mediators of physical resilience. They may provide a more detailed description of recovery patterns in multiple outcomes for use in clinical decision making. J Am Geriatr Soc 67:2519-2527, 2019.

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

OBJECTIVE

To examine trends in 12-month postfracture residual disability, nursing home placement, and mortality among patients with a hip fracture between 1990 and 2011.

DESIGN

Secondary analysis of 12-month outcomes from 3 cohort studies and control arms of 2 randomized controlled trials.

SETTING

Original studies were conducted as part of the Baltimore Hip Studies (BHS).

PARTICIPANTS

Community-dwelling patients ≥65 years of age hospitalized for surgical repair of a nonpathologic hip fracture (N=988).

MAIN OUTCOME MEASURES

Twelve-month residual disability, mortality, and nursing home residency were examined in case-mix adjusted models by sex and study. Residual disability was calculated by subtracting prefracture scores of Lower Extremity Physical Activities of Daily Living from scores at 12 months postfracture. We also examined the proportion of individuals with a 12-month score higher than their prefracture score (residual disability>0).

RESULTS

Only small improvements were seen in residual disability between 1990 and 2011. No significant differences were seen for men between BHS2 (enrollment 1990-1991; mean residual disability=3.1 activities; 95% confidence interval [CI], 2.16-4.10) and BHS7 (enrollment 2006-2011; mean=3.1 activities; 95% CI, 2.41-3.82). In women, residual disability significantly improved from BHS2 (mean=3.5 activities; 95% CI, 2.95-3.99) to BHS3 (enrollment 1992-1995; mean=2.7 activities; 95% CI, 2.01-3.30) with no significant improvements in later studies. After adjustment, a substantial proportion (91% of men and 79% of women) had a negative outcome (residual disability, died, or nursing home residence at 12 months) in the most recently completed study (BHS7).

CONCLUSIONS

Over 2 decades, patients undergoing usual care post-hip fracture still had substantial residual disability. Additional clinical and research efforts are needed to determine how to improve hip fracture treatment, rehabilitation, and subsequent outcomes.