Temporal trends in fracture rates and postdischarge outcomes among hemodialysis patients

Abstract

Patients with ESRD have a substantially increased risk of bone fractures, but the burden of fractures has not been sufficiently characterized in this population. Here, we analyzed fracture rates and postdischarge outcomes using Medicare data from hemodialysis patients in the United States between 2000 and 2009. We assessed adjusted quarterly fracture rates (inpatient and outpatient) and consequences of postfracture hospitalization for seven categories of fracture location. Pelvis/hip, vertebral, and lower leg fractures were the most prevalent fracture types. Pelvis/hip fractures declined slightly from 29.6 to 20.6 per 1000 patient-years between early 2000 and late 2009, but the incidence rates for all other fracture types remained relatively constant. Median lengths of stay for the primary fracture hospitalization ranged from 5 days (interquartile range [IQR], 3-9 days) for forearm/wrist fractures to 8 days (IQR, 5-12 days) for femur fractures. The proportion of patients discharged from the primary hospitalization to a skilled-nursing facility ranged from 28% (ribs/sternum) to 47% (pelvis/hip). A negative binomial regression model suggested that patients had an adjusted mean of 3.8-5.2 additional hospitalizations during the year after discharge from the index hospitalization, varying by fracture type, comprising a mean of 33-52 inpatient days. Case-mix-adjusted mortality rates after discharge ranged from 0.43 to 0.91 per patient-year and were highest for vertebral, pelvis/hip, and femur fractures. In conclusion, fractures in the dialysis population are common and are associated with a substantially increased risk for death and hospitalization.

Figure 1.

Adjusted fracture incidence rates remained constant in the years 2000–2009. Rates were highest for pelvis/hip, vertebral, and lower leg fracture categories. All trend lines were adjusted for age, race, sex, cause of ESRD, and years on dialysis. (A) Inpatient and outpatient fractures. (B) Inpatient fractures only.

Figure 2.

Adjusted fracture incidence rates by strata for the top three most prevalent fracture categories (pelvis/hip, vertebral, lower leg) in years 2000–2009. Rates were adjusted for age, race, sex, cause of ESRD and years on dialysis. The subgroup of interest was omitted from the adjustment for each respective subgroup category.

Figure 3.

Following discharge from pelvis/hip fracture hospitalization, rates of mortality, readmission, and SNF admission increased with age, were similar for both sexes, and were slightly higher for whites than other races in years 2000–2009. Events per patient-year are presented for each respective event.