JMIR Publications

ABSTRACT

Background:

To improve postoperative patient survival, particularly in older adults, the predictors of mortality following hip fracture must be identified. Air pollution is a pressing global environmental concern, which increases the rates of morbidity and mortality from various diseases. However, the effects of air pollution on the outcomes of hip fracture remain unclear.

Objective:

This retrospective study was conducted to investigate the effects of decade-long exposure to 12 air pollutants on the risk of mortality after hip fracture surgery in older Taiwanese patients (age > 60 years). We hypothesized that long-term exposure to air pollution would increase the rate of 1-year mortality after hip fracture surgery.

Methods:

From Taiwan’s National Health Insurance Research Database, we obtained the data of patients who underwent hip fracture surgery between July 1, 2003, and December 31, 2013. Using the patients’ insurance registration data, we estimated their levels of exposure to SO2, CO2, CO, O3, PM10, PM2.5, NOX, NO, NO2, total hydrocarbons (THC), nonmethane hydrocarbons (NMHC), and CH4. The dose–response effects between air pollutants and mortality risk were evaluated by calculating the hazard ratios (HRs) for exposure at 1 standard deviation (SD) increment for 10 years.

Results:

Long-term exposure to SO2, CO, PM10, PM2.5, NOX, NO, NO2, THC, NMHC, and CH4 was associated with an increased risk of all-cause mortality within 1 year after hip fracture surgery. In older adults, 1 SD increment in the average exposure levels of SO2, CO, PM10, PM2.5, NOX, NO, NO2, THC, NMHC, and CH4 was associated with 15%, 49%, 19%, 12%, 41%, 33%, 38%, 21%, 9%, and 27% increases in mortality risk, respectively. We further noted a 36% reduction in the HR for ozone and a trend of potentially protective effects of CO2.

Conclusions:

This nationwide population-based retrospective study revealed that long-term exposure to specific air pollutants is associated with an increased risk of all-cause mortality within 1 year after hip fracture surgery in older Taiwanese adults. A reduction in the levels of SO2, CO, PM10, PM2.5, NOX, NO, NO2, THC, NMHC, and CH4 may reduce the risk of mortality after hip fracture surgery. This study provides robust evidence and highlights the effects of air pollution on the outcomes of hip fracture.