Air temperature and the incidence of fall-related hip fracture hospitalisations in older people.
Observation-driven Poisson regression models were used to investigate mean daily air temperature and fall-related hip fracture hospitalisations. After adjustment for season, day-of-week effects, long-term trend and autocorrelation, hip fracture rates are higher in both males and females aged 75+ years when there is a lower air temperature.


BACKGROUND
This study investigated whether there was an association between fall-related hip fracture hospitalisations and air temperature at a day-to-day level, after accounting for seasonal trend and autocorrelation.


METHODS
Observation-driven Poisson regression models were used to investigate mean daily air temperature and fall-related hip fracture hospitalisations for the period 1 July 1998 to 31 December 2004, inclusive, in the Sydney region of New South Wales, Australia, which has a population of 4 million people.


RESULTS
Lower daily air temperature was significantly associated with higher fall-related hip fracture hospitalisations in 75+-year-olds: men aged 75-84 years, rate ratio (RR) for a 1°C increase in temperature of 0.98 with 95% confidence interval (0.96, 0.99), men 85+ years RR = 0.98 (0.96, 1.00), women 75-84 years RR = 0.99 (0.98, 1.00), women 85+ years RR = 0.98 (0.97, 0.99). Moreover, there were fewer hospitalisations on weekends compared to weekdays ranging from RR = 0.81 (0.73, 0.90) in women aged 65-74 years to RR = 0.89 (0.80, 0.98) in men aged 85+ years.


CONCLUSIONS
After adjustment for season, day-of-week effects, long-term trend and autocorrelation, fall-related hip fracture hospitalisation rates are higher in both males and females aged 75+ years when there is a lower air temperature.
NSW Injury Risk Research Management Centre, University of New South Wales, Sydney, Australia.
R M
RM
Turner
A
A
Hayen
W T M
WT
Dunsmuir
C F
CF
Finch
D000058:Accidental Falls / Q000706:statistics & numerical data*; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D003080:Cold Temperature / Q000009:adverse effects; D005260:Female; D006620:Hip Fractures / Q000453:epidemiology* / Q000209:etiology; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D008297:Male; D009517:New South Wales / Q000453:epidemiology; D017678:Sex Distribution; D013696:Temperature