Objective: to examine the association between residential status and risk o
f hip fracture in older people.
Design: population-based case-control study.
Setting: Auckland, New Zealand.
Subjects: a random sample of all individuals greater than or equal to 60 ye
ars, hospitalized with a fracture of the proximal femur between July 1991 a
nd February 1994. Controls were age and gender frequency-matched to the cas
es, randomly selected from a random sample of general practitioners.
Main outcome measures: radiographically-confirmed fracture of the proximal
femur. Fractures sustained as a result of major trauma, such as in a motor
vehicle crash, and those associated with pre-existing pathological conditio
ns were excluded.
Results: individuals living in institutions were almost four times more Lik
ely to sustain a hip fracture [age- and gender-adjusted odds ratio (OR) = 3
.8; 95% confidence interval (CT): 3.0-4.8] than those living in private hom
es. After adjustment for potential confounding factors, the risk of hip fra
cture associated with living in an institution remained significantly incre
ased (P < 0.0001), although the magnitude of the risk was somewhat diminish
ed (OR = 2.2; 95% CI: 1.5-3.5).
Conclusions: living in an institution is associated with an increased risk
of hip fracture in older people. Specific factors that place these individu
als at increased risk need to be identified, in order to develop interventi