Quality of life related to fear of falling and hip fracture in older women: a time trade off study.(Statistical Data Included)

Abstract

Objective To estimate the utility (preference for health) associated with hip fracture and fear of falling among older women.

Design Quality of life survey with the time trade off technique. The technique derives an estimate of preference for health states by finding the point at which respondents show no preference between a longer but lower quality of life and a shorter time in full health.

Setting A randomised trial of external hip protectors for older women at risk of hip fracture.

Participants 194 women aged [is greater than or equal to] 75 years enrolled in the randomised controlled trial or who were eligible for the trial but refused completed a quality of life interview face to face.

Outcome measures Respondents were asked to rate their own health by using the Euroqol instrument and then rate three health states (fear of falling, a "good" hip fracture, and a "bad" hip fracture) by using time trade off technique.

Results On an interval scale between 0 (death) and 1 (full health), a "bad" hip fracture (which results in admission to a nursing home) was valued at 0.05; a "good" hip fracture (maintaining independent living in the community) 0.31, and fear of falling 0.67. Of women surveyed, 80% would rather be dead (utility = 0) than experience the loss of independence and quality of life that results from a bad hip fracture and subsequent admission to a nursing home. The differences in mean utility weights between the trial groups and the refusers were not significant. A test-retest study on 36 women found that the results were reliable with correlation coefficients within classes ranging from 0.61 to 0.88.

Conclusions Among older women who have exceeded average life expectancy, quality of life is profoundly threatened by falls and hip fractures. Older women place a very high marginal value on their health. Any loss of ability to live independently in the community has a considerable detrimental effect on their quality of life.

Introduction

Hip fractures are a major cause of morbidity and mortality, and almost all occur after a fall.[1] In the next 50 years the number of hip fractures will probably increase greatly.[1-3] About 20% of people who fracture their hips are dead within a year,[4-6] and many of those who recover from hip fracture require additional assistance in daily living.[4 7] Population data tend to obscure the personal impact of falls and hip fracture. Objective measures of function, such as activities of daily living[8] and subjective utility based measures of health related quality of life,[9] can express the personal dimension. Hip fracture adversely affects health related quality of life, with greater physical recovery reflected in better quality of life.[10] Thus, health related quality of life is an important outcome for studies attempting to reduce the number of falls or their consequences.[11] As part of an ongoing randomised trial (the community hip protector trial) that is examining the effectiveness of hip protectors in older women living in the community we sought to estimate the utility (preference for health) associated with falls that cause a fear of falling or hip fracture in older women.

Methods

Study participants--The community hip protector study is a randomised controlled trial involving women aged 75 years and older who are at high risk of hip fracture and who live in their own homes. Older women living in the northern suburbs of Sydney, Australia, who had contact with an aged care health service and met inclusion criteria were invited to participate in the study. These criteria were age greater than 74 years; two or more falls, or one fall resulting in hospital treatment, in the past year; at least one hip without previous surgery; likely to continue to live in the community for at least three months; likely to survive for at least one year; English speaker; and able to give informed consent.[12] A sample of women from the hip protector trial as well as a group of women who had refused to participate in the trial were approached to participate in the quality of life study. The sample included all women randomised into the trial (or who refused to enter the trial) from April 1997 to July 1998. Thus the study elicited values from women who had direct experience in wearing the hip protectors (the intervention group), women who did not have experience in wearing the hip protectors but were aware of the trial (the control group), and women who had refused to participate in the trial because they would not wear the hip protectors if randomised to the intervention group (refusers). The study was approved by the ethics committees of participating hospitals. The quality of life interview schedule was administered to the women six months after they were recruited into the trial (or after refusal to enter).

Health states--To develop descriptions of health states we reviewed the literature and interviewed older women. Sixteen open ended quality of life interviews were conducted with women who had had no contact at all with trial and who had experienced a hip fracture. The interviews helped to define the dimensions of quality of life most affected by a hip…