Predictors of refusal to participate: a longitudinal health survey of the elderly in Australia

BACKGROUND: The loss of participants in longitudinal studies due to non-contact, refusal or death can introduce bias into the results of such studies. The study described here examines reasons for refusal over three waves of a survey of persons aged ≥ 70 years. METHODS: In a longitudinal study involving three waves, participants were compared to those who refused to participate but allowed an informant to be interviewed and to those who refused any participation. RESULTS: At Wave 1 both groups of Wave 2 non-participants had reported lower occupational status and fewer years of education, had achieved lower verbal IQ scores and cognitive performance scores and experienced some distress from the interview. Those with an informant interview only were in poorer physical health than those who participated and those who refused. Depression and anxiety symptoms were not associated with non-participation. Multivariate analyses found that verbal IQ and cognitive impairment predicted refusal. Results were very similar for refusers at both Waves 2 and 3. CONCLUSIONS: Longitudinal studies of the elderly may over estimate cognitive performance because of the greater refusal rate of those with poorer performance. However, there is no evidence of bias with respect to anxiety or depression

Predictors of refusal to participate: a longitudinal health survey of the elderly in Australia

<p>Abstract</p> <p>Background</p> <p>The loss of participants in longitudinal studies due to non-contact, refusal or death can introduce bias into the results of such studies. The study described here examines reasons for refusal over three waves of a survey of persons aged ≥ 70 years.</p> <p>Methods</p> <p>In a longitudinal study involving three waves, participants were compared to those who refused to participate but allowed an informant to be interviewed and to those who refused any participation.</p> <p>Results</p> <p>At Wave 1 both groups of Wave 2 non-participants had reported lower occupational status and fewer years of education, had achieved lower verbal IQ scores and cognitive performance scores and experienced some distress from the interview. Those with an informant interview only were in poorer physical health than those who participated and those who refused. Depression and anxiety symptoms were not associated with non-participation. Multivariate analyses found that verbal IQ and cognitive impairment predicted refusal. Results were very similar for refusers at both Waves 2 and 3.</p> <p>Conclusions</p> <p>Longitudinal studies of the elderly may over estimate cognitive performance because of the greater refusal rate of those with poorer performance. However, there is no evidence of bias with respect to anxiety or depression.</p

Association of obesity with anxiety, depression and emotional well‐being: a community survey

Abstract Objective:To investigate the association of obesity with anxiety, depression and emotional well‐being (positive and negative affect) in three age groups. Methods:A cross‐sectional survey was carried out in Canberra and the neighbouring town of Queanbeyan, Australia, with a random sample from the electoral roll of 2,280 persons aged 20–24, 2,334 aged 40–44, and 2,305 aged 60–64. Results:Self‐reported height and weight were used to classify participants as underweight (body mass index of less than 18.5), acceptable weight (18.5 to less than 25), overweight (25 to less than 30) or obese (30 and over). Obesity in women was associated with more anxiety and depression symptoms and less positive affect, but there were only weak and inconsistent associations in men. When factors that might mediate any association were controlled (physical ill health, lack of physical activity, poorer social support, less education and financial problems), a different picture emerged, with the underweight women having more depression and negative affect and the obese and overweight women tending to have better mental health than the acceptable weight group. Controlling for physical ill health alone accounted for the association of obesity with anxiety and depression in women. Conclusions:Obesity has an association with anxiety, depression and lower well‐being in women, but not in men. The results are consistent with physical ill health playing a mediating role. Implication:Reducing obesity in the population is unlikely to have any direct effect on mental health or emotional well‐being

Association of obesity with anxiety, depression and emotional well‐being: a community survey

Abstract Objective:To investigate the association of obesity with anxiety, depression and emotional well‐being (positive and negative affect) in three age groups. Methods:A cross‐sectional survey was carried out in Canberra and the neighbouring town of Queanbeyan, Australia, with a random sample from the electoral roll of 2,280 persons aged 20–24, 2,334 aged 40–44, and 2,305 aged 60–64. Results:Self‐reported height and weight were used to classify participants as underweight (body mass index of less than 18.5), acceptable weight (18.5 to less than 25), overweight (25 to less than 30) or obese (30 and over). Obesity in women was associated with more anxiety and depression symptoms and less positive affect, but there were only weak and inconsistent associations in men. When factors that might mediate any association were controlled (physical ill health, lack of physical activity, poorer social support, less education and financial problems), a different picture emerged, with the underweight women having more depression and negative affect and the obese and overweight women tending to have better mental health than the acceptable weight group. Controlling for physical ill health alone accounted for the association of obesity with anxiety and depression in women. Conclusions:Obesity has an association with anxiety, depression and lower well‐being in women, but not in men. The results are consistent with physical ill health playing a mediating role. Implication:Reducing obesity in the population is unlikely to have any direct effect on mental health or emotional well‐being