Jennifer R. Powers

Attrition in longitudinal studies: who do you lose?

Objective: To describe the risk factors for various types of attrition in three age cohorts of women in a longitudinal study and to discuss strategies to minimise attrition.

Effectiveness of the National Death Index for establishing the vital status of older women in the Australian Longitudinal Study on Women's Health

Objective:To assess the effectiveness of the National Death Index (NDI) in identifying participants in the oldest cohort of the Australian Longitudinal Study on Womens Health (ALSWH) who had died between 1996 and 1998.

The Impact of Attrition in an 11-Year Prospective Longitudinal Study of Younger Women

PURPOSE To investigate the impact of attrition on prevalence and associations between variables across four waves of a longitudinal study. METHODS Prevalence of socio-demographic and health characteristics were estimated for respondents to one, two, three or all four waves of the Australian Longitudinal Study of Womens Health cohort born between 1973 and 1978. Associations with self-rated General Health (GH) and Mental Health (MH) were compared using fixed effects in separate mixed models for respondents to at least one wave, at least two waves, at least three waves, or four waves of the longitudinal study. RESULTS 14,247 women aged 18-23 years responded to Wave 1 in 1996. Respondents to all waves were more educated, and less likely to be stressed about money, to be smokers and to have children than respondents to some waves. Across all models, better GH was consistently associated with more education, no monetary stress, being married, having children, fewer visits to the doctor and not smoking. Similar results were obtained for MH. CONCLUSIONS Although the potential for bias due to attrition must be considered, the current paper contributes to the growing body of evidence that suggests such biases are insufficient to preclude meaningful longitudinal analyses.

Iron deficiency, general health and fatigue: Results from the Australian Longitudinal Study on Women's Health

Associations between self-reported ‘low iron’, general health and well-being, vitality and tiredness in women, were examined using physical (PCS) and mental (MCS) component summary and vitality (VT) scores from the MOS short-form survey (SF-36). 14,762 young (18–23 years) and 14,072 mid-age (45–50 years) women, randomly selected from the national health insurance commission (Medicare) database, completed a baseline mailed self-report questionnaire and 12,328 mid-age women completed a follow-up questionnaire 2 years later. Young and mid-age women who reported (ever) having had ‘low iron’ reported significantly lower mean PCS, MCS and VT scores, and greater prevalence of ‘constant tiredness’ at baseline than women with no history of iron deficiency [Differences: young PCS = −2.2, MCS = −4.8, VT = −8.7; constant tiredness: 67% vs. 45%; mid-age PCS = −1.4, MCS = −3.1, VT = −5.9; constant tiredness: 63% vs. 48%]. After adjusting for number of children, chronic conditions, symptoms and socio-demographic variables, mean PCS, MCS and VT scores for mid-age women at follow-up were significantly lower for women who reported recent iron deficiency (in the last 2 years) than for women who reported past iron deficiency or no history of iron deficiency [Means: PCS – recent = 46.6, past = 47.8, never = 47.7; MCS – recent = 45.4, past = 46.9, never = 47.4; VT – recent = 54.8, past = 57.6, never = 58.6]. The adjusted mean change in PCS, MCS and VT scores between baseline and follow-up were also significantly lower among mid-age women who reported iron deficiency only in the last 2 years (i.e. recent iron deficiency) [Mean change: PCS = −3.2; MCS = −2.1; VT = −4.2]. The results suggest that iron deficiency is associated with decreased general health and well-being and increased fatigue.

How does the health and well-being of young Australian vegetarian and semi-vegetarian women compare with non-vegetarians?

OBJECTIVE To compare the sociodemographic characteristics, health status and health service use of vegetarians, semi-vegetarians and non-vegetarians. DESIGN In cross-sectional data analyses of the Australian Longitudinal Study on Womens Health in 2000, 9113 women (aged 22-27 years) were defined as non-vegetarians if they reported including red meat in their diet, as semi-vegetarians if they excluded red meat and as vegetarians if they excluded meat, poultry and fish from their diet. RESULTS The estimated prevalence was 3% and 10% for vegetarian and semi-vegetarian young women. Compared with non-vegetarians, vegetarians and semi-vegetarians were more likely to live in urban areas and to not be married. Vegetarians and semi-vegetarians had lower body mass index (mean (95% confidence interval): 22.2 (21.7-22.7) and 23.0 (22.7-23.3) kg m(-2)) than non-vegetarians (23.7 (23.6-23.8) kg m(-2)) and tended to exercise more. Semi-vegetarians and vegetarians had poorer mental health, with 21-22% reporting depression compared with 15% of non-vegetarians (P < 0.001). Low iron levels and menstrual symptoms were also more common in both vegetarian groups. Vegetarian and semi-vegetarian women were more likely to consult alternative health practitioners and semi-vegetarians reported taking more prescription and non-prescription medications. Compared with non-vegetarians, semi-vegetarians were less likely and vegetarians much less likely to be taking the oral contraceptive pill. CONCLUSION The levels of physical activity and body mass indices of the vegetarian and semi-vegetarian women suggest they are healthier than non-vegetarians. However, the greater reports of menstrual problems and the poorer mental health of these young women may be of clinical significance.

Number of social roles, health, and well-being in three generations of Australian women

The relation between multiple social roles and health is a particular issue for women, who continue to take major responsibility for childcare and domestic labor despite increasing levels of involvement in the paid workforce. This article analyzes Survey 1 data from the Australian Longitudinal Survey on Women’s Health to explore relations between role occupancy and health, well-being, and health service use in three generations of Australian women. A total of 41,818 women in three age groups (young, 18-23; mid-age, 40-45; older, 70-75) responded to mailed surveys. Young and mid-age women were classified according to their occupancy of five roles—paid worker, partner, mother, student, and family caregiver—whereas older women were classified according to occupancy of partner and caregiver roles only. Common symptoms (headaches, tiredness, back pain, difficulty sleeping), diagnosis of chronic illness, and use of health services were compared across groups characterized by number of roles. Comparisons were also conducted on the physical and mental component scores of the SF-36 and perceived stress, with and without adjustment for confounders. Among young women, the best health was associated with occupancy of one role; among mid-age women, those with three or more roles were in the best health; and for older women, those with one role were in the best health. Young women with noneorwith fourormore roles, and mid-age and older women with none of the defined social roles tended to be in the poorest health. Different patterns of results may be explained by differences in the extent to which women at different life stages feel committed to various social roles, and to the extent to which they are able to draw on social, material, and economic supports.

Screening for Vulnerability to Abuse Among Older Women: Women's Health Australia Study

The validity of a brief self-report screening measure for elder abuse was examined on a nationally representative sample of more than 12,000 older women in the baseline survey of the Australian Longitudinal Study onWomens Health. The screening instrument was a modification of the Hwalek-Sengstock Elder Abuse Screening Test. Construct validity was examined using factor analysis and correlation with a wide range of sociodemographic, psychological, and healthrelated variables. Four factors, each of three items, were identified representing the following domains: Vulnerability, Dependence, Dejection, and Coercion. The Vulnerability and Coercion factors had the highest face validity for abuse and demonstrated moderate to good construct validity. The six items comprising these factors may provide a simple screening tool for elder abuse. The identified correlates of abuse indicators have the potential to enhance policy development, screening, intervention, and carer support programs.

Mortality and Disability Outcomes of Self‐Reported Elder Abuse: A 12‐Year Prospective Investigation

To determine whether elder abuse can predict mortality and disability over the ensuing 12 years.

Longitudinal analysis of alcohol consumption and health of middle‐aged women in Australia

AIMS To assess the prospective association between alcohol consumption and self-rated health: in particular whether there is a relationship between stable alcohol intake and health; whether health is affected by changes in alcohol consumption; whether having a chronic condition alters the relationships between stable and changing alcohol intake and health; and whether the health of longer-term abstainers is different from more recent and intermittent abstainers. DESIGN Longitudinal analysis of a prospective, population-based study. SETTING Australia. PARTICIPANTS A total of 13 585 randomly selected 45-50-year-old women surveyed in 1996, of whom 9396 (69%) were resurveyed in 1998, 2001 and 2004. MEASUREMENTS Estimates for the General Health subscale of the SF-36 for different levels of alcohol intake adjusted for having a chronic condition, depression, smoking and other factors. FINDINGS Longitudinal models of consistent alcohol intake showed mean scores for general health of moderate drinkers were significantly better than that of non-drinkers [mean difference = 4.3, standard error (SE) = 0.61], occasional drinkers (mean difference = 3.1, SE = 0.52) and heavy drinkers (mean difference = 2.1, SE = 1.00). Among moderate drinkers, a decrease or variation in alcohol consumption was associated with a significant decline of three to four points in general health. Similar results were obtained when women with an existing chronic condition were excluded from these models. The health of recent abstainers and intermittent drinkers was the same as longer-term abstainers. CONCLUSIONS Consistent moderate drinkers had the best health even after adjustment for having a chronic condition, depression and life-style factors. Poorer health was associated with decreased alcohol intake among occasional and moderate drinkers.

Recruitment via the Internet and social networking sites: the 1989-1995 cohort of the Australian Longitudinal Study on Women's Health.

Background Faced with the challenge of recruiting young adults for health studies, researchers have increasingly turned to the Internet and social networking sites, such as Facebook, as part of their recruitment strategy. As yet, few large-scale studies are available that report on the characteristics and representativeness of the sample obtained from such recruitment methods. Objective The intent of the study was to describe the sociodemographic and health characteristics of a national sample of young Australian women recruited mainly through the Internet and social networking sites and to discuss the representativeness of their sociodemographic, health, and lifestyle characteristics relative to the population. Methods A cohort of 17,069 women (born between 1989 and 1995) was recruited in 2012-13 for the Australian Longitudinal Study on Women’s Health. Sociodemographic characteristics (percentages, means, and 95% confidence intervals) from the online survey data were compared with women aged 18-23 years from the 2011 Australian Census. Sample data were compared by age and education level with data from the 2011-13 Australian Health Survey (AHS). Results Compared to the Australian Census data, study participants were broadly representative in terms of geographical distribution across Australia, marital status (95.62%, 16,321/17,069) were never married), and age distribution. A higher percentage had attained university (22.52%, 3844/17,069) and trade/certificate/diploma qualifications (25.94%, 4428/17,069) compared with this age group of women in the national population (9.4% and 21.7% respectively). Among study participants, 22.05% (3721/16,877) were not in paid employment with 35.18% (5931/16,857) studying 16 or more hours a week. A higher percentage of study participants rated their health in the online survey as fair or poor (rather than good, very good, or excellent) compared with those participating in face-to-face interviews in the AHS (18.77%, 3203/17,069 vs 10.1%). A higher percentage of study participants were current smokers (21.78%, 3718/17,069 vs 16.4%) and physically active (59.30%, 10,089/17,014 were classified as sufficiently active vs 48.3%) but alcohol consumption was lower (59.58%, 9865/16,558 reported drinking alcohol at least once per month vs 65.9% in the AHS). Using self-reported height and weight to determine body mass index (BMI, kg/m2), 34.80% (5901/16,956) of the cohort were classified as overweight or obese (BMI of 25 or more), compared with 33.6% respectively using measured height and weight in the AHS. Conclusions Findings indicated that using the Internet and social networking sites for an online survey represent a feasible recruitment strategy for a national cohort of young women and result in a broadly representative sample of the Australian population.