Frailty state utility and minimally important difference: findings from the North West Adelaide Health Study.

BACKGROUND: frailty is a dynamic condition for which a range of interventions are available. Health state utilities are values that represent the strength of an individual's preference for specific health states, and are used in economic evaluation. This is a topic yet to be examined in detail for frailty. Likewise, little has been reported on minimally important difference (MID), the extent of change in frailty status that individuals consider to be important. OBJECTIVES: to examine the relationship between frailty status, for both the frailty phenotype (FP) and frailty index (FI), and utility (preference-based health state), and to determine a MID for both frailty measures. DESIGN AND SETTING: population-based cohort of community-dwelling Australians. PARTICIPANT: in total, 874 adults aged ≥65 years (54% female), mean age 74.4 (6.2) years. MEASUREMENTS: frailty was measured using the FP and FI. Utilities were calculated using the short-form 6D health survey, with Australian and UK weighting applied. MID was calculated cross-sectionally. RESULTS: for both the FP and FI, frailty was significantly statistically associated (P < 0.001) with lower utility in an adjusted analysis using both Australian and UK weighting. Between-person MID for the FP was identified as 0.59 [standard deviation (SD) 0.31] (anchor-based) and 0.59 (distribution-based), whereas for the FI, MID was 0.11 (SD 0.05) (anchor-based) and 0.07 (distribution-based). CONCLUSIONS: frailty is significantly associated with lower preference-based health state utility. Frailty MID can be used to inform design of clinical trials and economic evaluations, as well as providing useful clinical information on frailty differences that patients consider important.

Assessing Heavy Episodic Drinking: A Random Survey of 18 to 34-Year-Olds in Four Cities in Four Different Continents.

BACKGROUND: Heavy episodic drinking (HED) can have health and social consequences. This study assesses the associations between HED and demographic, socioeconomic, motivation and effects indicators for people aged 18⁻34 years old living in four cities in different regions of the world. METHOD: Multistage random sampling was consistent across the four cities (Ilorin (Nigeria), Wuhan (China), Montevideo (Uruguay) and Moscow (Russia)). The questionnaire was forward/back translated and face-to-face interviewing was undertaken. A total of 6235 interviews were undertaken in 2014. Separate univariable and multivariable modelling was undertaken to determine the best predictors of HED. RESULTS: HED prevalence was 9.0%. The best predictors differed for each city. The higher probability of HED in the final models included beliefs that they have reached adulthood, feeling relaxed as an effect of drinking alcohol, and forgetting problems as an effect of drinking alcohol. Lower probability of HED was associated with not being interested in alcohol as a reason for limiting alcohol, and the belief that drinking alcohol is too expensive or a waste of money. CONCLUSION: Although some indicators were common across the four cities, the variables included in the final models predominantly differed from city to city. The need for country-specific prevention and early intervention programs are warranted.

Validating the Short Form-12 and the development of disease-specific norms in a cohort of Australian private health insurance members.

Despite the large number of Australians with private health insurance (PHI), normative quality-of-life data are not available for this population. The Short Form (SF)-12 has been used to characterise the health-related quality of life of Australians in the general population, but there is debate concerning the appropriate algorithm that should be used to calculate its physical and mental component summary scores. The standard (orthogonal method) approach assumes that the mental and physical components are unrelated, whereas an alternate approach (the correlated method) assumes that the two components are related. A consecutive sample of 24957 PHI members with four major initial disease conditions were administered the SF-12 via phone and 4330 participants were followed up at a mean of 16 months after the first survey. The SF-12 was scored using both the orthogonal and correlated methods, and both scoring models were assessed for model fit and ability to discriminate between the four major disease conditions. Confirmatory factor analysis demonstrated superior model fit and improved discriminative validity when the SF-12 was scored using the correlated method instead of the default orthogonal method. Further, the correlated method demonstrated utility by producing scores that were responsive to change over time.

The case for using country-specific scoring coefficients for scoring the SF-12, with scoring implications for the SF-36.

PURPOSE: To examine the validity of using the same scoring coefficients across countries for the SF-12. METHODS: We test the equality of scoring coefficients derived for a contraction of the SF-36, the Short Form 12 (SF-12), using a large international database drawn from nine countries, to test equality between Australia and twelve other country/language groups. First, we checked that the theoretical structure of the SF-12 as set out by Ware and colleagues, but including a correlation between physical and mental health, provided an adequate fit to the data for each country/language group in a confirmatory factor analysis. We then compared Australia to all of these country/language groups in multiple-group models to assess whether a model producing common factor score coefficients provided an adequate fit to the data. We also derived Chi-squared tests for the differences between the restricted and unrestricted models, to test the equality of the factor score coefficients across countries. RESULTS: We found that the theoretical structure of the SF-12, with a correlation between physical and mental health, provides an adequate fit to the data for all country/language groups except Hungary. Further, all the unrestricted multiple-group models provide an adequate fit to the data. In contrast, none of the multiple-group models restricted to common parameters provide an adequate fit to the data. The significance tests confirm that the constraints on parameter values produce significantly different models to the unrestricted models. CONCLUSIONS: We conclude that researchers should derive their own country-specific scoring coefficients for physical and mental health summary scores.

Health Estimates Using Survey Raked-Weighting Techniques in an Australian Population Health Surveillance System.

A challenge for population health surveillance systems using telephone methodologies is to maintain representative estimates as response rates decrease. Raked weighting, rather than conventional poststratification methodologies, has been developed to improve representativeness of estimates produced from telephone-based surveillance systems by incorporating a wider range of sociodemographic variables using an iterative proportional fitting process. This study examines this alternative weighting methodology with the monthly South Australian population health surveillance system report of randomly selected people of all ages in 2013 (n = 7,193) using computer-assisted telephone interviewing. Poststratification weighting used age groups, sex, and area of residence. Raked weights included an additional 6 variables: dwelling status, number of people in household, country of birth, marital status, educational level, and highest employment status. Most prevalence estimates (e.g., diabetes and asthma) did not change when raked weights were applied. Estimates that changed by at least 2 percentage points (e.g., tobacco smoking and mental health conditions) were associated with socioeconomic circumstances, such as dwelling status, which were included in the raked-weighting methodology. Raking methodology has overcome, to some extent, nonresponse bias associated with the sampling methodology by incorporating lower socioeconomic groups and those who are routinely not participating in population surveys into the weighting formula.

Heat-health behaviours of older people in two Australian states.

AIM: A major heatwave occurred in Australia in early 2009 with considerable and varied health impacts in South Australia (SA) and Victoria. The aim of this study was to investigate the heat-adaptive behaviours of older people in these states. METHODS: A computer-assisted telephone survey of 1000 residents of SA and Victoria aged 65 years or older was conducted at the end of summer 2010-2011. RESULTS: The majority of respondents reported undertaking heat-adaptive behaviours. In SA, there was a significantly higher proportion of households with air conditioning compared to Victoria, and a higher recall of heat-health messages. In both states, self-reported morbidity during heatwaves was higher in women, persons with poorer health and those with cardiovascular conditions. CONCLUSION: An increase in global temperatures in conjunction with an ageing population is a concern for public health. Our findings suggest acclimatisation to hot weather may influence behaviours and health outcomes in older people.

Results from several population studies show that recommended scoring methods of the SF-36 and the SF-12 may lead to incorrect conclusions and subsequent health decisions.

PURPOSE: To compare the measurement properties of the physical component summary (PCS) and mental component summary (MCS) scores of the SF-36 and SF-12 based on the traditional orthogonal scoring algorithms with the performance of the PCS and MCS scored based on structural equation model coefficients from a correlated model. METHODS: This study used three large-scale representative population studies to compare the measurement properties of the PCS and MCS scores of the SF-36 and SF-12 with the performance of the PCS and MCS scores based on structural equation models producing coefficients from a correlated model. We assessed the relationships of these scores with selected important mental health measures and chronic conditions from three representative Australian population studies that address clinical conditions of high prevalence and health service importance. RESULTS: Structural equation model scoring methods produced summary scores with higher correlations than the recommended orthogonal methods across a range of disease and health conditions. The problem experienced in using the orthogonal methods is that negative scoring coefficients are applied to negative z-scores for sub-scales, inflating the resulting summary scores. Effect sizes over a half of a standard deviation were common. CONCLUSIONS: If health policy or investment decisions are made based on the results of studies employing the recommended orthogonal scoring methods then the expected outcome of such decisions or investments may not be achieved.

Functional health literacy mediates the relationship between socio-economic status, perceptions and lifestyle behaviors related to cancer risk in an Australian population.

OBJECTIVE: To determine if functional health literacy (FHL) mediates the relationship between socio-economic status, and perception of the risk of lifestyle behaviors for cancer. METHODS: Cross-sectional, random population survey, 2824 people aged ≥15 years, September-October 2008, included newest vital sign measure of FHL. RESULTS: Less than adequate FHL occurred in 45.1%. People who perceived behavioral factors (smoking, diet, obesity, alcohol, physical activity) to be not important, or did not know if they were important cancer risks, were more likely to have inadequate FHL. In a logistic regression model adjusted for age, gender, education, income, occupation, country of birth and area of residence, inadequate FHL was associated with 2-3 (OR=1.9; 95% CI: 1.2-3.0) and 4 or more self-reported lifestyle risk factors (OR=2.8; 95% CI: 1.6-5.0). In a structural equation model of the relationship of socio-economic status, perceptions of risk and behaviors there was significant mediation effect of FHL on the path from SES to health perceptions, estimated 29.4% of the total effect. CONCLUSION: A specific focus on the literacy demands made on individuals from health promotion and materials with a view to improving health communication is indicated. PRACTICE IMPLICATIONS: Health literacy is important for health promotion.

Is narrow band imaging superior to high-definition white light endoscopy in the assessment of diminutive colorectal polyps?

BACKGROUND AND AIM: Diminutive polyps measuring ≤ 5 mm in size constitute 80% of polyps in the colon. We prospectively assessed the performance of high-definition white light endoscopy (hWLE) and narrow band imaging (NBI) in differentiating diminutive colorectal polyps. METHODS: In this prospective, multicenter study, videos of 50 diminutive polyps (31 hyperplastic, 19 adenomatous) in hWLE followed by NBI (total 100 videos) were initially obtained and placed in random order into five separate folders (each folder 20 videos). Eight endoscopists were then invited to predict the histology (each endoscopist 100 videos, 800 video assessments in all). Polyps were classified into types 1-3 (hyperplastic) and type 4 (adenoma). Feedback on individual performance was given after each folder (20 videos) was assessed. RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in differentiating hyperplastic from adenomatous polyps by hWLE (400 videos) and NBI (400 videos) were 67.8%, 90.7%, 81.7%, 82.1%, and 82.0%; and 82.2%, 81.5%, 73.1%, 88.2%, and 81.8%, respectively. In the pretest and post-test analysis, the accuracy with NBI improved markedly from 68.8% to 91.3% (P = 0.001) compared with hWLE, 76.3-78.8% (P = 0.850). Overall, the interobserver agreement was 0.46 for hWLE (moderate) and 0.64 for NBI (good). CONCLUSIONS: NBI was as accurate as hWLE in differentiating diminutive colorectal polyps. Once a learning curve was reached, NBI achieved significantly higher accuracies with good interobserver agreement. Using a simplified classification, a didactic learning session and feedback on performance, diminutive colorectal polyps could be predicted with high accuracies with NBI.

Relationship of social factors including trust, control over life decisions, problems with transport and safety, to psychological distress in the community.

PURPOSE: Psychological distress encompasses anxiety and depression with the previous studies showing that psychological distress is unequally distributed across population groups. This paper explores the mechanisms and processes which may affect the distribution of psychological distress, including a range of individual and community level socioeconomic determinants. METHODS: Representative cross-sectional data was collected for respondents aged 16+ from July 2008 to June 2009, as a part of the South Australian Monitoring and Surveillance System (SAMSS) using Computer Assisted Telephone Interviews (CATI). Univariate and multivariate analyses (n = 5,763) were conducted to investigate the variables that were associated with psychological distress. RESULTS: The overall prevalence of psychological distress was 8.9%. In the multivariate model, females, those aged 16-49, respondents single with children, unable to work or unemployed, with a poorer family financial situation, earning $20,000 or less, feeling safe in their home some or none of the time, feeling as though they have less then total control over life decisions and sometimes experiencing problems with transport, were significantly more likely to experience psychological distress. CONCLUSIONS: This paper has demonstrated the relationship between low-income, financial pressure, less than optimal safety and control, and high-psychological distress. It is important that the groups highlighted as vulnerable be targeted in policy, planning, and health promotion and prevention campaigns.

Heat and health in Adelaide, South Australia: assessment of heat thresholds and temperature relationships.

BACKGROUND: Climate change projections have highlighted the need for public health planning for extreme heat. In Adelaide, South Australia, hot weather is characteristic of summer and heatwaves can have a significant health burden. This study examines the heat thresholds and temperature relationships for mortality and morbidity outcomes in Adelaide. METHODS: Daily maximum and minimum temperatures, daily mortality, ambulance call-outs, emergency department (ED) presentations and hospital admissions were obtained for Adelaide, between 1993 and 2009. Heat thresholds for health outcomes were estimated using an observed/expected analysis. Generalized estimating equations were used to estimate the percentage increase in mortality and morbidity outcomes above the threshold temperatures, with adjustment for the effects of ozone (O(3)) and particulate matter<10 µm in mass median aerodynamic diameter (PM(10)). Effect estimates are reported as incidence rate ratios (IRRs). RESULTS: Heat-related mortality and morbidity become apparent above maximum and minimum temperature thresholds of 30 °C and 16 °C for mortality; 26 °C and 18 °C for ambulance call-outs; and 34 °C and 22 °C for heat-related ED presentations. Most health outcomes showed a positive relationship with daily temperatures over thresholds. When adjusted for air pollutants, a 10 °C increase in maximum temperature was associated with a 4.9% increase in daily ambulance call-outs (IRR 1.049; 95% CI 1.027-1.072), and a 3.4% increase in mental health related hospital admissions (IRR 1.034; 95% CI 1.009-1.059) for the all-age population. Heat-related ED presentations increased over 6-fold per 10 °C increase in maximum temperature. Daily temperatures were also associated with all-cause and mental health related ED presentations. Associations between temperature over thresholds and daily mortality and renal hospital admissions were not significant when adjusted for ozone and PM(10); however at extreme temperatures mortality increased significantly with increasing heat duration. CONCLUSIONS: Heat-attributable mortality and morbidity are associated with elevated summer temperatures in Adelaide, particularly ambulance call-outs, mental health and heat-related illness.

Extreme heat arrangements in South Australia: an assessment of trigger temperatures.

ISSUE ADDRESSED: The high mortality and morbidity associated with the 2009 heat wave across South Eastern Australia highlighted the need for effective heat-related health promotion and preventive strategies. The adverse health effects of extreme heat are largely preventable, and heat-related health promotion can advise the public about the dangers of hot weather and how to reduce health risks. The South Australian State Emergency Service has outlined a co-ordinated response system in their Extreme Heat Arrangements for South Australia. This paper evaluates the health impacts at the temperature trigger levels incorporated in this plan. METHODS: Heat events in Adelaide between 1994 and 2009 were compared in terms of heat duration, heat intensity and their impact on mortality and ambulance call-outs.The health impacts for events meeting specific temperature triggers were estimated. RESULTS: Individual heat events varied in terms of estimated excess mortality and ambulance call-outs. Increased mortality was associated with heat events of 3 or more consecutive days with maximum temperature (T(max)) > or = 43 degrees C or average daily temperature (ADT) > or = 34 degrees C, while ambulance call-outs increased significantly at lower T(max) levels.The two events reaching the temperature triggers for an extreme heat warning were associated with a 44% (95% CI 26-63%) increase in mortality. CONCLUSIONS: The results support the temperature trigger for an extreme heat warning within the Extreme Heat Arrangements for Adelaide, and indicate a limited health impact at lower temperature triggers.

Effects of area deprivation on health risks and outcomes: a multilevel, cross-sectional, Australian population study.

OBJECTIVES: Our aim was to examine the effect of local area socio-economic disadvantage after accounting for individual socio-economic status (SES), and to determine if these differ between various health and risk factor variables. METHODS: The North West Adelaide Health Study (NWAHS) is a biomedical representative population study of adults. The Index of Relative Socio-Economic Disadvantage (IRSD), produced from the Australian Bureau of Statistics (ABS) Census data at the level of Collector Districts (200 dwellings) was used as an indicator of local area disadvantage. Multi-level modeling techniques examined the effects of IRSD level on a variety of health outcomes and risk factors, after accounting for individual socio-economic factors. RESULTS: Significant, independent associations were seen between IRSD and obesity, smoking, and health-related quality of life, with 5 % to 7.2 % of the variance located at the neighborhood level. No independent associations were seen between IRSD and estimated cardiovascular disease risk, diabetes, physical activity, or at-risk alcohol use. CONCLUSIONS: Aggregated area-level characteristics make modest, but significant independent contributions to smoking, obesity and quality of life, but not for other health outcomes.