The use of a chronic disease and risk factor surveillance system to determine the age, period and cohort effects on the prevalence of obesity and diabetes in South Australian adults--2003-2013

Body mass index and waist circumference trajectories across the life course and birth cohorts, 1996-2015 Malaysia: sex and ethnicity matter

OBJECTIVE

The global obesity epidemic remains a significant threat to public health and the economy. Age-period-cohort (APC) analysis is one method to model the trajectory of obesity. However, there is scarce published evidence of such analyses among the South East Asian population. This study aims to explore the sex and ethnic variations of BMI and waist circumference trajectories over time among non-institutionalized Malaysian adults aged 18 to 80 years.

METHODS

Data from four population-based National Health and Morbidity Surveys conducted in 1996, 2006, 2010, and 2015 were pooled. Hierarchical Age-Period-Cohort (HAPC) analysis explored the trajectories of BMI and waist circumference across the life course and birth cohorts by sex and ethnicity. These models assumed no period effect.

RESULTS

Generally, BMI and waist circumference trajectories increased across age and birth cohorts. These trajectories varied by sex and ethnicity. Females have more profound increasing BMI and waist circumference trajectories than their male counterparts as they age and as cohort recency increases. Chinese have less profound BMI and waist circumference increases across the life course and birth cohorts than other ethnic groups.

CONCLUSIONS

The profound increasing cohort trajectories of obesity, regardless of sex and ethnicity, are alarming. Future studies should focus on identifying factors associated with the less profound cohort effect among the Chinese to reduce the magnitude of trajectories in obesity, particularly among future generations.

Age and cohort rise in diabetes prevalence among older Australian women: Case ascertainment using survey and healthcare administrative data

BACKGROUND

Due to the absence and or costliness of biological measures such as glycated haemoglobin, diabetes case ascertainment and prevalence studies are usually conducted using surveys or routine health service use databases. However, the use of each of these sources is associated with its limitations potentially impacting the quality of the case ascertainment and prevalence estimation. This study aimed at ascertaining diabetes cases and estimating prevalence among mid- and older-age women through simultaneous use of a longitudinal survey and multiple healthcare administrative data sources.

METHODS

Data were available for 12,432 and 13,714 women born in 1921-26 and 1946-51 from the Australian Longitudinal Study on Women's Health (ALSWH). Diabetes was ascertained using the ALSWH survey, health service use, and cause of death data. Parsimonious multiple logistic regression analyses tested associations between sociodemographic and health variables and the presence of diabetes.

RESULTS

In both cohorts, two or more of the sources captured more than 80% of the women with diabetes. The point prevalence of diabetes increased from 8.4% when the mean age of the women were aged 73, to 22.0% of surviving women at age 90 in the 1921-26 cohort; and from 2.6% at age 48 to 15.8% at age 68 in the 1946-51 cohort. In the 1921-26 cohort, women who were obese (OR: 3.56; 95 CI: 3.04-4.17) and women who were sedentary (OR: 1.18; 95 CI: 1.09-1.40) were more likely to have diabetes compared to those who had a normal weight and engaged in a moderate level of physical activity. In the 1946-51 cohort, the odds of diabetes increased three times (OR: 2.99; 95 CI: 2.54-3.52) for overweight women and nine times (OR: 8.78; 95 CI: 7.46-10.33) for obese women compared to those who had normal weight.

CONCLUSIONS

The simultaneous use of multiple data sources improved the validity of diabetes case ascertainment. Application of this methodology in future studies may have important benefits including estimation of disease burden, health service needs, and resource allocation with improved precision. Diabetes prevalence increased with age, was much higher in the 1946-51 cohort than in 1921-26 at similar ages, and was significantly associated with physical inactivity and obesity. Interventions to promote physical activity and a healthy weight are needed to prevent the rising prevalence of diabetes across successive generations.

Changes in the prevalence of comorbidity in the Australian population with cancer, 2007-2014

BACKGROUND

Coexistence of multiple chronic diseases is highly prevalent among the cancer population. This study aims to assess changes in the prevalence of chronic conditions among the population with cancer compared to the Australian general population between 2007 and 2014.

METHODS

Data from three successive National Health Surveys conducted by the Australian Bureau of Statistics between 2007 and 2014 were utilized. Comparisons were made between the samples of the Australian population aged 25 years and above with a history of cancer and those respondents who did not report having had a cancer using logistics regression models.

RESULTS

People with a history of cancer had significantly higher odds of reporting non-infectious comorbidity compared to the non-cancer groups across the three surveys. There were no significant changes in the prevalence of diseases affecting circulatory, musculoskeletal, digestive, nervous system, blood and blood forming organs, eye, skin and infectious and parasitic diseases over time among the population with cancer. The prevalence of mental and behavioural problems, endocrine, nutritional and metabolic diseases, and diseases of respiratory and genitourinary system has increased over time among the cancer survivors.

CONCLUSION

Comorbidity is more prevalent among the cancer population than the general population without cancer. The prevalence of comorbidity was fairly stable for most but not all comorbidities in the population with cancer over the eight-year study period. Further studies on the impacts of coordinated care models for the management of multi-morbidity experienced by cancer survivors that align with the 'National Strategic Framework for Chronic Conditions' are needed.

Comparison of Health and Risk Factors of Older, Working-age Australians, Italians and Italian-born Migrants to Australia, with Data from an Italian (PASSI), and an Australian (SAMSS) Risk Factor Surveillance System

Italian-born migrants (post-WWII) are the largest non-English-speaking background migrant group in South Australia. A cross-sectional, inter-country comparison using independent samples (40–69 years of age) from two (one in Australia, one in Italy) similar risk factor and chronic disease surveillance systems. None of the three groups (Italians, Australian-born and Italian-born Australians) had definitively worse health although the Italians had high rates for four of the seven risk factors reported (current high blood pressure, current high cholesterol, current smoking, eating less than five fruit and/or vegetables per day) than Australian-born and Italian-born Australians. Italian-born Australians had higher rates for insufficient physical activity, overweight/obese, poor self-reported health and diabetes. Australian respondents were more likely to report having two or more drinks of alcohol per day. Issues facing an ageing population require appropriate health care needs and an assessment of structural or cultural barriers to health services.

The Contribution of Ageing to Hospitalisation Days in Hong Kong: A Decomposition Analysis

Background: Ageing has become a serious challenge in Hong Kong and globally. It has serious implications for health expenditure, which accounts for nearly 20% of overall government expenditure. Here we assess the contribution of ageing and related factors to hospitalisation days in Hong Kong. We used hospital discharge data from all publicly funded hospitals in Hong Kong between 2001 and 2012.

Methods: A decomposition method was used to examine the factors that account for the change of total hospitalisation days during the two periods, 2001-2004 and 2004-2012. The five factors include two demographic factors – population size and age-gender composition – and three service components – hospital discharge rate, number of discharge episodes per patient, and average length of stay (LOS) – which are all measured at age-gender group level. In order to assess the health cost burden in the future, we also project the total hospitalisation days up to 2041, for a range of scenarios.

Results: During the decreasing period of hospitalisation days (2001-2004), the reduction of LOS contributed to about 60% of the reduction. For the period of increase (2004-2012), ageing is associated with an increase in total hospitalisation days of 1.03 million, followed by an increase in hospital discharge rates (0.67 million), an increase in the number of discharge episodes per patient (0.62 million), and population growth (0.43 million). The reduction of LOS has greatly offset these increases (-2.19 million days), and has become one of the most significant factors in containing the increasing number of hospitalisation days. Projected increases in total hospitalisation days under different scenarios have highlighted that the contribution of ageing will become even more prominent after 2022.

Conclusion: Hong Kong is facing increasing healthcare burden caused by the rapid increase in demand for inpatient services due to ageing. Better management of inpatient services with the aim of increasing efficiency and reducing LOS, avoidable hospitalisation and readmission, without compromising patient satisfaction and quality of service, are crucial for containing the rapid and enormous increases in total hospitalisation days for Hong Kong. The results would be relevant to many rapidly ageing societies in this region.

Unpaid Informal Caregivers in South Australia: Population Characteristics, Prevalence and Age-Period-Cohort Effects 1994-2014

BACKGROUND

The ongoing need for an availability of informal carers is taking on greater relevance as the global burden of disease transitions from acute fatal diseases to long term morbidity. Growing evidence suggests that extra burden on family carers may further impact on their health and ability to provide care. Important as it is to monitor the prevalence of those conditions which influence the burden of disease, it is also important to monitor the prevalence and health profiles of those who provide the informal care. The aim of this study was to demonstrate the prevalence and demographics of adult carers aged 15 and over in the state of South Australia over 20 years between 1994 and 2014.

METHODS

Data from nine representative, cross-sectional population surveys, conducted in South Australia, Australia were used, (total N = 26,788 and n = 1,504 carers). The adjusted prevalence estimate of carers and their demographic characteristics were determined. So as to examine whether there were any generational effects on the prevalence of carers, an Age-Period Cohort (APC) analysis was undertaken.

RESULTS

The prevalence estimates of carers increased during the two decades from 3.7% in 1994 to 6.7% by 2014. Large increases in the proportion of retired carers, those aged 70 years and over, those carers employed, and those with higher educational qualifications were observed. There were also larger proportions of respondents with a country of birth other than Australia, UK, Ireland and European counties. The APC analysis illustrated an increasing prevalence rate over each decade for carers aged 20-80 years, especially for those over the age of 60 years.

CONCLUSIONS

The results illustrate changing carer characteristics and carer prevalence estimates in South Australia as new generations of carers take on the caring role. There is a need to include questions regarding informal carers within ongoing mainstream population surveys, particularly at state levels, so as to plan for their future health care and home support.

Normal-Weight Central Obesity and Mortality Risk in Older Adults With Coronary Artery Disease

OBJECTIVE

To study the relationship between body mass index (BMI) and central obesity and mortality in elderly patients with coronary artery disease (CAD).

PATIENTS AND METHODS

We identified 7057 patients 65 years or older from 5 cohort studies assessing mortality risk using either waist circumference (WC) or waist-hip ratio (WHR) in patients with CAD from January 1, 1980, to December 31, 2008. Normal weight, overweight, and obesity were defined using standard BMI cutoffs. High WHR was defined as 0.85 or more for women and 0.90 or more for men. High WC was defined as 88 cm or more for women and 102 cm or more for men. Separate models examined WC or WHR in combination with BMI (6 categories each) as the primary predictor (referent = normal BMI and normal WC or WHR). Cox proportional hazards models investigated the relationship between these obesity categories and mortality.

RESULTS

Patients' mean age was 73.0±6.0 years (3741 [53%] women). The median censor time was 7.1 years. A normal BMI with central obesity (high WHR or high WC) demonstrated highest mortality risk (hazard ratio [HR], 1.29; 95% CI, 1.14-1.46; HR, 1.29; 95% CI, 1.12-1.50, respectively). High WHR was also predictive of mortality in the overall (HR, 2.14; 95% CI, 1.93-2.38) as well as in the sex-specific cohort. In the overall cohort, high WC was not predictive of mortality (HR, 1.04; 95% CI, 0.97-1.12); however, it predicted higher risk in men (HR, 1.12; 95% CI, 1.01-1.24).

CONCLUSION

In older adults with CAD, normal-weight central obesity defined using either WHR or WC is associated with high mortality risk, highlighting a need to combine measures in adiposity-related risk assessment.