The gaits of marsupials and the evolution of diagonal-sequence walking in primates.

OBJECTIVES: Documenting the variety of quadrupedal walking gaits in a variety of marsupials (arboreal vs. terrestrial, with and without grasping hind feet), to aid in developing and refining a general theory of gait evolution in primates. MATERIALS AND METHODS: Video records of koalas, ringtail possums, tree kangaroos, sugar gliders, squirrel gliders, wombats, numbats, quolls, a thylacine, and an opossum walking on a variety of substrates were made and analyzed to derive duty factors and diagonalities for symmetrical walking gaits. The resulting distributions of data points were compared with published data and theories. RESULTS: Terrestrial marsupials' gaits overwhelmingly plot slightly below the theoretical "horse line" (Cartmill et al., Zoological Journal of the Linnean Society. 2002;136:401-420) typical of terrestrial mammals; arboreal marsupials' gaits overwhelmingly plot more decisively above it. Both distributions are roughly parallel to the horse line, but arboreal animals exhibit increased diagonality, so that their higher-speed walking gaits overlap with those of typical primates on the Hildebrand diagram of diagonality against duty factor. CONCLUSIONS: Quadrupeds avoid gaits lying exactly on the (theoretically optimum) horse line, to avoid fore/hind limb interference ("forging"). This can be accomplished by either a slight reduction in diagonality ("downshifting") or a more decisive increase ("upshifting"). Tree-dwellers adopt the second option to eliminate unilateral bipods of support from the gait cycle. The upshifted horse line represents an early phase in the evolution of primate-like diagonal-sequence gaits.

Association of epilepsy and burns - a case control study.

BACKGROUND: General practitioners play a vital role in reducing risk for people with epilepsy through pharmacological prevention of seizures. Burns are the most common injury sustained during epileptic seizure. This article examines the risk of burns among patients with epilepsy in Victoria. METHODS: A case control study was conducted using the Victorian Admitted Episodes Dataset (VAED) from 2000-2005. Odds ratios were adjusted for potential confounders and 95% confidence intervals were calculated comparing burns among epilepsy versus nonepilepsy patients using multivariate logistic regression. RESULTS: Epilepsy was three times more likely to be associated with burns, with women being five times more likely to be burned. Hot drinks, food, fats, cooking oils, steam and household appliances, hot tap water, hot fluids other than water, and hot heating appliances were all significant causes. The strength of association between epilepsy and burns for these types of causes was consistently higher for women compared with men. DISCUSSION: This study has shown a strong association between epilepsy and burns in hospital admissions, and identifies the importance of using routine databases for contributing to the limited knowledge about seizure related burns in epileptic patients.

A six-year descriptive analysis of hospitalisations for ambulatory care sensitive conditions among people born in refugee-source countries.

BACKGROUND: Hospitalisation for ambulatory care sensitive conditions (ACSHs) has become a recognised tool to measure access to primary care. Timely and effective outpatient care is highly relevant to refugee populations given the past exposure to torture and trauma, and poor access to adequate health care in their countries of origin and during flight. Little is known about ACSHs among resettled refugee populations. With the aim of examining the hypothesis that people from refugee backgrounds have higher ACSHs than people born in the country of hospitalisation, this study analysed a six-year state-wide hospital discharge dataset to estimate ACSH rates for residents born in refugee-source countries and compared them with the Australia-born population. METHODS: Hospital discharge data between 1 July 1998 and 30 June 2004 from the Victorian Admitted Episodes Dataset were used to assess ACSH rates among residents born in eight refugee-source countries, and compare them with the Australia-born average. Rate ratios and 95% confidence levels were used to illustrate these comparisons. Four categories of ambulatory care sensitive conditions were measured: total, acute, chronic and vaccine-preventable. Country of birth was used as a proxy indicator of refugee status. RESULTS: When compared with the Australia-born population, hospitalisations for total and acute ambulatory care sensitive conditions were lower among refugee-born persons over the six-year period. Chronic and vaccine-preventable ACSHs were largely similar between the two population groups. CONCLUSION: Contrary to our hypothesis, preventable hospitalisation rates among people born in refugee-source countries were no higher than Australia-born population averages. More research is needed to elucidate whether low rates of preventable hospitalisation indicate better health status, appropriate health habits, timely and effective care-seeking behaviour and outpatient care, or overall low levels of health care-seeking due to other more pressing needs during the initial period of resettlement. It is important to unpack dimensions of health status and health care access in refugee populations through ad-hoc surveys as the refugee population is not a homogenous group despite sharing a common experience of forced displacement and violence-related trauma.

Avoidable mortality in Victoria between 1979 and 2001.

OBJECTIVE: To describe trends in avoidable mortality (AM) in Victoria by sex, degree of socio-economic disadvantage and remoteness. METHODS: The analysis is based on mortality and population data for 1979-2001 supplied by the Australian Bureau of Statistics (ABS) for Victoria. Total and disease-specific AM rates were age standardised using the direct method. For the period between 1997 and 2001, comparisons of total AM rates by sex were made between metropolitan and rural local government areas (LGAs), and between LGAs grouped into quintiles based on socio-economic disadvantage and categories of remoteness. RESULTS: Total AM rates declined significantly (p < 0.05) in both males and females between 1979 and 2001, but were significantly higher in males compared with females. Total AM rates were significantly higher in rural compared with metropolitan LGAs, from 1997 to 2001 in males and in 1998 in females. Total AM rates in the least disadvantaged quintile were significantly lower than those in the most disadvantaged quintile over the entire five-year period in males and in three years in females. Total AM rates were highest in remote LGAs and lowest in highly accessible LGAs. There were significant declines in ischaemic heart disease, stroke and road traffic accident AM rates among males. In females, IHD, stroke, breast and colon cancer AM rates declined significantly. CONCLUSIONS AND IMPLICATIONS: Despite large declines in AM in Victoria, there are significant differences in rates between the sexes and in the population based on socio-economic status or remoteness. These results provide opportunities for policy makers to prioritise public health and health services interventions, targeting population groups and specific disease conditions to reduce health inequalities.

Effects of increased private health insurance on hospital utilisation in Victoria.

The proportion of Victorians and Australians generally with private health insurance (PHI) increased from 31% in 1998 to 45% in 2001. We analysed a dataset containing all hospital separations throughout Victoria to determine whether changes in the level of private health insurance have had any impact on patterns of public and private hospital utilisation in Victoria. Total utilisation of private hospitals grew by 31% from 1998-99 to 2002-03, whereas utilisation of public hospitals increased by 18%. Total bed-days have increased in both private hospitals and public hospitals by 12%. The proportion of all separations at private hospitals has remained relatively stable between these 2 years, with 33% of all separations being private patients in private hospitals in 1998-99, increasing slightly to 35% by 2002-03. Analysis of a number of specific DRGs shows that patients with more severe disease are more likely to be seen at public hospitals; notably this trend has strengthened between 1998-99 and 2002-03. The number of patients treated in Victorian public hospitals has continued to grow, despite a rapid increase in the utilisation of private hospitals. Given the limited extent of the shift in caseload share between the two sectors, the effectiveness of the Commonwealth's subsidy of private health insurance as a mechanism to reduce pressure on the public sector needs to be carefully examined.

Hospital utilisation among people born in refugee-source countries: an analysis of hospital admissions, Victoria, 1998-2004.

OBJECTIVE: To investigate whether hospital utilisation and health outcomes in Victoria differ between people born in refugee-source countries and those born in Australia. DESIGN AND SETTING: Analysis of a statewide hospital discharge dataset for the 6 financial years from 1 July 1998 to 30 June 2004. Hospital admissions of people born in eight countries for which the majority of entrants to Australia arrived as refugees were included in the analysis. MAIN OUTCOME MEASURES: Age-standardised rates and rate ratios for: total hospital admissions; emergency admissions; surgical admissions; total days in hospital; discharge at own risk; hospital deaths; admissions due to infectious and parasitic diseases; and admissions due to mental and behavioural disorders. RESULTS: In 2003-04, compared with the Australia-born Victorian population, people born in refugee-source countries had lower rates of surgical admission (rate ratio [RR], 0.85; 95% CI, 0.81-0.88), total days in hospital (RR, 0.74; 95% CI, 0.73-0.75), and admission due to mental and behavioural disorders (RR, 0.70; 95% CI, 0.65-0.76). Over the 6-year period, rates of total days in hospital and rates of admission due to mental and behavioural disorders for people born in refugee-source countries increased towards Australian-born averages, while rates of total admissions, emergency admissions, and admissions due to infectious and parasitic diseases increased above the Australian-born averages. CONCLUSIONS: Use of hospital services among people born in refugee-source countries is not higher than that of the Australian-born population and shows a trend towards Australian-born averages. Our findings indicate that the Refugee and Humanitarian Program does not currently place a burden on the Australian hospital system.