Patricia K. Correll

Changes to AIDS dementia complex in the era of highly active antiretroviral therapy

OBJECTIVES To determine the protective efficacy of highly active antiretroviral therapy (HAART) against AIDS dementia complex (ADC) relative to other initial AIDS-defining illnesses (ADIs), Australian AIDS notification data over recent years were examined. METHODS All initial ADIs in Australia over the period 1992-1997 were included. Three initial ADI groups were established: ADC; other predominantly central nervous system (CNS) ADIs (toxoplasmosis and cryptococcosis); and non-CNS ADIs. For each ADI grouping, the proportion of total ADls, and median CD4 cell count in the pre-HAART era (1992-1995) were compared with the HAART era (1996 and 1997). RESULTS Initial ADls peaked in Australia in 1994 (n = 1049), with a gradual decline to 1996 (n = 722), and a marked decline in 1997 (n = 367). ADC constituted 4.4% of initial ADIs over the period 1992-1995, but increased after the introduction of HAART to 6.0% in 1996 and 6.5% in 1997 (P = 0.02). In contrast, the proportion of other CNS ADIs (1992-1995, 8.1%; 1996, 6.0%; 1997, 8.2%; P = 0.41) was stable over the period 1992-1997. The median CD4 cell count at ADC diagnosis increased from 70/mm3 in 1992-1995 to 120/mm3 in 1996 and 170/mm3 in 1997 (P = 0.04). Although the median CD4 cell count also increased significantly over this period for both other CNS ADIs (40-60/mm3; P = 0.02), and non-CNS ADIs (60-70/mm3; P = 0.02), the increase was small. CONCLUSION A proportional increase in ADC compared with other ADIs and a marked increase in the median CD4 cell count at ADC diagnosis have occurred since the introduction of HAART in Australia. These changes suggest that HAART has a lesser impact on ADC than on other ADIs, with the poor CNS penetration of many antiretroviral agents a possible explanation.

Rates of non-AIDS-defining cancers in people with HIV infection before and after AIDS diagnosis.

Objective To describe the incidence of non-AIDS-defining cancers in people with HIV infection before and after the occurrence of AIDS, and to examine the association of cancer risk with immune deficiency. Design Cohort study involving nation-wide linkage of HIV, AIDS and cancer registry data. Methods Association of cancer risk with immune deficiency was examined by analysing cancer risks in four periods between HIV diagnosis, AIDS and death. Results Linkage identified 196 cases of non-AIDS-defining cancer in 8351 people notified with HIV infection and 8118 registered with AIDS (total of 13 067 individuals). Overall, we found significantly increased rates of cancer of the lip, anus, Hodgkins disease, myeloma and leukaemia. Of these cancers, in people with HIV infection who did not develop AIDS, or were more than 5 years prior to development of AIDS, only cancer of the anus occurred at increased rates. A significant trend of increasing relative risk of cancer with increasing time since HIV diagnosis was found for Hodgkins disease and multiple myeloma. Conclusions People with HIV with mild immune deficiency prior to AIDS were at increased risk of anal cancer, but this may reflect other risk factors. Other cancers occurred only later in the course of HIV infection. This is reassuring evidence that people with HIV who are only mildly immune deficient may not be at increased risk of non-AIDS-defining cancers, but larger studies with longer periods of follow-up are needed to confirm this.

Decreasing rates of Kaposi's sarcoma and non-hodgkin's lymphoma in the era of potent combination anti-retroviral therapy

ObjectiveTo describe the changing incidence of Kaposis sarcoma (KS) and non-Hodgkins lymphoma (NHL) in people with HIV in Australia during the time period of introduction of potent combination anti-retroviral therapy. DesignA national, population-based linkage study of cancer and HIV registration data. MethodsWe calculated person-year rates of KS and NHL in people after reporting of HIV diagnosis. Trends in cancer incidence rates were examined, based on four time periods defined by the availability of specific anti-retroviral therapies. ResultsLinkage identified 206 cases of KS and 235 cases of NHL in 8108 people reported with HIV infection. There was an increasing trend in NHL incidence rates over the four time periods (P for trend, 0.012), but incidence for the period since the availability of the new therapies was significantly lower than that for the period immediately prior (incidence rate ratio 0.58; 95% confidence interval, 0.36–0.92). Incidence of KS had been decreasing prior to the new therapies and declined further since their widespread use (P for trend, 0.045). ConclusionsPopulation-based incidence rates of AIDS related KS and NHL have decreased since the widespread use of potent anti-retroviral therapies in Australia. NHL incidence decreased less than KS, and NHL is now the most common AIDS-associated cancer in Australia.

Impact of asthma on self-reported health status and quality of life: a population based study of Australians aged 18–64

Background: The impact of asthma has traditionally been measured in terms of the prevalence of the disease, mortality rates, and levels of healthcare utilisation, particularly hospital admissions. However, the impact of asthma extends beyond these outcomes to include effects on lifestyle, well being, and perceived health status. Methods: Information on self-reported current asthma status, arthritis and diabetes as well as measures of life satisfaction, self-assessed health status, psychological distress, and interference with usual activities was obtained for 14 641 respondents aged 18–64 years in the 2001 National Health Survey of the general population in all states and territories in Australia. Log linear models were fitted separately for each of the dichotomised quality of life measures as dependent variables. The estimates of the adjusted rate ratio obtained from each model were used to compute the population attributable fraction (PAF) of self-reported asthma, arthritis, and diabetes for each of the health status and quality of life measures. Results: The presence of asthma accounted for 3.18% (95% CI 2.13 to 4.23) of people reporting poor life satisfaction, 8.12% (95% CI 6.57 to 9.67) of people reporting poor health status, 5.90% (95% CI 4.19 to 7.61) of people reporting high psychological distress, and 3.58% (95% CI 2.16 to 5.01) of people reporting any reduced activity days. The proportions of people with these adverse health states attributable to asthma were higher than the proportions attributable to diabetes but lower than the proportions attributable to arthritis. Conclusion: Asthma is an important contributor to the burden of ill health and impaired quality of life in the community. A strategic approach is needed to develop and implement strategies to address the impact of asthma on quality of life.

Reattendance at hospital for asthma in two Australian states, 2000–2003

Objective and background:  Reattendance rates at hospitals and emergency departments (ED) can provide a valuable marker of the quality and effectiveness of clinical care. Linked hospital and ED data from New South Wales and Victoria, Australia, were used to examine reattendances for asthma.

Hospital readmissions for asthma: a feasibility study comparing strategies for linking hospital morbidity data

Objective: To investigate whether the variables in the National Hospital Morbidity Database (NHMD) provide sufficient information to validly link hospital admission records for the same person so that persons admitted and re‐admissions for a specified disease can be enumerated.