Heatwave-related Mortality in Australia: Who's impacted the most?

Background

The impacts of heatwaves on the risk of mortality have been well-documented worldwide. However, impacts are not equally spread across the population with certain subgroups and locations affected more than others, warranting local evidence to guide and improve prevention and adaptation strategies. The objectives of this study were to identify the person and area-level socio-demographic, health, and environmental factors that modify the heatwave-mortality association in Australia.

Methods

Warm-season (October-March) mortality (2007-2017) were obtained from the Australian Bureau of Statistics. Heatwaves were defined using Excess Heat Factor, a normalised metric of heatwave severity. A time-stratified case-crossover design was used to model heatwave-mortality associations at the Statistical Areas 2 (SA2) spatial unit. Effect modification by person and area-level factors was assessed using interaction terms.

Results

Nationally, mortality increased by 2% (Relative Risk-RR 1.02; 95%CI: 1.01-1.03) during heatwaves with 1418 excess deaths (95%CI: 723-2113). But impacts varied with the highest effect observed in Adelaide (RR 1.08; 95%CI: 1.04-1.12) and Regional Tasmania (RR 1.11; 95%CI: 1.04-1.18). A gradient of impact was found within locations, for example, vulnerable SA2s in Adelaide were featured by a higher proportion of people in rental housing, inaccessibilities (vehicle and internet), low vegetation, newer houses, and a prevalence of respiratory and psychological diseases. Person-level factors included those: renting privately, with a low English-speaking ability, with chronic health conditions (diabetes, asthma/chronic obstructive pulmonary diseases) and using antidepressants, anxiolytics and sedative medications.

Conclusions

Our results, leveraging person and area-level linked data, highlight the need to consider contextual and individual risk factors and the importance of developing place-based targeted interventions to reduce heatwave health impacts.

Key messages

Heatwaves increase mortality in Australia. Heatwave-vulnerability is determined by individual and community-level factors.

Perceptions of Australian clients towards male radiographers working in breast imaging: Quantitative results from a pilot study

AIM

Breast cancer is the second most common cause of cancer-related death in Australian women, therefore early breast cancer detection is essential. Female radiographers currently conduct breast screening in Australia; however there is a projected shortage. With many women already feeling apprehensive about attending a breast examination, possible proposals to fill this shortage must be carefully considered. Training male radiographers is one proposal however, this raises some gender concerns. This study aimed to pilot an investigation into whether it would change women's willingness to attend breast screening if conducted by a male radiographer.

METHOD

A questionnaire completed by 146 women aged over 40 asked questions on attitude, initial reaction and how they would proceed if attended to by a male in three clinical situations (Mammography; Ultrasound and Breast Surgery).

RESULTS

The results revealed that women would have had their mammogram (90%), ultrasound (95%) and surgery (100%) conducted by a male, though some would have preferred a female for mammography (25%), ultrasound (24%) and surgery (12%). A total of 9% of women agreed to the statement 'If there were male radiographers I would not return for another screening appointment' and 9% agreed to the statement 'if I heard there could be male radiographers it would change my opinion of Breast Screening for the worse'.

CONCLUSIONS

This first Australian study investigating the perceptions of women to male radiographers in the breast screening arena suggest that a mix of male and female radiographers could be accommodated and indicates the need for a larger national survey.

Growth hormone response to clonidine in neuroleptic-free patients with multidagnostically defined schizophrenia

The role of alpha 2-adrenergic receptor sensitivity in schizophrenia was examined by measuring growth hormone (GH) response after the intravenous administration of clonidine (1.3 micrograms/kg) in 26 healthy control subjects and 26 neuroleptic-free, acutely psychotic patients with at least 1 out of 11 possible diagnoses of schizophrenia derived from a multidiagnostic psychopathological assessment. GH responses were significantly (0.01) lower than control values in schizophrenias defined by E. Bleuler, M. Bleuler, Schneider, Langfeldt, Taylor and Abrams, and Cloninger, but not in DSM-III, World Health Organization, Feighner, Kraepelian, and Research Diagnostic Criteria (RDC) schizophrenias. Eight patients with RDC schizoaffective disorder also had a blunted response. However, there were no correlations with any symptom measures. There were no differences between paranoid and nonparanoid patients, although there was a significant difference between nonparanoid patients and control subjects. These findings support the presence of noradrenergic dysfunction in some patients within the schizophrenia syndrome, possibly those whose illnesses have an affective component. The study also illustrates the need for simultaneous investigation of several different sets of diagnostic criteria for schizophrenia in neurobiological research.

Comparison of participants and nonparticipants in a neuroendocrine investigation of psychosis

Of all neuroleptic-naive, acutely psychotic subjects admitted to hospital over a 2-year period (n = 62), 27 participated in a neuroendocrine study and 35 did not participate (51% refused consent, 19% were incapable of consent and 31% started neuroleptics immediately). However, all nonparticipants agreed to psychopathological evaluation, thus allowing comparison between participants and nonparticipants. The 2 groups were similar in most respects, except that more nonparticipants were hostile. Among subjects with schizophrenia, 47% of nonparticipants had the paranoid subtype vs 8% of participants. There was also a trend towards longer illness duration in nonparticipants. These results underline the need for neurobiological studies of psychosis to consider sample bias as a confounding variable.

Relationship of psychotic symptoms to haloperidol-stimulated prolactin release

Prolactin (PRL) response to a single dose of intravenous haloperidol (0.5 mg) was measured as a marker of tuberoinfundibular dopamine (TIDA) activity in 24 neuroleptic-free, male, psychotic patients. The PRL responses were then correlated with psychotic symptoms measured with Andreasen's Scales for the Assessment of Positive and Negative Symptoms (SAPS, SANS). Correlation analyses revealed a significant inverse relationship between PRL response and the severity of delusional symptoms. There was no significant correlation between the symptoms of hallucinations, formal thought disorder, or global negative symptoms and PRL response to haloperidol, nor were there any significant correlations between basal PRL and symptom severity. These results suggest that among the positive and negative symptoms associated with psychoses, only delusions may be associated with TIDA overactivity.

Basal and haloperidol-stimulated prolactin in neuroleptic-free men with schizophrenia defined by 11 diagnostic systems

Forty-four male, neuroleptic-free, acutely psychotic patients with at least one diagnosis of schizophrenia among 11 diagnostic systems, and 28 healthy controls, underwent measurement of prolactin (PRL) concentrations before and after intravenous administration of haloperidol (0.5 mg). Basal PRL concentrations were lower in the patients with Research Diagnostic Criteria (RDC) DSM-III, Cloninger, and Taylor and Abrams schizophrenias than in controls. Compared with the controls, the PRL response to haloperidol was lower in the patients with schizophrenia defined by all diagnostic systems except those of Schneider and M. Bleuler. Neither basal nor stimulated PRL concentrations were correlated with positive symptoms, but basal PRL was correlated with the Brief Psychiatric Rating Scale (BPRS) depression-related subscore. This study lends further support for the presence of dopaminergic dysfunction in schizophrenia, and demonstrates the advantages and problems in the use of multidiagnostic psychopathological evaluation to categorize a disorder where there is major disagreement among diagnostic systems.