David Banham1, David Roder2, Alex Brown3. 1. Wardliparingga Aboriginal Research Unit, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia; Centre for Population Health Research, School of Health Sciences, Sansom Institute for Health Research, University of South Australia, North Terrace, Adelaide, SA, 5000, Australia. Electronic address: david.banham@sahmri.com. 2. Centre for Population Health Research, School of Health Sciences, Sansom Institute for Health Research, University of South Australia, North Terrace, Adelaide, SA, 5000, Australia. 3. Wardliparingga Aboriginal Research Unit, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia; Aboriginal Health Research Group, Sansom Institute for Health Research, University of South Australia, North Terrace, Adelaide, SA, 5000, Australia.
Abstract
BACKGROUND: Aboriginal Australians have poorer cancer survival than other Australians. Diagnoses at later stages and correlates of remote area living influence, but do not fully explain, these disparities. Little is known of the prevalence and influence of comorbid conditions experienced by Aboriginal people, including their effect on cancer survival. This study quantifies hospital recorded comorbidities using the Elixhauser Comorbidity Index (ECI), examines their influence on risk of cancer death, then considers effect variation by Aboriginality. METHODS:Cancers diagnosed among Aboriginal South Australians in 1990-2010 (N = 777) were matched with randomly selected non-Aboriginal cases by birth year, diagnostic year, sex, and primary site, then linked to administrative hospital records to the time of diagnosis. Competing risk regression summarised associations of Aboriginal status, stage, geographic attributes and comorbidities with risk of cancer death. RESULTS: A threshold of four or more ECI conditions was associated with increased risk of cancer death (sub-hazard ratio SHR 1.66, 95%CI 1.11-2.46). Alternatively, the presence of any one of a subset of ECI conditions was associated with similarly increased risk (SHR = 1.62, 95%CI 1.23-2.14). The observed effects did not differ between Aboriginal and matched non-Aboriginal cases. However, Aboriginal cases experienced three times higher exposure than non-Aboriginal to four or more ECI conditions (14.2% versus 4.5%) and greater exposure to the subset of ECI conditions (20.7% versus 8.0%). CONCLUSION: Comorbidities at diagnosis increased the risk of cancer death in addition to risks associated with Aboriginality, remoteness of residence and disease stage at diagnosis. The Aboriginal cohort experienced comparatively greater exposure to comorbidities which adds to disparities in cancer outcomes.
RCT Entities:
BACKGROUND: Aboriginal Australians have poorer cancer survival than other Australians. Diagnoses at later stages and correlates of remote area living influence, but do not fully explain, these disparities. Little is known of the prevalence and influence of comorbid conditions experienced by Aboriginal people, including their effect on cancer survival. This study quantifies hospital recorded comorbidities using the Elixhauser Comorbidity Index (ECI), examines their influence on risk of cancer death, then considers effect variation by Aboriginality. METHODS:Cancers diagnosed among Aboriginal South Australians in 1990-2010 (N = 777) were matched with randomly selected non-Aboriginal cases by birth year, diagnostic year, sex, and primary site, then linked to administrative hospital records to the time of diagnosis. Competing risk regression summarised associations of Aboriginal status, stage, geographic attributes and comorbidities with risk of cancer death. RESULTS: A threshold of four or more ECI conditions was associated with increased risk of cancer death (sub-hazard ratio SHR 1.66, 95%CI 1.11-2.46). Alternatively, the presence of any one of a subset of ECI conditions was associated with similarly increased risk (SHR = 1.62, 95%CI 1.23-2.14). The observed effects did not differ between Aboriginal and matched non-Aboriginal cases. However, Aboriginal cases experienced three times higher exposure than non-Aboriginal to four or more ECI conditions (14.2% versus 4.5%) and greater exposure to the subset of ECI conditions (20.7% versus 8.0%). CONCLUSION: Comorbidities at diagnosis increased the risk of cancer death in addition to risks associated with Aboriginality, remoteness of residence and disease stage at diagnosis. The Aboriginal cohort experienced comparatively greater exposure to comorbidities which adds to disparities in cancer outcomes.
Authors: Lettie Pule; Elizabeth Buckley; Theophile Niyonsenga; David Banham; David Roder Journal: BMC Health Serv Res Date: 2018-10-16 Impact factor: 2.655
Authors: David Banham; David Roder; Dorothy Keefe; Gelareh Farshid; Marion Eckert; Natasha Howard; Karla Canuto; Alex Brown Journal: BMC Health Serv Res Date: 2019-06-14 Impact factor: 2.655
Authors: David Banham; David Roder; Marion Eckert; Natasha J Howard; Karla Canuto; Alex Brown Journal: BMC Health Serv Res Date: 2019-10-29 Impact factor: 2.655