Factors driving inequality in prostate cancer survival: a population based study

As cancer control strategies have become more successful, issues around survival have become increasingly important to researchers and policy makers. The aim of this study was to examine the role of a range of clinical and socio-demographic variables in explaining variations in survival after a prostate cancer diagnosis, paying particular attention to the role of healthcare provider(s) i.e. private versus public status. Data were extracted from the National Cancer Registry Ireland, for patients diagnosed with prostate cancer from 1998-2009 (N = 26,183). A series of multivariate Cox and logistic regression models were used to examine the role of healthcare provider and socio-economic status (area-based deprivation) on survival, controlling for age, stage, Gleason grade, marital status and region of residence. Survival was based on all-cause mortality. Older individuals who were treated in a private care setting were more likely to have survived than those who had not, when other factors were controlled for. Differences were evident with respect to marital status, region of residence, clinical stage and Gleason grade. The effect of socio-economic status was modified by healthcare provider, such that risk of death was higher in those men of lower socio-economic status treated by public, but not private providers in the Cox models. The logistic models revealed a socio-economic gradient in risk of death overall; the gradient was larger for those treated by public providers compared to those treated by private providers when controlling for a range of other confounding factors. The role of healthcare provider and socio-economic status in survival of men with prostate cancer may give rise to concerns that warrant further investigation

Factors driving inequality in prostate cancer survival: a population based study.

PURPOSE: As cancer control strategies have become more successful, issues around survival have become increasingly important to researchers and policy makers. The aim of this study was to examine the role of a range of clinical and socio-demographic variables in explaining variations in survival after a prostate cancer diagnosis, paying particular attention to the role of healthcare provider(s) i.e. private versus public status. METHODS: Data were extracted from the National Cancer Registry Ireland, for patients diagnosed with prostate cancer from 1998-2009 (N = 26,183). A series of multivariate Cox and logistic regression models were used to examine the role of healthcare provider and socio-economic status (area-based deprivation) on survival, controlling for age, stage, Gleason grade, marital status and region of residence. Survival was based on all-cause mortality. RESULTS: Older individuals who were treated in a private care setting were more likely to have survived than those who had not, when other factors were controlled for. Differences were evident with respect to marital status, region of residence, clinical stage and Gleason grade. The effect of socio-economic status was modified by healthcare provider, such that risk of death was higher in those men of lower socio-economic status treated by public, but not private providers in the Cox models. The logistic models revealed a socio-economic gradient in risk of death overall; the gradient was larger for those treated by public providers compared to those treated by private providers when controlling for a range of other confounding factors. CONCLUSION: The role of healthcare provider and socio-economic status in survival of men with prostate cancer may give rise to concerns that warrant further investigation

Multivariate logistic regression analysis stratified by healthcare payer (odds ratios reported).

<p>Notes: 1.) Odds Ratios with clustered standard errors (Confidence Intervals in brackets).</p><p>2.) Significance: * (P<0.10), ** (P<0.05), *** (P<0.01).</p><p>3.) “SES”- Socio-economic status.</p><p>Multivariate logistic regression analysis stratified by healthcare payer (odds ratios reported).</p

Multivariate stratified Cox regression for 84 month survival.

<p>Notes: 1.) Hazard Ratios for not surviving at 36 months reported with clustered standard errors.</p><p>2.) Significance: * (P<0.10), ** (P<0.05), *** (P<0.01).</p><p>3.) “SES”- Socio-economic status.</p><p>Multivariate stratified Cox regression for 84 month survival.</p

Characteristics of prostate cancer cases diagnosed from 1998–2009¹, included in analysis.

<p>1.) 26,938 diagnosed in 1998–2009 but (n = 122) excluded from analysis due to missing data.</p><p>2.) MOP- method of presentation.</p><p>3.) SES Unk- Socio-economic status unknown.</p><p>Characteristics of prostate cancer cases diagnosed from 1998–2009¹, included in analysis.</p

Multivariate stratified Cox regression for 36 month survival.

<p>Notes: 1.) Hazard Ratios for not surviving at 36 months reported with clustered standard errors.</p><p>2.) Significance: * (P<0.10), ** (P<0.05), *** (P<0.01).</p><p>3.) “SES”- Socio-economic status.</p><p>Multivariate stratified Cox regression for 36 month survival.</p

Crude hazard ratios for healthcare provider by year of diagnosis for men diagnosed with prostate cancer (1998–2009).

<p><b>a</b>. This graph contains 12 individual Cox PH models where the base category is ‘Public Payer’ for varying follow-up periods up to 31/12/10. <b>b</b>. All Hazard Ratios presented are statistically significant and confidence intervals are depicted by the line segments. <b>c</b> The test of proportional hazards (global test) revealed marginal non-proportionality for models with the following year of diagnosis: 1998, 2002, 2003, 2004; therefore caution is warranted in interpretation; however overall men with access to private healthcare had a lower risk of death than those who did not have access.</p

Risk of Several Cancers is Higher in Urban Areas after Adjusting for Socioeconomic Status. Results from a Two-Country Population-Based Study of 18 Common Cancers

Some studies suggest that there are urban–rural variations in cancer incidence but whether these simply reflect urban–rural socioeconomic variation is unclear. We investigated whether there were urban–rural variations in the incidence of 18 cancers, after adjusting for socioeconomic status. Cancers diagnosed between 1995 and 2007 were extracted from the population-based National Cancer Registry Ireland and Northern Ireland Cancer Registry and categorised by urban–rural status, based on population density of area of residence at diagnosis (rural <1 person per hectare, intermediate 1–15 people per hectare, urban >15 people per hectare). Relative risks (RR) were calculated by negative binomial regression, adjusting for age, country and three area-based markers of socioeconomic status. Risks were significantly higher in both sexes in urban than rural residents with head and neck (males RR urban vs. rural = 1.53, 95 % CI 1.42–1.64; females RR = 1.29, 95 % CI 1.15–1.45), esophageal (males 1.21, 1.11–1.31; females 1.21, 1.08–1.35), stomach (males 1.36, 1.27–1.46; females 1.19, 1.08–1.30), colorectal (males 1.14, 1.09–1.18; females 1.04, 1.00–1.09), lung (males 1.54, 1.47–1.61; females 1.74, 1.65–1.84), non-melanoma skin (males 1.13, 1.10–1.17; females 1.23, 1.19–1.27) and bladder (males 1.30, 1.21–1.39; females 1.31, 1.17–1.46) cancers. Risks of breast, cervical, kidney and brain cancer were significantly higher in females in urban areas. Prostate cancer risk was higher in rural areas (0.94, 0.90–0.97). Other cancers showed no significant urban–rural differences. After adjusting for socioeconomic variation, urban–rural differences were evident for 12 of 18 cancers. Variations in healthcare utilization and known risk factors likely explain some of the observed associations. Explanations for others are unclear and, in the interests of equity, warrant further investigation