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1.
Cancer Epidemiol ; 90: 102576, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38696968

ABSTRACT

BACKGROUND: Cancer survival is a key component to assess the overall effectiveness of healthcare systems in their cancer management efforts. A key supporting tool for planning and decision making was introduced with the development of an index of cancer survival that summarises survival for all adults and cancer types into one single estimate, but the implementation details have not been previously described. METHODS: We detail the construction of the index, including the structure, the calculation of 'sex-age-cancer' specific weights and our proposed modelling strategy to estimate net survival. We provide some practical recommendations through an illustration using a synthetic dataset ('Replica') that we generated for this purpose. An example of R code usage to estimate the index using our approach is provided. RESULTS: The 'Replica' contains 500 000 artificial cancer records that mimic a cohort of adult cancer patients diagnosed with cancer in England between 1980 and 2004. Using this dataset, we estimated an index of cancer survival at one, five, and ten years after diagnosis for five selected periods of diagnosis, and provide an example of interpretation of these results. DISCUSSION: We propose a flexible penalised regression modelling strategy to estimate the index's 'sex-age-cancer' specific cancer survival components that minimises the estimation challenge of these components. This tutorial will support researchers in constructing an index of cancer survival for their own setting, facilitating the enrichment of existing toolkits of cancer indicators to more effectively measure progress against cancer in their respective regions/countries.


Subject(s)
Neoplasms , Humans , Neoplasms/mortality , Female , Male , Adult , Survival Rate , England/epidemiology , Middle Aged , Aged
2.
Stat Methods Med Res ; 33(4): 681-701, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38444377

ABSTRACT

Relative survival represents the preferred framework for the analysis of population cancer survival data. The aim is to model the survival probability associated with cancer in the absence of information about the cause of death. Recent data linkage developments have allowed for incorporating the place of residence into the population cancer databases; however, modeling this spatial information has received little attention in the relative survival setting. We propose a flexible parametric class of spatial excess hazard models (along with inference tools), named "Relative Survival Spatial General Hazard," that allows for the inclusion of fixed and spatial effects in both time-level and hazard-level components. We illustrate the performance of the proposed model using an extensive simulation study, and provide guidelines about the interplay of sample size, censoring, and model misspecification. We present a case study using real data from colon cancer patients in England. This case study illustrates how a spatial model can be used to identify geographical areas with low cancer survival, as well as how to summarize such a model through marginal survival quantities and spatial effects.


Subject(s)
Colonic Neoplasms , Humans , Proportional Hazards Models , Survival Analysis , Computer Simulation , Sample Size , Models, Statistical
3.
Ethn Health ; 29(1): 46-61, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37642313

ABSTRACT

OBJECTIVES: There is limited evidence regarding the impact of race/racism and its intersection with socioeconomic status (SES) on breast and cervical cancer, the two most common female cancers globally. We investigated racial inequalities in breast and cervical cancer mortality and whether SES (education and household conditions) interacted with race/ethnicity. DESIGN: The 100 Million Brazilian Cohort data were linked to the Brazilian Mortality Database, 2004-2015 (n = 20,665,005 adult women). We analysed the association between self-reported race/ethnicity (White/'Parda'(Brown)/Black/Asian/Indigenous) and cancer mortality using Poisson regression, adjusting for age, calendar year, education, household conditions and area of residence. Additive and multiplicative interactions were assessed. RESULTS: Cervical cancer mortality rates were higher among Indigenous (adjusted Mortality rate ratio = 1.80, 95%CI 1.39-2.33), Asian (1.63, 1.20-2.22), 'Parda'(Brown) (1.27, 1.21-1.33) and Black (1.18, 1.09-1.28) women vs White women. Breast cancer mortality rates were higher among Black (1.10, 1.04-1.17) vs White women. Racial inequalities in cervical cancer mortality were larger among women of poor household conditions, and low education (P for multiplicative interaction <0.001, and 0.02, respectively). Compared to White women living in completely adequate (3-4) household conditions, the risk of cervical cancer mortality in Black women with 3-4, 1-2, and none adequate conditions was 1.10 (1.01-1.21), 1.48 (1.28-1.71), and 2.03 (1.56-2.63), respectively (Relative excess risk due to interaction-RERI = 0.78, 0.18-1.38). Among 'Parda'(Brown) women the risk was 1.18 (1.11-1.25), 1.68 (1.56-1.81), and 1.84 (1.63-2.08), respectively (RERI = 0.52, 0.16-0.87). Compared to high-educated White women, the risk in high-, middle- and low-educated Black women was 1.14 (0.83-1.55), 1.93 (1.57-2.38) and 2.75 (2.33-3.25), respectively (RERI = 0.36, -0.05-0.77). Among 'Parda'(Brown) women the risk was 1.09 (0.91-1.31), 1.99 (1.70-2.33) and 3.03 (2.61-3.52), respectively (RERI = 0.68, 0.48-0.88). No interactions were found for breast cancer. CONCLUSION: Low SES magnified racial inequalities in cervical cancer mortality. The intersection between race/ethnicity, SES and gender needs to be addressed to reduce racial health inequalities.


Subject(s)
Breast Neoplasms , Health Inequities , Uterine Cervical Neoplasms , Adult , Female , Humans , Brazil/epidemiology , Breast Neoplasms/mortality , Ethnicity , Social Class , Socioeconomic Factors , Uterine Cervical Neoplasms/mortality , Racial Groups
4.
Br J Cancer ; 130(1): 88-98, 2024 01.
Article in English | MEDLINE | ID: mdl-37741899

ABSTRACT

BACKGROUND: Individual and tumour factors only explain part of observed inequalities in colorectal cancer survival in England. This study aims to investigate inequalities in treatment in patients with colorectal cancer. METHODS: All patients diagnosed with colorectal cancer in England between 2012 and 2016 were followed up from the date of diagnosis (state 1), to treatment (state 2), death (state 3) or censored at 1 year after the diagnosis. A multistate approach with flexible parametric model was used to investigate the effect of income deprivation on the probability of remaining alive and treated in colorectal cancer. RESULTS: Compared to the least deprived quintile, the most deprived with stage I-IV colorectal cancer had a lower probability of being alive and treated at all the time during follow-up, and a higher probability of being untreated and of dying. The probability differences (most vs. least deprived) of being alive and treated at 6 months ranged between -2.4% (95% CI: -4.3, -1.1) and -7.4% (-9.4, -5.3) for colon; between -2.0% (-3.5, -0.4) and -6.2% (-8.9, -3.5) for rectal cancer. CONCLUSION: Persistent inequalities in treatment were observed in patients with colorectal cancer at every stage, due to delayed access to treatment and premature death.


Subject(s)
Colorectal Neoplasms , Rectal Neoplasms , Humans , Socioeconomic Factors , England/epidemiology , Colorectal Neoplasms/pathology , Rectal Neoplasms/therapy , Registries
6.
Qual Life Res ; 32(11): 3123-3133, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37389733

ABSTRACT

OBJECTIVE: To investigate associations between quality of life (QoL) and 1) immunotherapy and other cancer treatments received three months before QoL measurements, and 2) the comorbidities at the time of completion or in the year prior to QoL measurements, among patients with advanced cancer. METHODS: A cross-sectional study is conducted on patients with advanced cancer in the Netherlands. The data come from the baseline wave of the 2017-2020 eQuiPe study. Participants were surveyed via questionnaires (including EORTC QLQ-C30). Using multivariable linear and logistic regression models, we explored statistical associations between QoL components and immunotherapy and other cancer treatments as well as pre-existing comorbidities while adjusting for age, sex, socio-economic status. RESULTS: Of 1088 participants with median age 67 years, 51% were men. Immunotherapy was not associated with global QoL but was associated with reduced appetite loss (odds ratio (OR) = 0.6, 95%CI = [0.3,0.9]). Reduced global QoL was associated with chemotherapy (adjusted mean difference (ß) = - 4.7, 95% CI [- 8.5,- 0.8]), back pain (ß = - 7.4, 95% CI [- 11.0,- 3.8]), depression (ß = - 13.8, 95% CI [- 21.5,- 6.2]), thyroid diseases (ß = - 8.9, 95% CI [- 14.0,- 3.8]) and diabetes (ß = - 4.5, 95% CI [- 8.9,- 0.5]). Chemotherapy was associated with lower physical (OR = 2.4, 95% CI [1.5,3.9]) and role (OR = 1.8, 95% CI [1.2,2.7]) functioning, and higher pain (OR = 1.9, 95% CI [1.3,2.9]) and fatigue (OR = 1.6, 95% CI [1.1,2.4]). CONCLUSION: Our study identified associations between specific cancer treatments, lower QoL and more symptoms. Monitoring symptoms may improve QoL of patients with advanced cancer. Producing more evidence from real life data would help physicians in better identifying patients who require additional supportive care.


Subject(s)
Neoplasms , Quality of Life , Male , Humans , Aged , Female , Quality of Life/psychology , Cross-Sectional Studies , Netherlands/epidemiology , Neoplasms/therapy , Comorbidity , Surveys and Questionnaires
7.
Accid Anal Prev ; 174: 106726, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35716544

ABSTRACT

The goal of this paper was to measure the effect of Human-Machine Interface (HMI) information and guidance on drivers' gaze and takeover behaviour during transitions of control from automation. The motivation for this study came from a gap in the literature, where previous research reports improved performance of drivers' takeover based on HMI information, without considering its effect on drivers' visual attention distribution, and how drivers also use the information available in the environment to guide their response. This driving simulator study investigated drivers' lane-changing behaviour after resumption of control from automation. Different levels of information were provided on a dash-based HMI, prior to each lane change, to investigate how drivers distribute their attention between the surrounding environment and the HMI. The difficulty of the lane change was also manipulated by controlling the position of approaching vehicles in drivers' offside lane. Results indicated that drivers' decision-making time was sensitive to the presence of nearby vehicles in the offside lane, but not directly influenced by the information on the HMI. In terms of gaze behaviour, the closer the position of vehicles in the offside lane, the longer drivers looked in that direction. Drivers looked more at the HMI, and less towards the road centre, when the HMI presented information about automation status, and included an advisory message indicating it was safe to change lane. Machine learning techniques showed a strong relationship between drivers' gaze to the information presented on the HMI, and decision-making time (DMT). These results contribute to our understanding of HMI design for automated vehicles, by demonstrating the attentional costs of an overly-informative HMI, and that drivers still rely on environmental information to perform a lane-change, even when the same information can be acquired by the HMI of the vehicle.


Subject(s)
Accidents, Traffic , Automobile Driving , Automation , Humans , Motivation
8.
J Epidemiol Community Health ; 76(2): 196-205, 2022 02.
Article in English | MEDLINE | ID: mdl-34400515

ABSTRACT

BACKGROUND: Marked geographical disparities in survival from colon cancer have been consistently described in England. Similar patterns have been observed within London, almost mimicking a microcosm of the country's survival patterns. This evidence has suggested that the area of residence plays an important role in the survival from cancer. METHODS: We analysed the survival from colon cancer of patients diagnosed in 2006-2013, in a pre-pandemic period, living in London at their diagnosis and received care in a London hospital. We examined the patterns of patient pathways between the area of residence and the hospital of care using flow maps, and we investigated whether geographical variations in survival from colon cancer are associated with the hospital of care. To estimate survival, we applied a Bayesian excess hazard model which accounts for the hierarchical structure of the data. RESULTS: Geographical disparities in colon cancer survival disappeared once controlled for hospitals, and the disparities seemed to be augmented between hospitals. However, close examination of patient pathways revealed that the poorer survival observed in some hospitals was mostly associated with higher proportions of emergency diagnosis, while their performance was generally as expected for patients diagnosed through non-emergency routes. DISCUSSION: This study highlights the need to better coordinate primary and secondary care sectors in some areas of London to improve timely access to specialised clinicians and diagnostic tests. This challenge remains crucially relevant after the recent successive regroupings of Clinical Commissioning Groups (which grouped struggling areas together) and the observed exacerbation of disparities during the COVID-19 pandemic.


Subject(s)
COVID-19 , Colonic Neoplasms , Bayes Theorem , Colonic Neoplasms/therapy , Humans , London/epidemiology , Pandemics , SARS-CoV-2 , Survival Analysis
9.
J Epidemiol Community Health ; 75(12): 1155-1164, 2021 12.
Article in English | MEDLINE | ID: mdl-34049927

ABSTRACT

BACKGROUND: Despite persistent reports of socioeconomic inequalities in colorectal cancer survival in England, the magnitude of survival differences has not been fully evaluated. METHODS: Patients diagnosed with colon cancer (n=68 169) and rectal cancer (n=38 267) in England (diagnosed between January 2010 and March 2013) were analysed as a retrospective cohort study using the National Cancer Registry data linked with other population-based healthcare records. The flexible parametric model incorporating time-varying covariates was used to assess the difference in excess hazard of death and in net survival between the most affluent and the most deprived groups over time. RESULTS: Survival analyses showed a clear pattern by deprivation. Hazard ratio of death was consistently higher in the most deprived group than the least deprived for both colon and rectal cancer, ranging from 1.08 to 1.17 depending on the model. On the net survival scale, the socioeconomic gap between the most and the least deprived groups reached approximately -4% at the maximum (-3.7%, 95% CI -1.6 to -5.7% in men, -3.6%, 95% CI -1.6 to -5.7% in women) in stages III for colon and approximately -2% (-2.3%, 95% CI -0.2 to -4.5% in men, -2.3%, 95% CI -0.2 to -4.3% in women) in stage II for rectal cancer at 3 years from diagnosis, after controlling for age, emergency presentation, receipt of resection and comorbidities. The gap was smaller in other stages and sites. For both cancers, patients with emergency presentation persistently had a higher excess hazard of death than those without emergency presentation. CONCLUSION: Survival disparities were profound particularly among patients in the stages, which benefit from appropriate and timely treatment. For the patients with emergency presentation, excess hazard of death remained high throughout three years from the diagnosis. Public health measures should be taken to reduce access inequalities to improve survival disparities.


Subject(s)
Colonic Neoplasms , Colorectal Neoplasms , Female , Humans , Male , Proportional Hazards Models , Retrospective Studies , Socioeconomic Factors , Survival Analysis
10.
Cancer Epidemiol ; 71(Pt A): 101896, 2021 04.
Article in English | MEDLINE | ID: mdl-33516139

ABSTRACT

BACKGROUND: A persistent socioeconomic gap in colon cancer survival is observed in England. Provision of cancer care may also vary by socioeconomic status (SES). We investigated population-based data to explore differential surgical care by SES. METHODS: We analysed a retrospective cohort of patients diagnosed with colon cancer in England (2010-2013). We examined patterns of presentation and surgery by SES, and whether socioeconomic differences exist in the length of time from diagnosis to elective major resection using linear regression. RESULTS: Among a total of 68 169 patients with colon cancer, 21.0 % (3138/14 917) in the most affluent group had emergency presentation (EP) whereas 27.9 % (2901/10 386) in the most deprived. Among 45 332 (66.5 %) patients who underwent resection, the proportion of patients receiving urgent surgery (surgery before or ≤ 7 days of diagnosis) was higher in the most deprived group (39.9 %, 2685/6733) than the most affluent (35.4 %, 3595/10 146). Days from diagnosis to elective surgery (surgery > 7 days after diagnosis) ranged from 33.9 (95 % CI 33.1-34.8) in stage II to 38.2 (95 % CI 36.8-39.7) in stage I, but no socioeconomic differences in time were seen in all stages. CONCLUSIONS: Time to elective surgery for colon cancer did not differ by SES, whereas a higher proportion among deprived patients tended to be diagnosed through EP and to receive urgent surgery. These results suggest that the waiting time target may not be an appropriate measure to assess access to cancer care. Reducing both EP and urgent surgery should be a key policy target.


Subject(s)
Colonic Neoplasms/surgery , Elective Surgical Procedures/statistics & numerical data , Healthcare Disparities/economics , Social Class , Aged , Aged, 80 and over , Colonic Neoplasms/epidemiology , England/epidemiology , Female , Humans , Male , Retrospective Studies , Socioeconomic Factors , Time Factors
11.
Accid Anal Prev ; 148: 105788, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33039820

ABSTRACT

This driving simulator study compared drivers' eye movements during a series of lane-changes, which required different levels of motor control for their execution. Participants completed 12 lane-changing manoeuvres in three drives, categorised by degree of manual engagement with the driving task: Fully Manual Drive, Manual Intervention Required, Fully Automated Drive (Manual drive, Partial automation, Full automation). For Partial automation, drivers resumed control from the automated system and changed lane manually. For Full automation, the automated system managed the lane change, but participants initiated the manoeuvre by pulling the indicator lever. Results were compared to the Manual drive condition, where drivers controlled the vehicle at all times. For each driving condition, lane changing was initiated by drivers, at their discretion, in response to a slow-moving lead vehicle, which entered their lane. Failure to change lane did not result in a collision. To understand how different motor control requirements affected driver visual attention, eye movements to the road centre, and drivers' vertical and horizontal gaze dispersion were compared during different stages of the lane change manoeuvre, for the three drives. Results showed that drivers' attention to the road centre was generally lower for drives with less motor control requirements, especially when they were not engaged in the lane change process. However, as drivers moved closer to the lead vehicle, and prepared to change lane, the pattern of eye movements to the road centre converged, regardless of whether drivers were responsible for the manual control of the lane change. While there were no significant differences in horizontal gaze dispersion between the three drives, vertical dispersion for the two levels of automation was quite different, with higher dispersion during Partial automation, which was due to a higher reliance on the HMI placed in the centre console.


Subject(s)
Accidents, Traffic , Automation , Automobile Driving , Fixation, Ocular , Accidents, Traffic/prevention & control , Humans , Reaction Time
12.
Lancet Glob Health ; 8(9): e1203-e1212, 2020 09.
Article in English | MEDLINE | ID: mdl-32827482

ABSTRACT

BACKGROUND: Breast cancer is the second leading cause of death from cancer in women in sub-Saharan Africa, yet there are few well characterised large-scale survival studies with complete follow-up data. We aimed to provide robust survival estimates in women in this setting and apportion the survival gaps. METHODS: The African Breast Cancer-Disparities in Outcomes (ABC-DO) prospective cohort study was done at eight hospitals across five sub-Saharan African countries (Namibia, Nigeria, South Africa, Uganda, and Zambia). We prospectively recruited women (aged ≥18 years) who attended these hospitals with suspected breast cancer. Women were actively followed up by use of a telephone call once every 3 months, and a mobile health application was used to keep a dynamic record of follow-up calls due. We collected detailed sociodemographic, clinical, and treatment data. The primary outcome was 3-year overall survival, analysed by use of flexible proportional mortality models, and we predicted survival under scenarios of modified distributions of risk factors. FINDINGS: Between Sept 8, 2014, and Dec 31, 2017, 2313 women were recruited from these eight hospitals, of whom 85 did not have breast cancer. Of the remaining 2228 women with breast cancer, 58 women with previous treatment or recurrence, and 14 women from small racial groups (white and Asian women in South Africa), were excluded. Of the 2156 women analysed, 1840 (85%) were histologically confirmed, 129 (6%) were cytologically confirmed, and 187 (9%) were clinically confirmed to have breast cancer. 2156 (97%) women were followed up for up to 3 years or up to Jan 1, 2019, whichever was earlier. Up to this date, 879 (41%) of these women had died, 1118 (52%) were alive, and 159 (7%) were censored early. 3-year overall survival was 50% (95% CI 48-53), but we observed variations in 3-year survival between different races in Namibia (from 90% in white women to 56% in Black women) and in South Africa (from 76% in mixed-race women to 59% in Black women), and between different countries (44-47% in Uganda and Zambia vs 36% in Nigeria). 215 (10%) of all women had died within 6 months of diagnosis, but 3-year overall survival remained low in women who survived to this timepoint (58%). Among survival determinants, improvements in early diagnosis and treatment were predicted to contribute to the largest increases in survival, with a combined absolute increase in survival of up to 22% in Nigeria, Zambia, and Uganda, when compared with the contributions of other factors (such as HIV or aggressive subtypes). INTERPRETATION: Large variations in breast cancer survival in sub-Saharan African countries indicate that improvements are possible. At least a third of the projected 416 000 breast cancer deaths that will occur in this region in the next decade could be prevented through achievable downstaging and improvements in treatment. Improving survival in socially disadvantaged women warrants special attention. FUNDING: Susan G Komen and the International Agency for Research on Cancer.


Subject(s)
Breast Neoplasms/mortality , Adult , Africa South of the Sahara/epidemiology , Aged , Breast Neoplasms/therapy , Female , Humans , Middle Aged , Prospective Studies , Survival Rate
13.
Stat Methods Med Res ; 29(6): 1700-1714, 2020 06.
Article in English | MEDLINE | ID: mdl-31502511

ABSTRACT

Excess hazard models became the preferred modelling tool in population-based cancer survival research. In this setting, the model is commonly formulated as the additive decomposition of the overall hazard into two components: the excess hazard due to the cancer of interest and the population hazard due to all other causes of death. We introduce a flexible Bayesian regression model for the log-excess hazard where the baseline log-excess hazard and any non-linear effects of covariates are modelled using low-rank thin plate splines. Using this type of splines will ensure that the log-likelihood function retains tractability not requiring numerical integration. We demonstrate how to derive posterior distributions for the excess hazard and for net survival, a population-level measure of cancer survival that can be derived from excess hazard models. We illustrate the proposed model using survival data for patients diagnosed with colon cancer during 2009 in London, England.


Subject(s)
Colonic Neoplasms , Bayes Theorem , England , Humans , London , Proportional Hazards Models , Survival Analysis
14.
Thorax ; 74(1): 51-59, 2019 01.
Article in English | MEDLINE | ID: mdl-30100577

ABSTRACT

INTRODUCTION: We investigated socioeconomic disparities and the role of the main prognostic factors in receiving major surgical treatment in patients with lung cancer in England. METHODS: Our study comprised 31 351 patients diagnosed with non-small cell lung cancer in England in 2012. Data from the national population-based cancer registry were linked to Hospital Episode Statistics and National Lung Cancer Audit data to obtain information on stage, performance status and comorbidities, and to identify patients receiving major surgical treatment. To describe the association between prognostic factors and surgery, we performed two different analyses: one using multivariable logistic regression and one estimating cause-specific hazards for death and surgery. In both analyses, we used multiple imputation to deal with missing data. RESULTS: We showed strong evidence that the comorbidities 'congestive heart failure', 'cerebrovascular disease' and 'chronic obstructive pulmonary disease' reduced the receipt of surgery in early stage patients. We also observed gender differences and substantial age differences in the receipt of surgery. Despite accounting for sex, age at diagnosis, comorbidities, stage at diagnosis, performance status and indication of having had a PET-CT scan, the socioeconomic differences persisted in both analyses: more deprived people had lower odds and lower rates of receiving surgery in early stage lung cancer. DISCUSSION: Comorbidities play an important role in whether patients undergo surgery, but do not completely explain the socioeconomic difference observed in early stage patients. Future work investigating access to and distance from specialist hospitals, as well as patient perceptions and patient choice in receiving surgery, could help disentangle these persistent socioeconomic inequalities.


Subject(s)
Carcinoma, Non-Small-Cell Lung/epidemiology , Carcinoma, Non-Small-Cell Lung/surgery , Healthcare Disparities , Lung Neoplasms/epidemiology , Lung Neoplasms/surgery , Poverty , Age Factors , Aged , Aged, 80 and over , Carcinoma, Non-Small-Cell Lung/diagnostic imaging , Carcinoma, Non-Small-Cell Lung/pathology , Cerebrovascular Disorders/epidemiology , Comorbidity , England/epidemiology , Female , Health Status , Heart Failure/epidemiology , Humans , Lung Neoplasms/diagnostic imaging , Lung Neoplasms/secondary , Male , Middle Aged , Neoplasm Staging , Positron Emission Tomography Computed Tomography/statistics & numerical data , Prognosis , Pulmonary Disease, Chronic Obstructive/epidemiology , Pulmonary Surgical Procedures/statistics & numerical data , Sex Factors
15.
BMC Med Res Methodol ; 16(1): 129, 2016 10 01.
Article in English | MEDLINE | ID: mdl-27716079

ABSTRACT

BACKGROUND: In population-based cancer research, piecewise exponential regression models are used to derive adjusted estimates of excess mortality due to cancer using the Poisson generalized linear modelling framework. However, the assumption that the conditional mean and variance of the rate parameter given the set of covariates x i are equal is strong and may fail to account for overdispersion given the variability of the rate parameter (the variance exceeds the mean). Using an empirical example, we aimed to describe simple methods to test and correct for overdispersion. METHODS: We used a regression-based score test for overdispersion under the relative survival framework and proposed different approaches to correct for overdispersion including a quasi-likelihood, robust standard errors estimation, negative binomial regression and flexible piecewise modelling. RESULTS: All piecewise exponential regression models showed the presence of significant inherent overdispersion (p-value <0.001). However, the flexible piecewise exponential model showed the smallest overdispersion parameter (3.2 versus 21.3) for non-flexible piecewise exponential models. CONCLUSION: We showed that there were no major differences between methods. However, using a flexible piecewise regression modelling, with either a quasi-likelihood or robust standard errors, was the best approach as it deals with both, overdispersion due to model misspecification and true or inherent overdispersion.


Subject(s)
Breast Neoplasms/mortality , Survival Analysis , Female , Humans , Models, Statistical , Mortality , Regression Analysis
17.
Br J Cancer ; 115(7): 876-86, 2016 09 27.
Article in English | MEDLINE | ID: mdl-27537388

ABSTRACT

BACKGROUND: Campaigns aimed at raising cancer awareness and encouraging early presentation have been implemented in England. However, little is known about whether people with low cancer awareness and increased barriers to seeking medical help have worse cancer survival, and whether there is a geographical variation in cancer awareness and barriers in England. METHODS: From population-based surveys (n=35 308), using the Cancer Research UK Cancer Awareness Measure, we calculated the age- and sex-standardised symptom awareness and barriers scores for 52 primary care trusts (PCTs). These measures were evaluated in relation to the sex-, age-, and type of cancer-standardised cancer survival index of the corresponding PCT, from the National Cancer Registry, using linear regression. Breast, lung, and bowel cancer survival were analysed separately. RESULTS: Cancer symptom awareness and barriers scores varied greatly between geographical regions in England, with the worst scores observed in socioeconomically deprived parts of East London. Low cancer awareness score was associated with poor cancer survival at PCT level (estimated slope=1.56, 95% CI: 0.56; 2.57). The barriers score was not associated with overall cancer survival, but it was associated with breast cancer survival (estimated slope=-0.66, 95% CI: -1.20; -0.11). Specific barriers, such as embarrassment and difficulties in arranging transport to the doctor's surgery, were associated with worse breast cancer survival. CONCLUSIONS: Cancer symptom awareness and cancer survival are associated. Campaigns should focus on improving awareness about cancer symptoms, especially in socioeconomically deprived areas. Efforts should be made to alleviate barriers to seeking medical help in women with symptoms of breast cancer.


Subject(s)
Health Knowledge, Attitudes, Practice , Health Services Accessibility , Neoplasms/psychology , Patient Acceptance of Health Care , Social Determinants of Health , Communication Barriers , Emotions , England/epidemiology , Female , Geography, Medical , Health Care Surveys , Health Promotion/organization & administration , Health Services Needs and Demand , Humans , Male , Neoplasms/mortality , Poverty Areas , Primary Health Care/organization & administration , Symptom Assessment
18.
J Epidemiol Community Health ; 69(10): 985-92, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26047831

ABSTRACT

BACKGROUND: Non-small cell lung cancer (NSCLC) comprises approximately 85% of all lung cancer cases, and surgery is the preferred treatment for patients. The National Health Service established Primary Care Trusts (PCTs) in 2002 to manage local health needs. We investigate whether PCTs with a lower uptake of surgical treatment are those with above-average mortality 1 year after diagnosis. The applied methods can be used to monitor the performance of any administrative bodies responsible for the management of patients with cancer. METHODS: All adults diagnosed with NSCLC lung cancer during 1998-2006 in England were identified. We fitted mixed effect logistic models to predict surgical treatment within 6 months after diagnosis, and mortality within 1 year of diagnosis. RESULTS: Around 10% of the NCSLC patients received curative surgery. Older deprived patients and those who did not receive surgery had much higher odds of death 1 year after being diagnosed with cancer. In total, 69% of the PCTs were below the lower control limit of surgery and have predicted random intercepts above the mean value of zero of the random effect for mortality, whereas 40% were above the upper control limit of mortality within 1 year. CONCLUSIONS: Our main results suggest the presence of clear geographical variation in the use of surgical treatment of NSCLC and mortality. Mixed-effects models combined with the funnel plot approach were useful for assessing the performance of PCTs that were above average in mortality and below average in surgery.


Subject(s)
Carcinoma, Non-Small-Cell Lung/mortality , Healthcare Disparities/statistics & numerical data , Lung Neoplasms/mortality , Primary Health Care/statistics & numerical data , Surgical Procedures, Operative/statistics & numerical data , Treatment Outcome , Adolescent , Adult , Age Distribution , Aged , Aged, 80 and over , Carcinoma, Non-Small-Cell Lung/economics , Carcinoma, Non-Small-Cell Lung/surgery , England/epidemiology , Female , Geography , Healthcare Disparities/economics , Humans , Incidence , Logistic Models , Lung Neoplasms/economics , Lung Neoplasms/surgery , Male , Middle Aged , Poverty Areas , Primary Health Care/economics , Primary Health Care/methods , Registries , Sex Distribution , Surgical Procedures, Operative/economics , Survival Analysis , Young Adult
19.
Lancet ; 385(9974): 1206-18, 2015 Mar 28.
Article in English | MEDLINE | ID: mdl-25479696

ABSTRACT

BACKGROUND: Assessment of progress in cancer control at the population level is increasingly important. Population-based survival trends provide a key insight into the overall effectiveness of the health system, alongside trends in incidence and mortality. For this purpose, we aimed to provide a unique measure of cancer survival. METHODS: In this observational study, we analysed trends in survival with population-based data for 7·2 million adults diagnosed with a first, primary, invasive malignancy in England and Wales during 1971-2011 and followed up to the end of 2012. We constructed a survival index for all cancers combined using data from the National Cancer Registry and the Welsh Cancer Intelligence and Surveillance Unit. The index is designed to be independent of changes in the age distribution of patients with cancer and of changes in the proportion of lethal cancers in each sex. We analysed trends in the cancer survival index at 1, 5, and 10 years after diagnosis for the selected periods 1971-72, 1980-81, 1990-91, 2000-01, 2005-06, and 2010-11. We also estimated trends in age-sex-adjusted survival for each cancer. We define the difference in net survival between the oldest (75-99 years) and youngest (15-44 years) patients as the age gap in survival. We evaluated the absolute change (%) in the age gap since 1971. FINDINGS: The overall index of net survival increased substantially during the 40-year period 1971-2011, both in England and in Wales. For patients diagnosed in 1971-72, the index of net survival was 50% at 1 year after diagnosis. 40 years later, the same value of 50% was predicted at 10 years after diagnosis. The average 10% survival advantage for women persisted throughout this period. Predicted 10-year net survival adjusted for age and sex for patients diagnosed between 2010 and 2011 ranged from 1·1% for pancreatic cancer to 98·2% for testicular cancer. Net survival for the oldest patients (75-99 years) was persistently lower than for the youngest (15-44 years), even after adjustment for the much higher mortality from causes other than cancer in elderly people. INTERPRETATION: These findings support substantial increases in both short-term and long-term net survival from all cancers combined in both England and Wales. The net survival index provides a convenient, single number that summarises the overall patterns of cancer survival in any one population, in each calendar period, for young and old men and women and for a wide range of cancers with very disparate survival. The persistent sex difference is partly due to a more favourable cancer distribution in women than men. The very wide differences in survival for different cancers, and the persistent age gap in survival, suggest the need for renewed efforts to improve cancer outcomes. Future monitoring of the cancer survival index will not be possible unless the current crisis of public concern about sharing of individual data for public health research can be resolved. FUNDING: Cancer Research UK.


Subject(s)
Neoplasms/mortality , Adolescent , Adult , Age Distribution , Aged , Aged, 80 and over , England/epidemiology , Female , Humans , Incidence , Male , Mortality/trends , Registries , Sex Distribution , Survival Analysis , Wales/epidemiology , Young Adult
20.
Work ; 41 Suppl 1: 1124-31, 2012.
Article in English | MEDLINE | ID: mdl-22316870

ABSTRACT

This article is result from a questionnaire about mobile app store usage. The objective of this work was to collect information about user needs and opinion regarding search, purchase and evaluation process in Android Market, Apple App Store, BlackBerry App World and Nokia Ovi Store. The data collected was analyzed to identify the positive and negative usability aspects, if the process to perform these task are any different in those stores and if the users are satisfy with their store or if they have any complains about it. Its covers the brazilian market only.


Subject(s)
Consumer Behavior , Information Storage and Retrieval , Mobile Applications , User-Computer Interface , Adult , Brazil , Cell Phone , Commerce , Demography , Female , Humans , Information Seeking Behavior , Male , Surveys and Questionnaires , Young Adult
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