Realising opportunities for evidence-based cancer service delivery and research: linking cancer registry and administrative data in Australia

Innovative use of Australian cancer registry data for early detection of the effects of epidemics and other mass disruptions on cancer incidence

BACKGROUND

Predictive modelling using pre-epidemic data have long been used to guide public health responses to communicable disease outbreaks and other health disruptions. In this study, cancer registry and related health data available 2-3 months from diagnosis were used to predict changes in cancer detection that otherwise would not have been identified until full registry processing was completed about 18-24 months later. A key question was whether these earlier data could be used to predict cancer incidence ahead of full processing by the cancer registry as a guide to more timely health responses. The setting was the Australian State of New South Wales, covering 31 % of the Australian population. The study year was 2020, the year of emergence of the COVID-19 pandemic.

METHODS

Cancer detection in 2020 was modelled using data available 2-3 months after diagnosis. This was compared with data from full registry processing available from 2022. Data from pre-pandemic 2018 were used for exploratory model building. Models were tested using pre-pandemic 2019 data. Candidate predictor variables included pathology, surgery and radiation therapy reports, numbers of breast screens, colonoscopies, PSA tests, and melanoma excisions recorded by the universal Medical Benefits Schedule (MBS). Data were analysed for all cancers collectively and 5 leading types.

RESULTS

Compared with full registry processing, modelled data for 2020 had a >95 % accuracy overall, indicating key points of inflexion of cancer detection over the COVID-disrupted 2020 period. These findings highlight the potential of predictive modelling of cancer-related data soon after diagnosis to reveal changes in cancer detection during epidemics and other health disruptions.

CONCLUSIONS

Data available 2-3 months from diagnosis in the pandemic year indicated changes in cancer detection that were ultimately confirmed by fully-processed cancer registry data about 24 months later. This indicates the potential utility of using these early data in an early-warning system.

Collecting routine and timely cancer stage at diagnosis by implementing a cancer staging tiered framework: the Western Australian Cancer Registry experience

BACKGROUND

Current processes collecting cancer stage data in population-based cancer registries (PBCRs) lack standardisation, resulting in difficulty utilising diverse data sources and incomplete, low-quality data. Implementing a cancer staging tiered framework aims to improve stage collection and facilitate inter-PBCR benchmarking.

OBJECTIVE

Demonstrate the application of a cancer staging tiered framework in the Western Australian Cancer Staging Project to establish a standardised method for collecting cancer stage at diagnosis data in PBCRs.

METHODS

The tiered framework, developed in collaboration with a Project Advisory Group and applied to breast, colorectal, and melanoma cancers, provides business rules - procedures for stage collection. Tier 1 represents the highest staging level, involving complete American Joint Committee on Cancer (AJCC) tumour-node-metastasis (TNM) data collection and other critical staging information. Tier 2 (registry-derived stage) relies on supplementary data, including hospital admission data, to make assumptions based on data availability. Tier 3 (pathology stage) solely uses pathology reports.

FINDINGS

The tiered framework promotes flexible utilisation of staging data, recognising various levels of data completeness. Tier 1 is suitable for all purposes, including clinical and epidemiological applications. Tiers 2 and 3 are recommended for epidemiological analysis alone. Lower tiers provide valuable insights into disease patterns, risk factors, and overall disease burden for public health planning and policy decisions. Capture of staging at each tier depends on data availability, with potential shifts to higher tiers as new data sources are acquired.

CONCLUSIONS

The tiered framework offers a dynamic approach for PBCRs to record stage at diagnosis, promoting consistency in population-level staging data and enabling practical use for benchmarking across jurisdictions, public health planning, policy development, epidemiological analyses, and assessing cancer outcomes. Evolution with staging classifications and data variable changes will futureproof the tiered framework. Its adaptability fosters continuous refinement of data collection processes and encourages improvements in data quality.

Cancer incidence and outcomes registries in an Australian context: a systematic review

BACKGROUND

Multiple cancer registries in Australia are used to track the incidence of cancer and the outcomes of their treatment. These registries can be broadly classed into a few types with an increasing number of registries comes a greater potential for collaboration and linkage. This article aims to critically review cancer registry types in Australia and evaluate the Australian Cancer registry landscape to identify these areas.

METHODS

A systematic review was performed through MEDLINE, EMBASE and Cochrane Library, updated to September 2022 using a predefined search strategy. Inclusion criteria were those that only analysed Australian and/or New Zealand based cancer registries, appraised the utility of cancer outcomes and/or incidence registries, and explored the utility of linked databases using cancer outcomes and/or incidence registries. The grey literature was searched for all operating cancer registries in Australia. Details of registry infrastructure was extracted for analysis and comparison.

RESULTS

Three thousand two hundred and sixteen articles identified from the three databases. Twelve met the inclusion criteria. Twenty-eight registries were identified using the grey literature. Strengths and weaknesses of Cancer Outcome Registries(COR) and Cancer Incidence Registries(CIR) were compared. Data linkage between registries or with other healthcare databases show great benefits in improving evidence for cancer research but are challenging to implement. Both registry types utilize differing modes of administration, influencing their accuracy and completeness.

CONCLUSION

Outcome registries provide detailed data but their weakness lies in incomplete data coverage. Incidence registries record a large dataset which contain inaccuracies. Improving coverage of quality outcome registries, and quality assurance of data in incidence registries is required to ensure collection of accurate, meaningful data. Areas for collaboration identified included establishment of defined definitions and outcomes, data linkage between registry types or with healthcare databases, and collaboration in logistical planning to improve clinical utility of cancer registries.

Occurrence and timely management of problems requiring prompt intervention among Indigenous compared with non-Indigenous Australian palliative care patients: a multijurisdictional cohort study

OBJECTIVES

Anticipation and prompt relief of symptoms among patients with a life-limiting illness is a core element of palliative care. Indigenous Australians commonly encounter cultural barriers in healthcare that may impair outcomes. The Palliative Care Outcomes Collaboration collects patient care data for the purposes of continuous quality improvement and benchmarking, with each recorded care episode divided into phases that reflect a patient's condition. We aimed to investigate differences between Indigenous and non-Indigenous patients in the occurrence and duration of 'unstable' phases (which indicate unanticipated deterioration in a patient's condition or circumstances), and determine attainment of the relevant benchmark (resolution of unstable phases in ≤3 days in 90% of cases) for both groups.

DESIGN

Cohort study.

SETTING

Australia-wide hospital-based and community-based specialist palliative care (1 January 2010 to 30 June 2015).

PARTICIPANTS

139 556 (1502 Indigenous and 138 054 non-Indigenous) adult patients.

OUTCOME MEASURES

Indigenous and non-Indigenous patients were compared on (1) the risk of a phase being categorised as unstable, (2) the duration of unstable phases, and (3) the risk of unstable phases being prolonged (>3 days). Crude and adjusted estimates were produced from three-level robust Poisson regression and complementary log-log discrete time survival models.

RESULTS

Unstable phases occurred with similar frequency overall among Indigenous and non-Indigenous patients (adjusted relative risks 1.06; 95% CI 1.00 to 1.11; not significant after correction for multiple comparisons). The duration and risk of prolongation of unstable phases were similar in both patient groups, with no significant differences evident among subgroups. The benchmark was not met for either Indigenous or non-Indigenous patients (unstable phase duration >3 days in 24.3% vs 25.5%; p=0.398).

CONCLUSIONS

Despite well-documented shortcomings of healthcare for Indigenous Australians, there is no clear evidence of greater occurrence or prolongation of unanticipated problems among Indigenous patients accessing specialist palliative care services in hospital or the community.

Augmenting cancer registry data with health survey data with no cases in common: the relationship between pre-diagnosis health behaviour and post-diagnosis survival in oesophageal cancer

Background

For epidemiological research, cancer registry datasets often need to be augmented with additional data. Data linkage is not feasible when there are no cases in common between data sets. We present a novel approach to augmenting cancer registry data by imputing pre-diagnosis health behaviour and estimating its relationship with post-diagnosis survival time.

Methods

Six measures of pre-diagnosis health behaviours (focussing on tobacco smoking, ‘at risk’ alcohol consumption, overweight and exercise) were imputed for 28,000 cancer registry data records of US oesophageal cancers using cold deck imputation from an unrelated health behaviour dataset. Each data point was imputed twice. This calibration allowed us to estimate the misclassification rate. We applied statistical correction for the misclassification to estimate the relative risk of dying within 1 year of diagnosis for each of the imputed behaviour variables. Subgroup analyses were conducted for adenocarcinoma and squamous cell carcinoma separately.

Results

Simulated survival data confirmed that accurate estimates of true relative risks could be retrieved for health behaviours with greater than 5% prevalence, although confidence intervals were wide. Applied to real datasets, the estimated relative risks were largely consistent with current knowledge. For example, tobacco smoking status 5 years prior to diagnosis was associated with an increased age-adjusted risk of all cause death within 1 year of diagnosis for oesophageal squamous cell carcinoma (RR = 1.99 95% CI 1.24,3.12) but not oesophageal adenocarcinoma RR = 1.61, 95% CI 0.79,2.57).

Conclusions

We have demonstrated a novel imputation-based algorithm for augmenting cancer registry data for epidemiological research which can be used when there are no cases in common between data sets. The algorithm allows investigation of research questions which could not be addressed through direct data linkage.

Growth of linked hospital data use in Australia: a systematic review

Objective The aim of the present study was to quantify and understand the utilisation of linked hospital data for research purposes across Australia over the past two decades. Methods A systematic review was undertaken guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 checklist. Medline OVID, PsycINFO, Embase, EconLit and Scopus were searched to identify articles published from 1946 to December 2014. Information on publication year, state(s) involved, type of data linkage, disease area and purpose was extracted. Results The search identified 3314 articles, of which 606 were included; these generated 629 records of hospital data linkage use across all Australian states and territories. The major contributions were from Western Australia (WA; 51%) and New South Wales (NSW; 32%) with the remaining states and territories having significantly fewer publications (total contribution only 17%). WA's contribution resulted from a steady increase from the late 1990s, whereas NSW's contribution is mostly from a rapid increase from 2010. Current data linkage is primarily used in epidemiological research (73%). Conclusion More than 80% of publications were from WA and NSW, whereas other states significantly lag behind. The observable growth in these two states clearly demonstrates the underutilised opportunities for data linkage to add value in health services research in the other states. What is known about the topic? Linking administrative hospital data to other data has the potential to be a cost-effective method to significantly improve health policy. Over the past two decades, Australia has made significant investments in improving its data linkage capabilities. However, several articles have highlighted the many barriers involved in using linked hospital data. What does this paper add? This paper quantitatively evaluates the performance across all Australian states in terms of the use of their administrative hospital data for research purposes. The performance of states varies considerably, with WA and NSW the clear stand-out performers and limited outputs currently seen for the other Australian states and territories. What are the implications for practitioners? Given the significant investments made into data linkage, it is important to continue to evaluate and monitor the performance of the states in terms of translating this investment into outputs. Where the outputs do not match the investment, it is important to identify and overcome those barriers limiting the gains from this investment. More generally, there is a need to think about how we improve the effective and efficient use of data linkage investments in Australia.

Exploring the added value of hospital-registry data for showing local service outcomes: cancers of the ovary, fallopian tube and peritoneum

OBJECTIVES

To explore the added value of hospital-registry data on invasive epithelial ovarian, tubal and peritoneal cancers.

DESIGN

Historic cohort analyses.

METHODS

Unadjusted and adjusted regression.

SETTING

Major South Australian hospitals.

PARTICIPANTS

1596 women (1984-2015 diagnoses).

RESULTS

5-Year and 10-year survival was 48% and 41%, respectively, equivalent to relative survival for Australia and the USA. After adjusting for age, clinical and geographic factors, risk of ovarian cancer death was 25% lower in 2010-2015 than 1984-1989. Women generally had surgical treatment (87%) in their first round of care. This was more common for younger patients (adjusted OR (95% CIs) 0.17 (0.04 to 0.65) for 80+ vs <40 years) and earlier International Federation of Gynecology and Obstetrics stages (adjusted OR 0.48 (0.13 to 1.78) for stage IIIB/C and 0.13 (0.04 to 0.45) for stage IV vs stage IA). Most (74%) had systemic therapy, which was more common for advanced stages (adjusted ORs >15.0 for stages III and IV vs stage IA). Few (9%) had radiotherapy. Women generally had systemic therapy (74%), without difference by service accessibility and socioeconomic disadvantage, suggesting equity. However, surgery was less common for residents of the most compared with least remote areas (adjusted OR 0.49 (0.24 to 0.99)); and more common prior to adjustment in the highest versus lowest socioeconomic category (unadjusted OR 1.55 (1.01 to 2.39)), but this elevation did not apply after adjustment (adjusted OR 0.19 (0.63 to 2.25)), with the difference largely explained by stage.

CONCLUSIONS

Hospital-registry data add value for assessing local service delivery. Equivalent survival to Australia-wide and USA survival, and temporal gains after adjusting for stage and other patient characteristics are reassuring. Survival gains may reflect therapeutic benefits of more extensive surgery and improved chemotherapy regimens.

Breast cancer screening-opportunistic use of registry and linked screening data for local evaluation

RATIONALE

Screening has been found to reduce breast cancer mortality at a population level in Australia, but these studies did not address local settings where numbers of deaths would generally have been too low for evaluation. Clinicians, administrators, and consumer groups are also interested in local service outcomes. We therefore use more common prognostic and treatment measures and survivals to gain evidence of screening effects among patients attending 4 local hospitals for treatment.

AIMS AND OBJECTIVES

To compare prognostic, treatment, and survival measures by screening history to determine whether expected screening effects are occurring.

METHODS

Employing routine clinical registry and linked screening data to investigate associations of screening history with these measures, using unadjusted and adjusted analyses.

RESULTS

Screened women had a 10-year survival from breast cancer of 92%, compared with 78% for unscreened women; and 79% of screened surgical cases had breast conserving surgery compared with 64% in unscreened women. Unadjusted analyses indicated that recently screened cases had earlier tumor node metastasis stages, smaller diameters, less nodal involvement, better tumor differentiation, more oestrogen and progesterone receptor positive lesions, more hormone therapy, and less chemotherapy. Radiotherapy tended to be more common in screening participants. More frequent use of adjunctive radiotherapy applied when breast conserving surgery was used.

CONCLUSIONS

Results confirm the screening effects expected from the scientific literature and demonstrate the value of opportunistic use of available registry and linked screening data for indicating to local health administrations, practitioners, and consumers whether local screening services are having the effects expected.

Hospital admissions in children with cerebral palsy: a data linkage study

AIM

The overall aim was to investigate the feasibility and utility of linking a cerebral palsy (CP) register to an administrative data set for health services research purposes. We sought to compare CP hospital admissions to general childhood population admissions, and identify factors associated with type and frequency of admissions in a CP cohort.

METHOD

The CP register for Victoria, Australia was linked to the state's hospital admissions database. Data pertaining to the admissions of a CP cohort (n=1748) that took place between 2007 and 2014 were extracted. Population data were also obtained.

RESULTS

Overall, 80% of the CP cohort (n=1401) had at least admission between 2007 and 2014, accounting for 11 012 admissions or 1.5% of all admissions in their age group. Compared to general population admissions, CP admissions were more costly and more likely to be elective (66% vs 57%; p<0.001), medical (71% vs 57%; p<0.001), and to take place in metropolitan hospitals (92% vs 78%; p<0.001). Increased CP severity and complexity were associated with having more admissions and a higher proportion of admissions attributable to respiratory illness.

INTERPRETATION

By linking with administrative data sets, CP registers may be useful for health services research and inform health service delivery.

Administrative data provide vital research evidence for maximizing health-system performance and outcomes

Although the quality of administrative data is frequently questioned, these data are vital for health-services evaluation and complement data from trials, other research studies and registries for research. Trials generally provide the strongest evidence of outcomes in research settings but results may not apply in many service environments. High-quality observational research has a complementary role where trials are not applicable and for assessing whether trial results apply to groups excluded from trials. Administrative data have a broader system-wide reach, enabling system-wide health-services research and monitoring of performance markers. Where administrative data raise questions about service outcomes, follow-up enquiry may be required to investigate validity and service implications. Greater use should be made of administrative data for system-wide monitoring and for research on service effectiveness and equity.

Metastatic Colorectal Cancer Treatment and Survival: the Experience of Major Public Hospitals in South Australia Over Three Decades

BACKGROUND

Registry data from four major public hospitals indicate trends over three decades from 1980 to 2010 in treatment and survival from colorectal cancer with distant metastases at diagnosis (TNM stage IV).

MATERIALS AND METHODS

Kaplan-Meier product-limit estimates and Cox proportional hazards models for investigating disease-specific survival and multiple logistic regression analyses for indicating first-round treatment trends.

RESULTS

Two-year survivals increased from 10% for 1980-84 to 35% for 2005-10 diagnoses. Corresponding increases in five-year survivals were from 3% to 16%. Time-to-event risk of colorectal cancer death approximately halved (hazards ratio: 0.48 (0.40, 0.59) after adjusting for demographic factors, tumour differentiation, and primary sub-site. Survivals were not found to differ by place of residence, suggesting reasonable equity in service provision. About 74% of cases were treated surgically and this proportion increased over time. Proportions having systemic therapy and/or radiotherapy increased from 12% in 1980-84 to 61% for 2005-10. Radiotherapy was more common for rectal than colonic cases (39% vs 7% in 2005-10). Of the cases diagnosed in 2005-10 when less than 70 years of age, the percentage having radiotherapy and/or systemic therapy was 79% for colorectal, 74% for colon and 86% for rectum (and RS)) cancers. Corresponding proportions having: systemic therapies were 75%, 71% and 81% respectively; radiotherapy were 24%, 10% and 46% respectively; and surgery were 75%, 78% and 71% respectively. Based on survey data on uptake of offered therapies, it is likely that of these younger cases, 85% would have been offered systemic treatment and among rectum (and RS) cases, about 63% would have been offered radiotherapy.

CONCLUSIONS

Pronounced increases in survivals from metastatic colorectal cancer have occurred, in keeping with improved systemic therapies and surgical interventions. Use of radiotherapy and/or systemic therapy has increased markedly and patterns of change accord with clinical guideline recommendations.

Colorectal cancer treatment and survival: the experience of major public hospitals in south Australia over three decades

BACKGROUND

Registry data from four major public hospitals indicate trends in clinical care and survival from colorectal cancer over three decades, from 1980 to 2010.

MATERIALS AND METHODS

Kaplan-Meier product- limit estimates and Cox proportional hazards models were used to investigate disease-specific survival and multiple logistic regression analyses to explore first-round treatment trends.

RESULTS

Five-year survivals increased from 48% for 1980-1986 to 63% for 2005-2010 diagnoses. Survival increases applied to each ACPS stage (Australian Clinico-Pathological Stage), and particularly stage C (an increase from 38% to 68%). Risk of death from colorectal cancer halved (hazards ratio: 0.50 (0.45, 0.56)) over the study period after adjusting for age, sex, stage, differentiation, primary sub-site, health administrative region, and measures of socioeconomic status and geographic remoteness. Decreases in stage were not observed. Survivals did not vary by sex or place of residence, suggesting reasonable equity in service access and outcomes. Of staged cases, 91% were treated surgically with lower surgical rates for older ages and more advanced stage. Proportions of surgical cases having adjuvant therapy during primary courses of treatment increased for all stages and were highest for stage C (an increase from 5% in 1980-1986 to 63% for 2005-2010). Radiotherapy was more common for rectal than colonic cases. Proportions of rectal cases receiving radiotherapy increased, particularly for stage C where the increase was from 8% in 1980-1986 to 60% in 2005-2010. The percentage of stage C colorectal cases less than 70 years of age having systemic therapy as part of their first treatment round increased from 3% in 1980-1986 to 81% by 1995-2010. Based on survey data on uptake of adjuvant therapy among those offered this care, it is likely that all these younger patients were offered systemic treatment.

CONCLUSIONS

We conclude that pronounced increases in survivals from colorectal cancer have occurred at major public hospitals in South Australia due to increases in stage-specific survivals. Use of adjuvant therapies has increased and the patterns of change accord with clinical guideline recommendations. Reasons for sub-optimal use of radiotherapy for rectal cases warrant further investigation, including the potential for limited rural access to impede uptake of treatments at metropolitan-based radiotherapy centres.