Using linked data for assessing patterns of cancer care

1. Using linked data for assessing patterns of cancer care Dianne O’Connell David Goldsbury POC Study Teams Cancer Epidemiology Research Unit Cancer Council, NSW

2. Overview • Patterns of cancer care studies • Use of linked records • Validation of linked data sets for patterns of care • Possible analyses of linked data sets • Other research using linked records

3. Patterns of Cancer Care Studies • Describe treatment patterns • Compare management with guidelines • Assess accessibility to care • Identify inequities in care

4. Methods • Ad hoc data collections • Clinical Cancer Registries • Record linkage of routinely collected (administrative) data sets

5. Patterns of cancer care studies • Lung, colorectal, prostate cancers in NSW • Methods • Identify patients through population-based NSW Central Cancer Registry (CCR) • Consent from doctors and patients to pass details on to researchers • Informed consent from patients

6. Patterns of care studies – methods • Questionnaires from treating doctors • Find correct doctor • Obtain treatment and referral information • Field collection where necessary • Response rates • colorectal 88-97% • lung 62% • prostate 64% • Participants diagnosed 1999-2002

7. Patterns of care studies - limitations • Resource intensive • Consent rates from patients • Response rates from doctors • Relies on doctors’ clinical notes • Data represents a snapshot and soon out of date

8. Is there an easier way? • Cancer registry information in Australia does not include treatment • Hospital discharge records will not capture or identify all relevant cases of cancer • Combined, they may be more useful

9. Use of administrative datasets (1) • NSW Central Cancer Registry (CCR) • Population-based • Cancer is notifiable due to Public Health Act • Hospitals, pathology labs, radiation oncologists, nursing homes, deaths

10. Use of administrative datasets (2) • NSW Admitted Patient Data Collection (APDC) • All hospital separations (discharges, transfers, deaths) • All NSW public and private hospitals and day procedure centres

11. Admitted Patient Data Collection July 1992 - Jun 2003 NSW Central Cancer Registry 1993 - 2002 Record linkage • Linked by NSW Health in 2005 • 86% of CCR cases linked to APDC • Procedures & comorbidities identified in APDC records

12. Variables • CCR • sex, age at diagnosis, health area and SLA of residence, date of diagnosis, best method of diagnosis, spread of disease at diagnosis, cause of death (if dead), survival time • APDC • sex, age, health area and SLA of residence, health area of treatment, type of hospital, date of admission, date of separation, procedures, principal diagnosis, additional diagnoses, health insurance status on admission

13. Analysis issues • One record per hospital episode, each with multiple procedure/diagnosis codes • Assign relevant formats, SES and accessibility/remoteness categories • Identify procedure/diagnosis codes for each type of treatment • Summarise!

14. Validation of CCR-APDC data • Cancer Council patient surveys were linked to CCR-APDC data set • Linked, routinely collected data validated at individual patient level • Usefulness of these data for patterns of cancer care studies assessed

15. Validation data Prostate, colorectal and lung cases for linkage (n=7425) No CCR link (n=206) Link to CCR (n=7219) No survey treatment info (n=576) Survey treatment info (n=6643) No APDC link (n=516) Link to APDC (n=6127)

16. Validation data • Overall: 6127 cases with data from patient surveys and administrative records • Prostate: 1591 cases • Lung: 1580 cases • Colorectal: 2956 cases

17. Validity of surgical data

18. Surgery records missed • Extra cases in admin data: 2 for prostate, 15 for lung

19. Validity of chemotherapy data N/A • Generally an outpatient procedure, no admission recorded

20. Validity of radiotherapy data • As with chemotherapy, often an outpatient procedure with no admission

21. Prostate radiotherapy data • Brachytherapy involves general anaesthetic, often a hospital admission

22. Investigations: Lung

23. Investigations: Colorectal

24. Validation conclusions • Linked routinely collected data useful for: • Major surgical procedures • Other inpatient procedures (e.g. brachytherapy) • Complementary data sources required for: • Chemotherapy • Radiotherapy • Investigative procedures • Comorbidities • Medicare Australia information to improve data coverage • MBS: referrals, diagnostic and therapeutic procedures • PBS: medicines

25. What else can we analyse using these CCR-APDC data? • Treatment trends over time • Time from diagnosis to treatment • Distance travelled for treatment (approx.) • Changed address at treatment • Factors associated with treatment • Rural/urban, socioeconomic, age, insurance • Survival after treatment

26. Patterns of surgical care for prostate cancer in NSW, 1993-2002: rural/urban and socio-economic variation Andrew Hayen et al ANZ J Pub Health 2008;32:417-420

27. Radical prostatectomies in NSW

28. Radical prostatectomy * Adjusted for age, spread of disease and year of diagnosis

29. Time from diagnosis to treatment Time to surgery for lung cancer Using month of diagnosis from CCR

30. CCR-APDC dataset - advantages • Availability of data • Relatively cheap • Includes large numbers of individuals • Ongoing data collection – monitoring

31. CCR-APDC dataset - limitations • Incomplete coverage of chemotherapy and radiotherapy • Doesn’t cover pathways to diagnosis and referral patterns or outcomes • Lack of disease clinical detail (NSW – crude disease staging) • Incomplete matching – no hospital record  no treatment • Cross-border patient flows

32. Other research with linked records • Descriptive patterns of care studies for other cancer types • Medicare and pharmaceutical benefits data to improve treatment coverage • Colorectal cancer referral pathways study • Survival follow-up analysis for previous POC studies • Hepatitis B and C linked with Cancer Registry (National Centre in HIV Epidemiology and Clinical Research) • Cancer Registry linked to Midwives Data Collection (Cancer Institute NSW)