The Scottish electronic diabetes register and cancer registry and their linkage Sarah Wild, University of Edinburgh Thanks to David Brewster, Director of the Scottish Cancer Registry June 2010

Background - Scotland Population approximately 5.1 million people, 14 Health Boards Health data identified using Community Health Index which is used for routine linkage of hospital admissions, cancer registrations and mortality records Prescribing data available from primary care records – encashment data from pharmacies available soon

Background – diabetes register Scottish Care Information – Diabetes Collaboration (SCI-DC) is an electronic population-based diabetes register populated by daily downloads from primary and secondary care systems, including prescribing Data collection started in Tayside and Lanarkshire with national data collected from 2000 onwards Core data set includes demographic and relevant clinical data – completeness >95% (except ethnicity) Access for research through Scottish Diabetes Research Network (SDRN) epidemiology group

Number of people included in the Scottish electronic diabetes register Source: Scottish Diabetes Survey 2009

2008 data extract Data available for approx 270,000 people Based on people with data on age, sex and SIMD recorded on SCI-DC who were alive in April 2008 (approx. 204,000 of 209,000) there were: 26,242 people with T1DM (crude prevalence 0.51%) 177,783 people with T2DM (crude prevalence 3.46%) GROS 2008 population estimates used for denominator

Validation of recorded type 1 diabetes and prevalence

Age and sex standardised prevalence of type 2 diabetes by Scottish Index of Multiple Deprivation quintile

Background – cancer registry Cancer data collected since 1958 with full dataset including stage, (for breast, colorectal and cervical cancer) and information on treatment for all patients collected from 1997 Approx. 40,000 registrations/ year Total of over 1,200,000 records Data quality monitored using routine indicators, computer validation, data exchange with specialist tumour registries and ad hoc studies of data accuracy and completeness of ascertainment.

Collection of Scottish Cancer Registry data Electronic capture and reformatting of ‘raw’ data Probability matching to related incoming records and to previous registrations Application of multiple primary rules and rules to deal with metastatic disease Creation of ‘best guess’ provisional registrations Completion and validation by staff based in hospitals using medical records at least 6 months after date of diagnosis

Source data Hospital discharge records Radiotherapy, oncology, haematology Pathology records (8 different lab systems) Mortality records Cancer audit data (not for all cancers) Other, eg paper records from private hospitals Deaths from General Register Office for Scotland

Invasive cancer of the cervix uteri in Scotland Age-standardised incidence and mortality rates per 100,000 person-years at risk by SIMD 2006 category

Oesophageal adenocarcinoma in UK women: results of a case-control study Source: Cheng et al. Br J Cancer 2000; 83: VariableAdjusted OR (95% CIs)P for trend BMI at age 20 Q1 <19.49 Q Q Q4 > ( ) 4.90 ( ) 6.04 ( )0.002 Total fruit consumption (per week) Q1 <12.00 Q Q Q4 > ( ) 0.37 ( ) 0.08 ( )0.002 Breastfeeding No children Had children but never breast fed Up to 6 months >6 months ( ) 0.30 ( ) 0.13 ( )0.005

Factors influencing population-based survival data Data quality factorsTumour-related factors Completeness of ascertainmentExtent of disease Accuracy of registrationSite (and subsite) of tumour Completeness of follow-upMorphology ‘Death certificate only’ registrationsTumour biology Host factorsHealth care-related factors AgeScreening SexDiagnostic facilities Race/EthnicityTreatment facilities Co-morbidityQuality of treatment Socio-economic statusFollow-up care Behaviour (including awareness of cancer symptoms and compliance with treatment)

Linkage pilot (2005 data, 2 Health Boards): validation of diabetes recording 47% of 82,958 hospital records after a diagnosis of diabetes include a mention of diabetes (71% of SMR01 records for MI after diagnosis of diabetes) Of the 4,777 death certificates, 9.6% gave diabetes as the underlying cause of death and a further 39% mentioned diabetes as a contributory cause

Background to linkage project The Scottish Government Health Department funded the linkage of 2008 SCI-DC data to cancer (2007) and hospital admission/mortality (2008) data. Ethical and Caldicott guardian approval obtained Early work based on improving quality of data on date of diagnosis, type of diabetes, prescribing data, glargine & cancer Further linkages to renal register, maternity records, hepatitis C register

Characteristics by treatment group Characteristic Data presented as Non-glargine insulin Non-glargine plus glargine insulin Insulin glargine onlyp value a Subjects % (n)92.7 (18,455)5.2 (1,033)2.1 (411) Sex, % women % (n)48.8 (8,996)48.5 (501)52.6 (216)0.13 Age, years median (LQ, UQ)65 (56,72)57 (49, 66)69 (59,77)< BMI, kg / m 2 mean (SD)30.4 (6.1)27.9 (5.7)30.1 (6.2)< Systolic BP, mmHg mean (SD) (22)136.1 (19.5)140.5(20.5)0.19 Diastolic BP, mmHg mean (SD)76 (12)77 (12)77(13)0.006 HbA 1c, % mean (SD)8.5 (1.7)9.0 (1.7)9.3 (1.8)< Duration of diabetes  5 years % (n)83.2 (15,360)76.8 (793)75.2 (309)< Prior Insulin  5years on insulin % (n)37.2 (6,867)47.1 (487)4.6 (19)< Age at diagnosis, years median534659< Prior cancer Ever % (n)7.4 (1,357)5.0 (52)9.3 (38)0.59  5 years ago % (n)3.6 (664)2.7 (28)5.6 (23)0.35 Any CVD % (n)18.6 (3,441)12.1 (125)22.1 (91)0.016 Ever smoked % (n)29.9 (4,335)28.4 (247)24.8 (77)0.001 Use of oral glucose-lowering drugs at baseline b % (n)28.9(4559)23.4 (169)80.0 (295)< On three or more oral glucose- lowering drugs at baseline % (n)4.0 (745)3.1 (32)29.4 (121)< In the two most deprived SIMD quintiles % (n)47.1 (8,686)35.4 (366)54.0 (222)<0.0001

a Model 1 adjusts for prior cancer, type of diabetes and calendar year, and is stratified by sex ; timescale is age b Model 2 further adjusts for baseline metformin, sulfonylurea and other oral hypoglycaemic drugs at baseline c Model 3 further adjusts for diabetes duration, HbA 1c, diastolic BP, systolic BP and deprivation quintile d Model 4 further adjusts for smoking ever and BMI, but note the reduction in available sample size Risk of cancer by treatment group

Cancer registrations and deaths in 2008 Scottish diabetes linked data YearRegistrationsDeaths Only includes first registration of each cancer in an individual person. Includes ICD-9 codes EXCEPT 173; ICD-10 codes C00-C97 EXCEPT C44

Distribution of cancer registrations by type/date of diagnosis of diabetes Type1Type 2 Cancer prior to diagnosis of DM Cancer after diagnosis of DM Date diagnosis of DM unknown 50730

Number of site specific cancers following diagnosis of DM Type 1Type 2 Colo-rectal Lung Breast Prostate Pancreas86812 Endometrial38689 Liver48565

Acknowledgements SCI-DC data are available for analysis by members of the Scottish Diabetes Research Network thanks to the hard work of numerous NHS staff who enter the data and people and organisations (the Scottish Care Information –Diabetes Collaboration [SCI-DC] Steering Group, the Scottish Diabetes Group, the Scottish Diabetes Survey Group, the managed clinical networks managers and staff in each Health Board) involved in setting up, maintaining and overseeing SCI-DC. Financial support for the work was provided by the Scottish Government and the Wellcome Trust through the Scottish Health Informatics Programme