Cohort Descriptives

Variable Response
Cohort Name The Secure Anonymised Information Linkage Databank Dementia e-Cohort
Cohort Acronym SAIL-DeC
DOI Wilkinson , T. (2017). SAIL-DeC [Data set]. Dementias Platform UK.
Study Overview SAIL-DeC is a nationwide dementia electronic cohort for Wales created from a cohort of participants of the SAIL Databank for whom primary care data were available. The SAIL Databank (4,389,213 participants, approximately 80% of the Welsh population and representative of the wider population), contains anonymised, individual-level, linked routinely-collected health and social care information including primary care (General Practitioner), hospital admissions, mortality and demographic data as well as a population spine that allows for linkage across multiple health datasets. The SAIL-DeC cohort consists of people born between 1st January 1900 and 1st January 1958. The database consists of administrative data so does not require the usual participant consent. SAIL-DeC was contructed using the linked primary care, hospital admissions and mortality and deprivation datasets. A validated algorithmn applied ICD-9, ICD-10 and Read V2 codes to identify cases of all-cause dementia and dementia sub-types in the primary and secondary care and mortality data. Derived variables were created for comorbidities and risk factors. This virtual ‘electronic-cohort’ for dementia research organises and simplifes the complex SAIL dataset thus reducing the work time and costs. The intention is also for it to be flexibility and reproducible meaning researchers can use the resource to answer a wide range of longitudinal dementia-related questions. SAIL-DeC will be maintained and updated over time, as newer data become available.
#Subjects at Baseline 1,246,557 in the initial cohort.
Institution Name Swansea University, University of Edinburgh
Department Name (Swansea: Health Data Research UK Wales and Northern Ireland, Edinburgh: Usher Institite of Population Health Sciences and Informatics
City Across Wales
Study/Database Website

Principal Investigator (PI) Dr Tim Wilkinson (University of Edinburgh)
Key Study References

Please see publications section

Population Based Study? Yes
Family Based Study? No
Clinical based sample? No
Is there follow-up data available? Not yet
Were participants included prior to development of dementia (may refer to controls only)? Yes
Were participants included prior to development of MCI (may refer to controls only)? Yes
How is data collected? By Algorithmn applied to the SAIL Databank, a privacy protecting safe haven
Who carries out data collection? SAIL-DeC data research, from SAIL Databank collected data
Does this take place in participants' homes or at a central location? Central
Do participants take part individually or are families/partners involved? Individually
Dementia cases ascertained as part of study: Yes, a validated algorithm identifies all-cause dementia cases from coded primary care, hospital admission and mortality datasets
Diagnosis based on review of existing clinical data No
Was diagnosis/primary outcomes made blind to exposure variables? No
How many times followed up? 0
# Subjects at Follow-up
Study start date 20/08/2018 00:00:00
Study end date
Is study ongoing? Yes
Is study still recruiting?
Inclusion criteria All participants in the SAIL databank with Primary Care data available based on being registered with a SAIL contributing General Practice at any point and born between 1st January 1900 and 1st January 1958, currently alive or recorded date of death on or between 1st January 1980 and 1st January 2020.
Exclusion criteria No valid GP registration start or end date, recorded date of birth before 1st January 1900, or date of death recorded as either before 1st January 1980 or after 1st January 2020. Patients who had a dementia diagnosis without a valid date i.e. before 1st January 1900 or after 1st January 2018.


Variable type
Participant ID
Month/Year of birth
Date aged 60
Date of Death
Start Date - registration with GP
End Date - deregistration with GP or death


Sub-category Variable type Baseline
Deprivation Latest WIMD (Welsh Index of Multiple Deprivation) Quintile (2011) Y
Deprivation Latest WDSD (Welsh Demographic Service Dataset) (2018) Y
Deprivation Census Reporting Zone- Lower Layer Super Output Areas (LSOAs) (2001) Y

Physical Health Status

Sub-category Variable type Baseline
Cancer Cancer type Y
Cardiothoracic Atrial Fibrillation types Y
Cardiothoracic Heart Failure types Y
Cardiothoracic Essential Hypertension Y
Cardiothoracic Hypertensive heart disease Y
Cardiothoracic Secondary hypertension Y
Cardiothoracic Myocardial infarction types Y
Cardiothoracic Peripheral vascular disease Y
Cardiothoracic Other peripheral vascular disease Y
Cardiothoracic Alcoholic cardiomyopathy Y
Cardiothoracic Rheumatoid arthritis myocarditis Y
Cerebrovascular Ischaemic stroke -Cerebral infarction Y
Cerebrovascular Ischaemic stroke-Subarachnoid haemorrhage Y
Cerebrovascular Ischaemic stroke-Intracerebral haemorrhage Y
Cerebrovascular Stroke not specified as haemorrhage or infarction Y
Cerebrovascular Chronic alcoholic brain syndrome/cerebral degeneration Y
Endocrinology Hypothyroidism types Y
Endocrinology Alcohol-induced pseudo-Cushing syndrome Y
ENT Leukokeratosis nicotina palati Y
Gastrointestinal Alcoholic liver disease types Y
Gastrointestinal Alcoholic pancreas disease types Y
General Health Diabetes Y
General Health Obesity Y
General Health Childhood obesity Y
Nephrology Chronic Kidney Disease (Stage III-IV e) Y
Neurological Epilepsy Y
Neurological Alcohol withdrawal-induced seizure Y
Neurological Motor Neurone disease types Y
Neurological Spinal muscular atropy Y
Neurological Anterior horn cell disease Y
Neurological Degeneration of cerebral or nervous system due to alcohol Y
Neurological Alcoholic myopathy Y
Pain Intermittent claudication Y
Pain Polyneuropathy in rheumatoid arthritis Y
Pain Alcoholic polyneuropathy Y
Respiratory Asthma severity Y
Respiratory Allergic Asthma triggers Y
Respiratory Absent from work or school due to asthma Y
Respiratory Asthma Day/night symptoms/disturbs sleep Y
Respiratory COPD Y
Respiratory COPD impacts sleep or not Y
Respiratory Emphysema Type Y
Respiratory MacLeod syndrome Y
Respiratory Obstructive chronic bronchitis Y
Respiratory Other chronic obstructive pulmonary disease Y
Respiratory Extreme obesity with alveolar hypoventilation Y
Respiratory Pickwickian syndrome Y
Rheumatology Rheumatoid Arthritis types Y
Rheumatology Osteoporosis types Y

Healthcare Utilisation

Sub-category Variable type Baseline
Hospitalisation Emergency asthma admission Y
Hospitalisation Drug dependence Y
Hospitalisation Mental and behavioural disorders due to use of various substances Y
Hospitalisation Mental and behavioural disorders due to use of alcohol Y
Hospitalisation Poisoning by Substances Y
Primary Care Asthma Assessment Y
Primary Care Asthma control questionnaire Y
Primary Care COPD Health education /clinical mangement plan Y
Primary Care COPD Review /follow-up /monitoring Y
Primary Care Advised to contact primary care alcohol worker Y
Primary Care Alcohol abuse monitoring Y
Primary Care Smoking cessation service Y
Primary Care Intervention for risk to health associated with overweight and obesity, general advice on healthy weight and lifestyle Y
Primary Care Dietary surveillance and counselling - Obesity referral, monitoring, assessment and treatment, seen dietician. Y
Primary Care Weight management programmes including National Obesity Observatory Standard Evaluation Framework for weight management interventions - participant satisfaction with intervention Y
Primary Care Reason for obesity therapy - occupational Y
Primary Care Dementia care plan/review/monitoring Y
Primary Care Misuse various substances Y
Psychotherapy Substance/Drug misuse assessment/clinical management plan Y
Psychotherapy Substance misuse detoxification /maintenance therapy Y
Medications Dementia medication review Y
Medications Anti-obesity drug therapy Y
Medications Asthma medication review Y
Medications Long Term Depression Medications Y
Medications Nicotine replacement therapy Y
Medications Riluzole 50mg Y
Medications Rilutex 50mg Y
Medications Amyotrophic lateral sclerosis drugs Band 1 Y
Medications Anti-obesity drug therapy Y

Mental Health Status

Sub-category Variable type Baseline
Addictions Alcohol dependent events Y
Addictions Chronic alcoholism Y
Addictions Mental and behavioural disorders due to use of alcohol Y
Addictions Aversion therapy - alcoholism Y
Addictions Alcoholic rehabilitation program Y
Addictions Nondependent alcohol abuse in remission Y
Addictions Drug addict/user/drug misuse Y
Addictions Dependence on illicit or recreational drugs Y
Addictions Misuse of illicit or recreational drugs, solvents, anti-depressants, other substances/misuse frquency Y
Addictions Age at starting and history of drug or various substances misuse Y
Addictions Mental and behavioural disorders due to use of various drugs use and use of other psychoactive substances Y
Addictions Accidental or Intentional poisoning by and exposure to narcotics and psychodysleptics drugs Y
Addictions Buying drugs/amount spent per day Y
Addictions Dealing with/selling drugs Y
Addictions Drug paraphernalia Y
Addictions Non-dependence various substances abuse Y
Addictions Behavioural tolerance to drug Y
Addictions Time devoted to drug related activity Y
Addictions Mental and behavioural disorder due to use of tobacco Y
Addictions History of tobacco abuse Y
Addictions Tobacco Abuse Counselling Y
Mood Depression Y
Mood Depression/depressive episode - mild, moderate or severe Y
Mood Chronic depression Y
Mood Reactive Depressive psychoses Y
Mood Single depressive disorder episode Y
Mood Recurrent depressive disorders Y
Mood Seasonal affective disorder (SAD) Y
Mood Ante-natal or puerperal depression Y
Mood Mixed anxiety and depressive disorder Y
Mood Depressive conduct disorder Y
Mood Other mood disorders Y
Mood Alcoholic jealousy Y


Sub-category Variable type Baseline
Cognitive Status Parkinson's disease Y
Cognitive Status Alzheimer's disease -all cause Y
Cognitive Status Dementia Y
Cognitive Status Alcoholic dementia Y
Cognitive Status Senile dementia with depression Y
Cognitive Status Presenile dementia with depression Y
Cognitive Status Arteriosclerotic dementia with depression Y
Cognitive Status Dementia diagnosis date Y
Cognitive Status Dementia diagnosis flag Y
Cognitive Status Dementia with Lewy bodies diagnosis flag Y
Cognitive Status Frontotemporal dementia diagnosis flag Y
Cognitive Status Alzheimer's disease diagnosis flag Y
Cognitive Status Vascular dementia diagnosis flag Y


Sub-category Variable type Baseline
Alcohol Very heavy drinker/alcoholism Y
Smoking Smoker/Tobacco user Y
Smoking Type cigarette/cigar/pipe Y
Smoking Amount Y
Smoking Cigarette pack-years Y
Smoking Former smoker -Type cigarette/cigar/pipe Y
Smoking Former smoker -Amount Y
Smoking Thinking about/Trying to give up smoking Y
Smoking Failed attempt to stop/restarted smoking Y
Smoking Total time smoked Y
Substance Misuse Various substances Y
Substance Misuse Has never misused drugs Y

Physical Examination

Sub-category Variable type Baseline
Anthropometry BMI Y
Anthropometry Weight (gain due to drugs) Y

Linkage Data

Sub-category Variable type Baseline
Death register Mortality (Status from Annual District Death Extract (ADDE)) Y
HES Hospital Admissions (Patient Episode Database for Wales (PEDW)) Y
Primary Care Welsh Longitudinal General Practice Dataset(WLGP) Y


Sub-category Variable type Baseline
BMD DXA scan result osteoporotic - Heel Y
BMD DXA scan result osteoporotic - Forearm Y
BMD DXA scan result osteoporotic - Hip Y
BMD DXA scan result osteoporotic - Lumbar Y
BMD DEXA scan result osteoporotic - Femoral neck Y
BMD DXA scan T score -Heel Y
BMD DXA scan T score -Hip Y
BMD DXA scan T score - Lumbar Spine Y
BMD DEXA scan T score - Femoral neck Y
BMD QUI (Quantitative ultrasound) scan result osteoporotic - heel Y