Variable | Details/categories | Type of measurement | Number of variables* |
Demographic | |||
Age | Age at admission to hospital (in years) | Continuous numeric | 1 |
Socioeconomic status | Based on the English indices of deprivation 2015 (Index of Multiple Deprivation Rank) | Continuous numeric | 1 |
Patient-related | |||
Previous allergy/adverse drug reaction | Yes/No | Binary | 1 |
Body mass index | First documented result following admission | Continuous numeric | 1 |
Number of hospital admissions | Number of admissions to the study hospital in the previous 6 months | Continuous numeric | 1 |
Primary diagnosis | Categorised by ICD-10 coding:
| Nominal categorical | 6 |
Number of comorbidities | From hospital clinical coding data (ICD-10 codes) | Continuous numeric | 1 |
History of dementia | From hospital clinical coding data (ICD-10 codes) | Binary | 1 |
Medicines-related | |||
Number of medicines prescribed | Number of ‘regular’ medicines prescribed on the first full day of admission to hospital (ie, excluding ‘when required’ and ‘once only’ medicines, dietary products, non-medicated topical products (eg, emollients), wound dressings) | Continuous numeric | 1 |
Use of ‘high risk medicines’ | Prescribed as a ‘regular’ medicine during the hospital admission:
| Binary (for each group) | 15 |
Parenteral administration route | Administration of one or more regular medicines via the parenteral route (intravenous, intramuscular, subcutaneous) during the hospital admission (excluding prophylactic low molecular weight heparins, fluid replacement therapy) | Binary | 1 |
Laboratory results | |||
Renal function | Creatinine clearance calculated using the Cockcroft-Gault equation (using first documented results following admission) | Continuous numeric | 1 |
Liver disease | Liver disease defined as ALT/ALP and/or bilirubin ≥3 times normal range and/or documented liver disease Laboratory results will be the first documented results following admission Documented liver disease will be established from hospital clinical coding data (ICD-10 codes) | Binary | 1 |
Serum albumin | First documented result following admission | Continuous numeric | 1 |
Serum potassium | First documented result following admission | Continuous numeric | 1 |
Serum sodium | First documented result following admission | Continuous numeric | 1 |
White cell count | First documented result following admission | Continuous numeric | 1 |
Platelet count | First documented result following admission | Continuous numeric | 1 |
Total number of variables* | 37 |
*Number of variables in relation to calculating the ‘events per variable’.
ALP, alkaline phosphatase; ALT, alanine aminotransferase; ICD, International Statistical Classification of Disease and Related Problems.