Table 1.
Patient related variables to be included in the planned study
| Variable | Dataset | How will data be presented | Method of measurement |
|---|---|---|---|
| Age | NJR | Continuous and age categories | Derived from the date of birth and date of surgery |
| Sex | NJR | Categorical: Male/Female/Indeterminate | Documented directly using a specified list on MDS collection form |
| BMI | NJR | Continuous and categorical: Underweight/Normal/Overweight/Obese/Morbidly obese | Documented directly or derived from the weight and height of the patient |
| Dominant hand | NJR | Categorical: Yes/No/Unknown | Documented directly using a specified list on MDS collection form |
| ASA | NJR | Categorical: ASA1-ASA5 | Documented directly using a specified list on MDS collection form |
| Indication for surgery | NJR |
Categorical: (1) Trauma/Elective (2) Acute trauma/inflammatory/Trauma Sequalae/Osteoarthritis/Other |
Documented directly using a specified list on MDS collection form |
| Socioeconomic status | NJR | Categorical: Indices of multiple deprivation quintiles (2015 version) | Derived from the postcodes and reported as index of deprivation quintiles |
| Ethnicity | HES | Categorical: Asian, Asian British, or Asian Welsh/Black, Black British, Black Welsh, Caribbean or African/White/Mixed or Multiple ethnic groups/Other ethnic group/Does not apply (students and schoolchildren living away during term-time) | Documented in patient medical records. Classification is based on the ONS group classification 6a [26] |
| Co-morbidities | HES |
(1) Categorical: Acute MI/CHF/PVD/Cerebrovascular Disease/Dementia/COPD/Rheumatoid Disease/Peptic Ulcer/Mild liver disease/Diabetes/Diabetes + Complications/Hemiplegia or Paraplegia/Renal disease/Cancer/Moderate/Severe liver disease/Metastatic Cancer/AIDS/Depression/Anxiety/Osteoporosis (2) Original Charlson Comorbidity Index Hospital (3) Charlson Comorbidity Index Hospital with revised weights |
Documented in patient medical records and extracted by admin team at the time of discharge and reported using ICD-10 codes The Charlson Comorbidity Index will be derived from pre-existing condition recorded on HES-APC data using ICD-10 codes |
ASA American Society of Anaesthesiologists, BMI: Body Mass Index, MI myocardial infarction, CHF congestive heart failure, PVD peripheral vascular disease, COPD chronic obstructive pulmonary disease