Analysis rules and coding structure
INDEX
1. Analysis Rules…………………………………………………………..………………………….2
2. Data Dictionary for final Patient Dataset……………………….…………………….4
3 Socio-economic calculation…………...... …………………… 9
4 Code lists………………………………………...... …………………...... 11
1. Analysis Rules
All patients diagnosed with Asthma but no COPD at any time from the GPRD database of 474,242 patients.
1.1 IPDI Cohorts with defined categories of:
ICS - patients who initiate their anti-asthma treatment with ICS of any dose.
COMBO – patients who initiate their anti-asthma treatment with combined ICS and a long-acting antagonisit of any dose. (Note: if they receive single ICS on same day, patient is defined as a combo initiated.)
LABA - patients who initiate their anti_asthma treatment with a long acting antagnonist.
LTRA - patient who initiate their anti-asthma treatment with a leukatriene antagonist.
1.2 IPDC cohort with defined categories as:
ICS - patients from the IPDI ICS cohort who then experience their FIRST CHANGE as an INCREASE in their ICS therapy in either dose or formulation
COMBO - patients from the IPDI ICS cohort who then experience their FIRST CHANGE as a switch to a combined inhaled steroid and long-acting antagonist
LABA - patients from the IPDI ICS cohort who then experience their FIRST CHANGE as the addition of a long-acting antagonist to their ICS therapy.
LTRA - patients from the IPDI ICS cohort who then experience their FIRST CHANGE as the addition of a leukatriene antagonist.
1.3 IPDA cohort with defined categories as:
COMBO - patients from the IPDI LABA cohort who then experience their FIRST change as a switch from a fixed combination to separate inhalers.
LABA - patients from the IPDI COMBO cohort who experience their FIRST CHANGE as a switch from separate inhalers to fixed combination.
LTRA - patients from the IPDI LABA/COMBO cohorts who experience their FIRST CHANGE as the addition of a leukatriene antagonist to their initiating therapy.
1.4 Time Period
Ensure that for each patient identified in each cohort, there is 1 year’s worth of baseline data prior to index prescription date and 1 years worth of outcome data after index prescription date.
1.5 Determining outcomes:
1.5.1 Success Outcomes:
a) No recorded hospital attendances for asthma including admission, A&E or OPD attendance,
b) no prescriptions for oral steroids,
c) and an average daily dosage of salbutamol of no more than 100mcg or terbutaline 250mcg.
1.5.2 Partial Outcomes:
a) No recorded hospital attendances for asthma including admission, A&E or OPD attendance,
b) maximum of 2 oral steroids
c) and an average daily dosage of salbutamol of between 101mcg and 400mcg or terbutaline 251mcg to 1000mcg.
1.5.3 Unsuccessful Outcomes:
a) 1 or more hospital attendances for asthma, or
b) more than 2 oral steroids
d) or an average daily dose of salbutamol of more than 400mcg or terbutaline 1000mcg
1.6 Heights and Weights *
Last recorded measurements prior to IPDI.
Adults – Height > 1.5 metres and < 2.2
- Weight > 40kg and < 200kg
Children over 5 – Height: > 0.5 metres and < 2.2
- Weight: > 10kg and < 200kg
Children under 5 – Accept current values
1.7 SABA Daily Dose salbutamol equivalent**
SALBUTAMOL – SABA daily dosage / 200
TERBUTALINE – SABA daily dosage / 500
2. Data Dictionary of Final Patient Dataset
IPD / IPDI,IPDC or IPDA patient
PatEID / Unique Patient ID / GPRD
EventDate / Date at IPD / Either the date of ICS initiation or the date of change of treatment
Category / Stage of asthma treatment
Continuous_Therapy / Indication that 2nd treatment occurred within 3 month window after IPDI
Age / Age – derived field calculated using birthyear and IPD date / Age at IPD date. Calculated as from 1 Jan
Birthyear / Patients year of birth / GPRD
Gender / Derived from title of patient
Height / * Height of patient prior to IPD – measured in metres / Recorded closest to date of IPD
Weight / * Weight of patient prior to IPD – measured in kilogrammes / Recorded closest to date of IPD
Socio-Economic_Status / +Practice postcode linked IMD score (see notes) / GPRD
Rank / Country specific SES quintile - 0 is best, 4 worst / GPRD
Practice_Name / NHS region in which the practice is based / GPRD
Practice_Region / The name of the SHA / GPRD
Practice_Name / Codes for England, Scotland, Northern Ireland and Wales / GPRD
PF_best_ever / Typecode – 007R / Last recorded best ever reading prior to IPD
Date_PF_best_ever / Date of best ever reading
Height_PF_best_ever / Last Height recorded prior to date of best ever
Date_Height_PF_best_ever / Date of best ever height recorded
PF_current / Typecode – 007T / Last recorded current reading prior to IPD
Date_PF_current / Date of current result
Height_PF_current / Last Height recorded prior to date of current reading
Date_ Height_PF_current / Date of current height recorded
PF_last_attack_after_nebuliser / Typecode – 007Q / Last recorded after nebuliser reading prior to IPD
Date_ PF_last_attack_after_nebuliser / Date of pf reading for last attack after nebuliser
Height_ PF_last_attack_after_nebuliser / Last height recorded prior to last attack after nebuliser
Date_Height_ PF_last_attack_after_nebuliser / Date of height recording
PF_last_attack_before_nebuliser / Typecode – 007P / Last recorded before nebuliser reading prior to IPD
Date_
PF_last_attack_before_nebuliser / Date of pf reading for last attack before nebuliser
Height_PF_last_attack_before_nebuliser / Last height recorded prior to pf reading of last attack before nebuliser
Date_Height_ PF_last_attack_before_nebuliser / Date of height recording
PF_predicted / Typecode – 007S / Last recorded predicted reading prior to IPD
Date_PF_predicted / Date of predicted result
Height_PF_predicted / Last height taken prior to pf predicted recording
Date_Height_PF_predicted / Date of height
Date Asthma Diagnosis / First date asthma diagnosed / 1 Year prior to IPD
SABA Scripts / Count of SABA scripts / 1 Year prior to IPD
SABA Inhalers / No of actual inhalers prescribed / 1 Year prior to IPD
SABA daily dose / **SABA daily doses (see note) / 1 Year prior to IPD
Oral steroids / Count of oral steroids prescribed / 1 Year prior to IPD
Candidiasis definite / Count of definite oral candidiasis diagnosed / 1 Year prior to IPD
Candidiasis definite antifungal possible / Count of definite oral candidiasis with a possible antifungal prescription / 1 Year prior to IPD
Candidiasis possible antifungal possible / Count of possible oral candidiasis diagnosis with a possible antifungal prescription / 1 Year prior to IPD
Candidiasis possible antifungal probable / Count of possible oral candidiasis diagnosis with a probable antifungal prescription / 1 Year prior to IPD
Asthma scripts / Count of scripts for asthma or allergy drugs – grouped by patient and date / 1 Year prior to IPD
Asthma consultations / Count of consultations where asthma was recorded / 1 Year prior to IPD
Accident and Emergency / Count of accident and emergency admissions for asthma / 1 Year prior to IPD
Accident and Emergency Resp / Count of accident and emergency admissions for respiratory reasons / 1 Year prior to IPD
Hospital Asthma definite / Count of hospital admissions for definite asthma / 1 Year prior to IPD
Hospital asthma definite plus vague / Count of hospital admissions for definite asthma as well any vague admissions / 1 Year prior to IPD
Hospital Asthma & Resp / Count of hospital admissions for definite asthma as well any vague admissions plus any definite respiratory admissions / 1 Year prior to IPD
Hospital Asthma & Resp plus vague / Count of hospital admissions for definite asthma as well any vague admissions plus any definite respiratory admissions plus vague respiratory admissions / 1 Year prior to IPD
OPD Hospital attendances / Planned hospital referral for asthma / 1 Year prior to IPD
Antibiotics / Count of antibiotics prescribed for any LRTI or URTI diagnosis / 1 Year prior to IPD
Rhinitis_clinical / Y/N - Indicates diagnosis of Rhinitis – Read Codes Only / At any time
Rhinitis_therapy / Prescribed Antihistamines or Nasal Steroids / At any time
Rhinitis_all / Set to ‘Y’ if either Rhinitis_clinical or Rhinitis_therapy = ‘Y’ / At any time
COPD / Y/N - Indicates diagnosis of COPD / At any time
GERD / Y/N - Indicates diagnosis of GERD / At any time
Cardiac Disease / Y/N - Indicates diagnosis of Cardiac Disease / At any time
Other Respiratory / Y/N - Indicates diagnosis of any other respiratory code not already catered for / At any time
Smoking / 1 indicates ‘Non-Smoker’
2 indicates ‘Current Smoker’
3 indicates ‘Ex-Smoker’
4 indicates ‘Passive Smoker’
-1 indicates ‘Unknown’ / Closest to IPD prior to IPD. Extracted at any time.
Smoking_All / As above – data taken from smoking table, clinical table and status table. / As Above PLUS closest to IPD but also checked first diagnosis after IPD
NSAIDS / Y/N indicator – received during period / 1 Year prior to IPD
Paracetamol / Y/N indicator – received during period / 1 Year prior to IPD
Beta_blockers / Y/N indicator – received during period / 1 Year prior to IPD
Asthma control group / Outcome of treatment since IPDI (see appendix b) / Based on 1 Year after IPD
Asthma_group_code / Success = 1, Partial = 2, Failure=3
Asthma_Success_Group / Success or Partial = 1,Failure = 2
Asthma_Failure_Group / Success = 1, Partial or Failure = 2
PF_best_ever_outcome / Typecode – 007R / Last recorded best ever reading after IPD
Date_PF_best_ever_outcome / Date of best ever reading / Date
Height_PF_best_ever_outcome / First Height recorded after date of best ever
Date_Height_PF_best_ever_outcome / Date of best ever height recorded
PF_current_outcome / Typecode – 007T / Last recorded current reading after IPD
Date_PF_current_outcome / Date of current result
Height_PF_current_outcome / First Height recorded after date of current reading
Date_ Height_PF_current_outcome / Date of current height recorded
PF_last_attack_after_nebuliser_outcome / Typecode – 007Q / Last recorded after nebuliser reading after IPD
Date_ PF_last_attack_after_nebuliser_outcome / Date of pf reading for last attack after nebuliser
Height_ PF_last_attack_after_nebuliser_outcome / First height recorded after last attack after nebuliser
Date_Height_ PF_last_attack_after_nebuliser_outcome / Date of height recording
PF_last_attack_before_nebuliser_outcome / Typecode – 007P / Last recorded before nebuliser reading after IPD
Date_
PF_last_attack_before_nebuliser_outcome / Date of pf reading for last attack before nebuliser
Height_ PF_last_attack_before_nebuliser_outcome / First height recorded after pf reading of last attack before nebuliser
Date_Height_ PF_last_attack_before_nebuliser_outcome / Date of height recording
PF_predicted_outcome / Typecode – 007S / Last recorded predicted reading after IPD
Date_PF_predicted_outcome / Date of predicted result
Height_PF_predicted_outcome / First height after pf predicted recording
Date_Height_PF_predicted_outcome / Date of height
Oral steroids outcome / Count of oral steroids / Based on 1 Year after IPD
Candidiasis definite outcome / Count of definite oral candidiasis diagnosed / Based on 1 Year after IPD
Candidiasis definite antifungal possible outcome / Count of definite oral candidiasis with a possible antifungal prescription / Based on 1 Year after IPD
Candidiasis possible antifungal possible outcome / Count of possible oral candidiasis diagnosis with a possible antifungal prescription / Based on 1 Year after IPD
Candidiasis possible antifungal probable outcome / Count of possible oral candidiasis diagnosis with a probable antifungal prescription / Based on 1 Year after IPD
Asthma scripts outcome / Count of scripts for asthma or allergy drugs – grouped by patient and date / Based on 1 Year after IPD
Asthma consultation outcome / Count of consultations where asthma was recorded / Based on 1 Year after IPD
Accident and Emergency outcome / Count of accident and emergency admissions for asthma reasons / Based on 1 Year after IPD
Accident and Emergency Resp outcome / Count of accident and emergency admissions for respiratory reasons / Based on 1 Year after IPD
Hospital Asthma definite outcome / Count of hospital admissions for definite asthma / Based on 1 Year after IPD
Hospital asthma definite plus vague outcome / Count of hospital admissions for definite asthma as well any vague admissions / Based on 1 Year after IPD
Hospital Asthma & Resp outcome / Count of hospital admissions for definite asthma as well any vague admissions plus any definite respiratory admissions / Based on 1 Year after IPD
Hospital Asthma & Resp plus vague outcome / Count of hospital admissions for definite asthma as well any vague admissions plus any definite respiratory admissions plus vague respiratory admissions / Based on 1 Year after IPD
OPD Hospital attendances outcome / Planned hospital referral for asthma / Based on 1 Year after IPD
Antibiotic outcome / Count of antibiotics prescribed for any LRTI or URTI diagnosis / Based on 1 year after IPD
SABA scripts outcome / Count of SABA scripts / Based on 1 Year after IPD
SABA inhalers outcome / No of actual inhalers prescribed / Based on 1 year after IPD
SABA daily dose outcome / ** SABA daily doses (see note) / Based on 1 Year after IPD
ICS_Dosage_before_IPD / Actual bdp dosage from last ICS before IPD / Before IPD
ICS_Dosage_at_IPD / Actual bdp dosage from first ICS at /after IPD / On or After IPD
ICS_1 / 1st ICS drug prescribed at IPD
ICS_2 / 2nd ICS drug prescribed on IPD
Combo_1 / 1st Combo drug prescribed at IPD
Combo_2 / 2nd Combo drug prescribed at IPD
LABA / Laba drug prescribed at IPD
LTRA / Ltra drug prescribed at IPD
Prior_ICS_1 / 1st ICS drug prescriped prior to IPDC/IPDA
Prior_ICS_2 / 2nd ICS drug prescribed prior to IPDC/IPDA
SABA_daily_dosage_outcome / SABA daily dose outcome * MCG – SALBUTAMOL equivalent / Based on 1 Year after IPD
2 Socio-Economic calculation
SES has been assigned to practices using the Index of Multiple Deprivation (IMD) as a proxy measure. IMD was captured for the whole of the UK in 2000, divided into England, Wales, Scotland and Northern Ireland. The IMD for Scotland and England were updated in 2004. An update for Wales is expected in summer 2005.
The IMD is derived by weighted contributions for a number of different categories. These categories are weighted differently for England, Scotland, Wales and Northern Ireland. They involve a selection of the following for each nation
Income
Employment
Health Deprivation & Disability
Education Skills & Training