Print

Smoking Status

David Reeves, David A Springate, Darren M Ashcroft, Ronan Ryan, Tim Doran, Richard Morris, Ivan Olier, Evangelos Kontopantelis

Type
Lifestyle Risk Factor
ID
PH621
Version ID
1242
Data Sources
Valid event data range
01/01/1996 - 17/12/20003
Sex
Female, Male
Agreement Date
2014-04-23
Coding system
Read codes v2 OXMIS codes
Tags /Collections
ClinicalCodes Repository Phenotype Library

Definition

Data:

CPRD and THIN obtain their data from practices using the Vision electronic record system, while QResearch obtains data from practices using EMIS software. We felt that comparisons would be most informative between databases drawing data from different capture systems. Across the time-period studied, two versions of EMIS were in use, the more common being the text-based EMIS LV system with navigation and data entry mainly via the keyboard; EMIS PCS, which is Windows-based with mouse control and drop-down menus, was introduced from 1999. Vision was Windows-based throughout the study period. A small-scale direct comparison of EMIS LV and Vision indicated that coded data entry, excepting prescribing information, was faster with Vision and that more items were likely to be coded. Practices running Vision have slightly higher achievement rates for most Quality and Outcomes Framework (QOF) indicators than practices running either version of EMIS, even after controlling for differences in practice and area characteristics. We had access to CPRD, and therefore chose to replicate a study previously conducted using QResearch. CPRD and QResearch both draw data from general practices spread throughout the UK—currently more than 600 practices each—and comparisons to the national age-gender structure and prevalence rates for common conditions mostly show good correspondence for both datasets. For practical reasons, we focused on studies of the effectiveness of medicinal interventions and, after assessing the available studies, chose to replicate an investigation into the effects of statins on the mortality of patients with ischaemic heart disease (IHD) by Hippisley-Cox and Coupland (H-C&C). The methodological details provided in the published paper were insufficient on their own to allow a close replication to be conducted, and we therefore obtained additional details from the authors. We requested purely factual information about the methods used and did not share any of our analyses or results. We replicated the methods of H-C&C as closely as possible, given the differences between the two databases. All of the methods described below, including the study period, variable specifications and analytical procedures, are exact replications of those used in the original study, unless indicated otherwise. We selected all practices in CPRD that provided up to standard (UTS) data (UTS is CPRD’s designation for data meeting their internal quality standards) for the whole of the period from 1 January 1996 to 17 December 2003. We next identified all patients with a first diagnosis of IHD within this period, based on the QOF business rules for 2004. We excluded patients whose IHD diagnosis fell within the first 3 months of registration with their general practice or was on or subsequent to their recorded date of death, or who were prescribed statins prior to first diagnosis. We extracted data for these patients from the date of IHD diagnosis up until 17 December 2003, or until the date of death or exit from the practice, or the last recorded date for practices that stopped providing data before 17 December 2003, giving a maximum possible length of follow-up postdiagnosis of just under 8 years.

Analysis:

The main outcome was all-cause mortality, identified through a record of death in the CPRD. Following H-C&C, we conducted two main analyses: (1) a cohort analysis and (2) a case-control analysis nested within the full cohort. All analyses were conducted using R. Following H-C&C, statistical significance was assessed using p<0.01 (two tailed), but 95% CIs are reported in tables and figures. We made an a priori decision not to attempt to ‘improve’ on the analysis conducted by H-C&C, as our specific aim was to determine whether the same results and conclusions would emerge from using identical methods on a different underlying dataset targeting the same population.

Cohort analysis:

The cohort analysis used a Cox proportional hazards model to examine the effect of statin use on patient survival, with survival time determined by the time (in days) between the date of first diagnosis and date of death. Patients who transferred out of their practice before death or who were still alive at the end of the study period were treated as censored observations. Statin exposure was used as a time-varying covariate, with the period of exposure from the date of first prescription to when the statin was stopped (estimated as the date of last prescription plus 90 days; intervening breaks in the use of statins were ignored), or if not stopped until the end of the study period, date of death or date of transfer out of practice. Covariates adjusted for in the analysis were year of diagnosis, gender, comorbidities (diabetes, hypertension, myocardial infarction, congestive cardiac failure and cancer), and age (coded as 0–44, 45–54, 55–64, 65–74, 75–84, 85–94 or ≥95), smoking (ever smoked, never smoked, not recorded) and body mass index (BMI; coded as <25, 25–30, >30 kg/m2) all at the date of diagnosis. The presence of each comorbidity was indicated by a diagnosis in the patient record (using the 2004 QOF business rules) and coded as present/not present at the date of IHD diagnosis. If smoking status or BMI was not recorded within 4 years prior to diagnosis of IHD, we coded it as missing. The analysis was undertaken using the R survival analysis package accounting for the clustering of patients by practice and using the Huber-White robust estimate of SE. The proportional hazards assumption was checked graphically and with a test for proportional hazards.

Nested case-control study:

The nested case-control analysis compared all patients from the cohort who died during the follow-up period (the cases) with a group of matched control patients (also with IHD) who did not die. For each case, we defined an ‘index date’ as the date of death. We then used an incidence density sampling procedure (as per the original study; personal correspondence) to randomly select four control patients for each case matched on gender, year of IHD diagnosis and age (coded in 5-year age-bands). General practice was not used as a matching variable. Controls were patients with IHD alive at the time their matched case died (including patients who themselves became cases at a later time-point). The incidence sampling procedure allowed the same patient to be selected as a control for more than one case, thus providing a full set of four controls for each case, while still producing unbiased estimates of risk. Statin exposure was based on the first and last prescription dates prior to the index date and coded into: (1) currently taking statins (last prescription was within 90 days of the index date); (2) previously took statins (last prescription more than 90 days prior to the index date) and (3) has never taken statins. We did this for all statins as a group and also separately for five different types of statin (atorvastatin, cerivastatin, fluvastatin, pravastatin and simvastatin). For ‘all statins’, the last prescription could be for a different statin type than the first; for individual statins, it had to be the same type. One further formulation, rosuvastatin, was in use that did not appear in the QResearch study. We included this in the ‘all statins’ group but did not analyse it individually as only 22 patients had received the statin. Analysis of the case-control study used conditional logistic regression accounting for the matching of cases with controls, to obtain ORs for the risk of death in relation to use of statins. We allowed for clustering by general practice and used a robust estimate of SE, in line with the cohort analysis. Covariates in the analysis were smoking status, BMI and comorbidities, specified as in the Cohort analysis but based on the index date rather than the date of diagnosis. Additional covariates in this analysis were the Townsend deprivation score for the practice postcode (in national quintiles; H-C&C used quintiles of patient-level Townsend scores) and use of β-blockers, aspirin, ACE inhibitors and calcium channel blockers, identified through the British National Formulary chapter codes in the patient record. Each medication was coded as either used or not used prior to the index date but after the date of IHD diagnosis. Interactions between use of statins and each of gender, age (less than 75 vs 75 and over) and diabetes were tested by adding interaction terms into the model.

Publications

  • David Reeves, David A Springate, Darren M Ashcroft, Ronan Ryan, Tim Doran, Richard Morris, Ivan Olier, Evangelos Kontopantelis, Can analyses of electronic patient records be independently and externally validated? The effect of statins on the mortality of patients with ischaemic heart disease: a cohort study with nested case–control analysis. BMJ Open, 4:e004952 2014.

Clinical Code List

Rows: 111
Code Description Entity type Coding System (OXMIS Read) Category
137..00 Tobacco consumption smoking_status Read observation
137..11 Smoker - amount smoked smoking_status Read observation
1371.00 Never smoked tobacco smoking_status Read observation
1371.11 Non-smoker smoking_status Read observation
1372.00 Trivial smoker - < 1 cig/day smoking_status Read observation
1372.11 Occasional smoker smoking_status Read observation
1373.00 Light smoker - 1-9 cigs/day smoking_status Read observation
1374.00 Moderate smoker - 10-19 cigs/d smoking_status Read observation
1375.00 Heavy smoker - 20-39 cigs/day smoking_status Read observation
1376.00 Very heavy smoker - 40+cigs/d smoking_status Read observation
1377.00 Ex-trivial smoker (<1/day) smoking_status Read observation
1378.00 Ex-light smoker (1-9/day) smoking_status Read observation
1379.00 Ex-moderate smoker (10-19/day) smoking_status Read observation
137A.00 Ex-heavy smoker (20-39/day) smoking_status Read observation
137B.00 Ex-very heavy smoker (40+/day) smoking_status Read observation
137C.00 Keeps trying to stop smoking smoking_status Read observation
137D.00 Admitted tobacco cons untrue ? smoking_status Read observation
137E.00 Tobacco consumption unknown smoking_status Read observation
137F.00 Ex-smoker - amount unknown smoking_status Read observation
137G.00 Trying to give up smoking smoking_status Read observation
137H.00 Pipe smoker smoking_status Read observation
137I.00 Passive smoker smoking_status Read observation
137J.00 Cigar smoker smoking_status Read observation
137K.00 Stopped smoking smoking_status Read observation
137L.00 Current non-smoker smoking_status Read observation
137M.00 Rolls own cigarettes smoking_status Read observation
137N.00 Ex pipe smoker smoking_status Read observation
137O.00 Ex cigar smoker smoking_status Read observation
137P.00 Cigarette smoker smoking_status Read observation
137P.11 Smoker smoking_status Read observation
137Q.00 Smoking started smoking_status Read observation
137Q.11 Smoking restarted smoking_status Read observation
137R.00 Current smoker smoking_status Read observation
137S.00 Ex smoker smoking_status Read observation
137T.00 Date ceased smoking smoking_status Read observation
137U.00 Not a passive smoker smoking_status Read observation
137V.00 Smoking reduced smoking_status Read observation
137W.00 Chews tobacco smoking_status Read observation
137X.00 Cigarette consumption smoking_status Read observation
137Y.00 Cigar consumption smoking_status Read observation
137Z.00 Tobacco consumption NOS smoking_status Read observation
137a.00 Pipe tobacco consumption smoking_status Read observation
137b.00 Ready to stop smoking smoking_status Read observation
137c.00 Thinking about stopping smoking smoking_status Read observation
137d.00 Not interested in stopping smoking smoking_status Read observation
137e.00 Smoking restarted smoking_status Read observation
137f.00 Reason for restarting smoking smoking_status Read observation
137g.00 Cigarette pack-years smoking_status Read observation
137h.00 Minutes from waking to first tobacco consumption smoking_status Read observation
13WF.00 Family smoking history smoking_status Read observation
13WF.11 Smoker in the family smoking_status Read observation
13WF100 Father smokes smoking_status Read observation
13WF200 Mother smokes smoking_status Read observation
13WF300 Both parents smoke smoking_status Read observation
13WF400 Passive smoking risk smoking_status Read observation
13WI.00 Parents do not smoke smoking_status Read observation
13WK.00 No smokers in the household smoking_status Read observation
13cA.00 Smokes drugs smoking_status Read observation
13p..00 Smoking cessation milestones smoking_status Read observation
13p0.00 Negotiated date for cessation of smoking smoking_status Read observation
13p1.00 Smoking status at 4 weeks smoking_status Read observation
13p2.00 Smoking status between 4 and 52 weeks smoking_status Read observation
13p3.00 Smoking status at 52 weeks smoking_status Read observation
13p4.00 Smoking free weeks smoking_status Read observation
13p5.00 Smoking cessation programme start date smoking_status Read observation
177..00 Smoke inhalation smoking_status Read observation
6791.00 Health ed. - smoking smoking_status Read observation
67A3.00 Pregnancy smoking advice smoking_status Read observation
67H1.00 Lifestyle advice regarding smoking smoking_status Read observation
745H.00 Smoking cessation therapy smoking_status Read observation
745H000 Nicotine replacement therapy using nicotine patches smoking_status Read observation
745H100 Nicotine replacement therapy using nicotine gum smoking_status Read observation
745H200 Nicotine replacement therapy using nicotine inhalator smoking_status Read observation
745H300 Nicotine replacement therapy using nicotine lozenges smoking_status Read observation
8B2B.00 Nicotine replacement therapy smoking_status Read observation
8B3Y.00 Over the counter nicotine replacement therapy smoking_status Read observation
8B3f.00 Nicotine replacement therapy provided free smoking_status Read observation
8BP3.00 Nicotine replacement therapy provided by community pharmacis smoking_status Read observation
8CAL.00 Smoking cessation advice smoking_status Read observation
8CAg.00 Smoking cessation advice provided by community pharmacist smoking_status Read observation
8H7i.00 Referral to smoking cessation advisor smoking_status Read observation
8HTK.00 Referral to stop-smoking clinic smoking_status Read observation
8I2I.00 Nicotine replacement therapy contraindicated smoking_status Read observation
8I39.00 Nicotine replacement therapy refused smoking_status Read observation
8I6H.00 Smoking review not indicated smoking_status Read observation
9N2k.00 Seen by smoking cessation advisor smoking_status Read observation
9N4M.00 DNA - Did not attend smoking cessation clinic smoking_status Read observation
9OO..00 Anti-smoking monitoring admin. smoking_status Read observation
9OO..11 Stop smoking clinic admin. smoking_status Read observation
9OO..12 Stop smoking monitoring admin. smoking_status Read observation
9OO1.00 Attends stop smoking monitor. smoking_status Read observation
9OO2.00 Refuses stop smoking monitor smoking_status Read observation
9OO3.00 Stop smoking monitor default smoking_status Read observation
9OO4.00 Stop smoking monitor 1st lettr smoking_status Read observation
9OO5.00 Stop smoking monitor 2nd lettr smoking_status Read observation
9OO6.00 Stop smoking monitor 3rd lettr smoking_status Read observation
9OO7.00 Stop smoking monitor verb.inv. smoking_status Read observation
9OO8.00 Stop smoking monitor phone inv smoking_status Read observation
9OO9.00 Stop smoking monitoring delete smoking_status Read observation
9OOA.00 Stop smoking monitor.chck done smoking_status Read observation
9OOZ.00 Stop smoking monitor admin.NOS smoking_status Read observation
9hG..00 Exception reporting: smoking quality indicators smoking_status Read observation
9hG0.00 Excepted from smoking quality indicators: Patient unsuitable smoking_status Read observation
9hG1.00 Excepted from smoking quality indicators: Informed dissent smoking_status Read observation
H310100 Smokers' cough smoking_status Read observation
SM7y200 Smoke inhalation smoking_status Read observation
SM7z.11 Smoke inhalation smoking_status Read observation
ZG23300 Advice on smoking smoking_status Read observation
ZRaM.00 Motives for smoking scale smoking_status Read observation
ZRh4.00 Reasons for smoking scale smoking_status Read observation
ZRh4.11 RFS - Reasons for smoking scale smoking_status Read observation
Rows: 40
Code Description Entity type Coding System (OXMIS Read) Category
5020M SMOKERS' THROAT smoking_status OXMIS observation
5287MK SMOKERS' MOUTH PATCHES smoking_status OXMIS observation
9879MK SMOKE INHALATION smoking_status OXMIS observation
L5090B PARENTS BOTH SMOKE smoking_status OXMIS observation
L5091S SMOKING STARTED smoking_status OXMIS observation
T509 SMOKER smoking_status OXMIS observation
T509 SR SMOKING RESTARTED smoking_status OXMIS observation
T5090OR SMOKER OWN ROLLED smoking_status OXMIS observation
T5090XC SMOKER CIGARETTES smoking_status OXMIS observation
T5091 STOPPED SMOKING smoking_status OXMIS observation
T5091ES FORMER SMOKER smoking_status OXMIS observation
T5091HS EX HEAVY SMOKER smoking_status OXMIS observation
T5092 SMOKING ADVISED TO STOP smoking_status OXMIS observation
T5092S SMOKING WISHES TO STOP smoking_status OXMIS observation
T5092SA SMOKING WANTS TO STOP smoking_status OXMIS observation
T5093 SMOKER NON smoking_status OXMIS observation
T5093N SMOKED NEVER smoking_status OXMIS observation
T5094F SMOKER IN FAMILY smoking_status OXMIS observation
T5094FS FATHER SMOKES smoking_status OXMIS observation
T5094MS MOTHER SMOKES smoking_status OXMIS observation
T5094PR PASSIVE SMOKING RISK smoking_status OXMIS observation
T510 EXCESSIVE SMOKING smoking_status OXMIS observation
T510 HS HEAVY SMOKER (20-PLUS PER DAY) smoking_status OXMIS observation
T510 SE SMOKING EXCESSIVE smoking_status OXMIS observation
T510 SH SMOKER HEAVY (20-PLUS PER DAY) smoking_status OXMIS observation
T511 SMOKER MODERATE (LESS THAN 20 PER DAY) smoking_status OXMIS observation
T5112 SMOKER (20 PER DAY) smoking_status OXMIS observation
T5113 SMOKER (15 PER DAY) smoking_status OXMIS observation
T5114 SMOKER (10 PER DAY) smoking_status OXMIS observation
T5115 SMOKER (LESS THAN 10 PER DAY) smoking_status OXMIS observation
T5115M SMOKER MILD (5 OR LESS PER DAY) smoking_status OXMIS observation
T5116 SMOKER(OCCASIONAL) smoking_status OXMIS observation
T5117 SMOKER (30 PER DAY) smoking_status OXMIS observation
T512 SMOKER PIPE smoking_status OXMIS observation
T513 SMOKER CIGARS smoking_status OXMIS observation
Y060 J1 STOP SMOKING GROUP smoking_status OXMIS observation
Y060 JJ CLINIC ANTI-SMOKING smoking_status OXMIS observation
Y060 KA SMOKING CLINIC smoking_status OXMIS observation
Y0601JJ CLINIC ANTI-SMOKING ATTENDANCE smoking_status OXMIS observation
Y0601KA SMOKING CLINIC ATTENDANCE smoking_status OXMIS observation

API

To Export Phenotype Details:

Format API
XML site_root/api/v1/public/phenotypes/PH621/version/1242/detail/?format=xml
JSON site_root/api/v1/public/phenotypes/PH621/version/1242/detail/?format=json
R Package

# Download here

library(ConceptLibraryClient)


# Connect to API

client = connect_to_API(public=TRUE)


# Get details of phenotype

details = get_phenotype_detail_by_version('PH621', '1242', api_client=client)

To Export Phenotype Code List:

Format API
XML site_root/api/v1/public/phenotypes/PH621/version/1242/export/codes/?format=xml
JSON site_root/api/v1/public/phenotypes/PH621/version/1242/export/codes/?format=json
CSV site_root/phenotypes/PH621/version/1242/export/codes/
R Package

# Download here

library(ConceptLibraryClient)


# Connect to API

client = connect_to_API(public=TRUE)


# Get codelists of phenotype

codelists = get_phenotype_code_list('PH621', '1242', api_client=client)

Version History

Version
ID
Name Owner Publish date
1242 Smoking Status ieuan.scanlon 2021-10-06 currently shown

Export - export all codes into a csv file/JSON/XML for the current phenotype version.

Print - Print page.