1. Lynn Josephs, David Culliford, Matthew Johnson, Mike Thomas
Current smoking status and its relationship to COPD outcomes: an observational cohort study using routine data in the Hampshire Health Record.
Lynn Josephs, David Culliford, Matthew Johnson, Mike Thomas
Department of Primary Care and Population Sciences and NIHR CLAHRC Wessex Methodological Hub, University of Southampton, UK.
Contact:

2. Study Background Smoking accelerates decline in FEV1 in COPD
Smoking cessation reduces this accelerated decline, especially early in the disease
Less is known of relationship to clinical outcomes

3. Study Aims Quantify current smoking status
Relationship smoking status to outcomes over 3y
All-cause mortality
Respiratory-cause hospital admissions (ICD-10 codes)
Respiratory-cause emergency department (ED) attendances

4. The data - HHRA Retrospective observational study
Individual patient-anonymised data held in the Hampshire Health Record Analytical database (HHRA)
Routine 1⁰ and 2⁰ care data
>140 practices
>1.4 million patients

5. Methods: Patients
Identified a prevalent cohort with a practice diagnosis of COPD as at 31/12/10 (Read Codes)
Quantified current smoking status:
Active smokers
Ex-smokers
Never smokers
Age, sex, socio-economic deprivation (IMD), BMI, FEV1 %predicted, FEV1/FVC %, comorbidities
Described age, sex, socio-economic deprivation (IMD), BMI, FEV1 %predicted, FEV1/FVC, comorbidities (18 diseases)

6. COPD cohort
16,479 patients (male 53.7%), mean (SD) age (11.1) years
Smoking status: available for 97.4% of cohort (missing in 434 patients)
Active smokers: 6,138 (37.2%)
Ex-smokers: 9,515 (57.7%)
Never smokers: 392 (2.4%)

7. Patient characteristics and smoking
Total cohort
Active smokers
Ex-smokers
Never smokers
Sex (male), n (%)
8847 (53.7)
3162 (51.5)
5319 (55.9)
135 (34.4)
Age years, mean (SD)
70.1 (11.1)
65.6 (10.9)
72.8 (10.1)
75.2 (12.9)
IMD rank decile, median (IQR)
6 (3-9)
(3-8)
6 (2-9)
FEV1 %predicted, mean (SD)
60.7 (20.1)
60.4 (19.3)
60.7 (20.6)
65.7 (23.9)
FEV1/FVC %, mean (SD)
59.6 (14.9)
59.1 (14.5)
59.7 (15.1)
64.5 (16.1)
BMI Kg/m², mean (SD)
27.2 (6.0)
26.3 (6.2)
27.7 (5.8)
26.5 (5.5)
Nº comorbidities, mean (SD)
2.6 (1.7)
(2.8)
2.8 (1.8)
2.8 (1.7)

8. Comorbidities 90.7% patients had one or more pre-existing comorbidity
anxiety and/or depression
bronchiectasis
cerebrovascular disease
chronic kidney disease
connective tissue disease
diabetes mellitus
gastro oesophageal reflux
heart failure
hyperlipidaemia
hypertension
ischaemic heart disease
lung cancer
obstructive sleep apnoea
osteoporosis
peripheral vascular disease
rhino-sinusitis
asthma
dementia
≥1 pre-existing comorbidities in 90.7% cohort:
;;;;;;;;;;;;;;;; e;

9. Outcomes and smoking (total cohort)
Active smokers
Ex-smokers
Never smokers
Deaths n (%)
2101 (12.7)
663 (10.8)
1342 (14.1)
63 (16.1)
Number (%) ≥1 hospitalisations
2909 (17.7)
1086 (17.7)
1705 (17.9)
64 (16.3)
Number (%) ≥1 ED attendances
1581 (9.6)
670 (10.9)
851 (8.9)
26 (6.6)

10. Number (%) with ≥1 admission
Odds ratios (95% CI) for each outcome in each smoking category adjusted for all measured variables (n=13,220)
Outcomes
Number (%) of deaths
Number (%) with ≥1 admission
Number (%) with ≥1 ED attendance
Univariate
Adjusted
Current
Smokers (n=5015)
1.00
(reference)
Ex-smokers
(n=7947)
1.36*
( )
0.88*
( )
1.02
( )
0.81*
( )
0.80*
( )
( )
Never
smokers
(n=258)
1.58*
( )
0.88
( )
0.91
( )
0.66*
( )
0.58*
( )
0.71
( )

11. Conclusions
After adjusting for confounders, current ex-smokers had significantly lower odds of all 3 adverse outcomes compared with active smokers
This highlights the importance of effective smoking cessation support
The small numbers of never smokers also appear to have a more benign prognosis (likely to be a heterogeneous group). …

12. Acknowledgements
The research team would like to thank NHS South, Central and West Commissioning Support Unit and the Hampshire Health Record Information Governance Group for their support, and for the provision of access to HHRA data.