What are the health-related quality of life SF-6D scores of the smokers with or without respiratory symptoms, and those who have stopped smoking?

Problem

There are around 10% of patients attending Hong Kong public primary care clinics actively smoking. People with a history of smoking commonly present with respiratory symptoms in primary care. Primary care clinicians therefore share the responsibility to tackle the low annual quit rate. International studies showed heavy active smokers had reduced health related quality of life (HRQoL), when compared with patients who have already stopped smoking. Understanding differences in HRQoL score among patients with different status of smoking could potentially motivate active smokers to consider smoking cessation.

Approach

This was a cross-sectional multi-center survey. Seven hundred and thirty-one people from 5 public primary care clinics, aged ≥ 30, with a history of smoking (ever smoked ≥ 100 cigarettes) and no previous history of chronic respiratory illness completed the study (response rate 97%). The study consists of office spirometry and three questionnaires: (1) the Breathlessness, Cough, and Sputum Scale (BCSS scale, score 0= no symptoms to 12 = most severe symptoms), (2) Short-Form 6 Dimensions (SF-6D) (score ranges 0=vegetation status to 1 = prefect health) and (3) clinical and personal parameters.

Findings

Most of the subjects were men (92.5%) with relatively older age (mean 62.2). The ratio of current smokers to past smokers was 0.93. One Hundred and fifty-three (21.1%) were light smokers (< 10 cigarettes per day (cpd)), 256 (35.3%) were moderate smokers (10-19 cpd) while 317 (43.4%) were heavy smokers (≥20 cpd). More than half of them (54.2%) reported mild respiratory symptoms (mean BCSS score 0.95, S.D. 1.12). They could present of other medical symptoms or problems. The most common symptoms was sputum (45.1%) followed by cough(34.2%) and breathlessness (6.0%). The SF-6D overall score was 0.850 ± 0.106(score ranges 0=vegetation status to 1 = prefect health). The subjects reported significantly lower SF-6D score when they had breathlessness (0.752 ± 0.138; p =<0.001); cough (0.836±0.107; p = 0.007); or sputum (0.838 ± 0.115; p = 0.004). There was no statistically significant difference of the SF-6D score among light smokers (0.851±0.106), moderate smokers (0.844±0.109) and heavy smokers (0.855±0.107). In the linear regression model, the BCSS score (B = -0.018, 95% C.I. -0.024 to -0.011, p < 0.001) were negatively associated with SF-6D values, while men had higher score when compared with women (B = 0.034, 95% C.I. 0.004 to 0.064, p = 0.025). The presence of airflow limitation in spirometry, body mass index, number of comorbidity, age, educational level, occupation, were not associated with the SF-6D values.

Consequences

Primary care patients with a history of smoking commonly have mild respiratory symptoms, which is associated with reduced HRQoL. Primary care clinicians could use the opportunity to motivate smokers for smoking cessation.