Respiratory symptoms and mortality in four general population cohorts over 45 years

Respir Med. 2020 Aug-Sep:170:106060. doi: 10.1016/j.rmed.2020.106060. Epub 2020 Jun 23.


Objective: This study assessed the association between respiratory symptoms and mortality in four cohorts of the general population in Norway aged 15-75 years and in selected subgroups in the pooled sample.

Methods: The study comprised 158,702 persons, who were drawn randomly from the Norwegian population register. All subjects received a standardized, self-administered questionnaire on 11 respiratory symptoms between 1972 and 1998, with follow-up of death until December 31, 2017. Analyses were performed on 114,380 respondents.

Results: The hazard of death was closely associated with sex, age, and education. The hazard ratios (HR) for death and the 95% confidence intervals (CI) by risk factors were similar in the four cohorts. After adjustment for demographic and environmental, modifiable factors, the HR for death was 1.90 (95% CI 1.80-2.00) for breathlessness score 3, 1.28 (1.21-1.37) for cough/phlegm score 5 and 1.09 (1.05-1.14) for attack of breathlessness/wheeze score 2 compared to the referent (no symptom), respectively. The cough/phlegm score was associated with death in current smokers but not in never smokers or ex-smokers. Breathlessness score was associated with death in men and women.

Conclusion: Among persons aged 45-75 years, respiratory symptoms were significant predictors of all cause mortality. Education and smoking habits influenced only the associations between coughing and mortality. The associations were independent of study sites.

Keywords: Cohort study; Men and women; Mortality; Respiratory symptoms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Aged
  • Cause of Death
  • Cohort Studies
  • Cough / mortality
  • Dyspnea / mortality*
  • Educational Status
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Norway / epidemiology
  • Respiratory Sounds
  • Risk Factors
  • Sex Factors
  • Surveys and Questionnaires*
  • Symptom Assessment / methods*
  • Time Factors
  • Young Adult