A prospective population study in Renfrew and Paisley, Scotland, found that lower forced expiratory volume in one second (FEV₁) is associated with increased mortality risk in both men and women. The study followed 7058 men and 8353 women aged 45-64 years for 15 years, finding that those with lower FEV₁ had higher risks of death from all causes, ischaemic heart disease, lung cancer, stroke, and respiratory disease. The relative hazard ratios for all-cause mortality were 1.92 for men and 1.89 for women in the lowest fifth of FEV₁ distribution. These associations remained significant even after adjusting for age, smoking, blood pressure, cholesterol, BMI, and social class. The study also found that FEV₁ was a strong predictor of mortality in lifelong non-smokers, with similar risk gradients for all causes of death except cancer. The results suggest that impaired lung function is a major indicator of mortality risk for a wide range of diseases. FEV₁ should be considered as part of health assessments for middle-aged patients, with smokers with reduced FEV₁ being a priority group for smoking cessation advice. The study highlights the importance of FEV₁ as a marker of respiratory function and its role in predicting mortality risk. Smoking cessation is currently the best way to slow the decline in FEV₁, and smokers with reduced FEV₁ should be targeted for advice to stop smoking. The study also emphasizes the need for FEV₁ to be included in health assessments for middle-aged patients to improve overall health outcomes.A prospective population study in Renfrew and Paisley, Scotland, found that lower forced expiratory volume in one second (FEV₁) is associated with increased mortality risk in both men and women. The study followed 7058 men and 8353 women aged 45-64 years for 15 years, finding that those with lower FEV₁ had higher risks of death from all causes, ischaemic heart disease, lung cancer, stroke, and respiratory disease. The relative hazard ratios for all-cause mortality were 1.92 for men and 1.89 for women in the lowest fifth of FEV₁ distribution. These associations remained significant even after adjusting for age, smoking, blood pressure, cholesterol, BMI, and social class. The study also found that FEV₁ was a strong predictor of mortality in lifelong non-smokers, with similar risk gradients for all causes of death except cancer. The results suggest that impaired lung function is a major indicator of mortality risk for a wide range of diseases. FEV₁ should be considered as part of health assessments for middle-aged patients, with smokers with reduced FEV₁ being a priority group for smoking cessation advice. The study highlights the importance of FEV₁ as a marker of respiratory function and its role in predicting mortality risk. Smoking cessation is currently the best way to slow the decline in FEV₁, and smokers with reduced FEV₁ should be targeted for advice to stop smoking. The study also emphasizes the need for FEV₁ to be included in health assessments for middle-aged patients to improve overall health outcomes.