Primary outcome measures

For the purposes of the main analyses, outcomes commonly used in epidemiological research were derived. The mean of the second and third readings of systolic blood pressure and diastolic blood pressure in millimeters of mercury (mmHg) were used. For grip strength, the maximum of the four readings in kilograms (kg) was used. For lung function, the maximum forced expiratory volume in 1 second (FEV₁) and forced vital capacity (FVC) in millilitres (ml) from the highest quality readings (quality A or B) were used. Quality grade A was when 3 or more acceptable tests were achieved with repeatability within 100 ml, and B when 3 acceptable tests were achieved with repeatability within 150 ml, as per ATS/ERS criteria [6].