Table 1

Sociodemographic, pulmonary and psychological variables of study participants aged 65 or above (Singapore Longitudinal Ageing Study, SLAS)

N%N%Significant testp Value
 Male5842.611240.7χ2=0.138, df=10.710
Age (years, M±SD)73.19±5.8771.23±5.47t=3.3280.001
 Chinese12189.024187.6χ2=0.154, df=10.694
 Never smoker7757.621177.3χ2=20.59, df=3<0.001
 Past smoker2921.64115.0
 Current smoker<10 cigarettes daily1813.4124.4
 Current smoker≥10 cigarettes daily107.593.3
Number of chronic diseases2.60±1.301.65±1.25t=7.096<0.001
Number of negative life events0.67±0.980.74±1.11t=0.6090.543
Life event stress score1.02±1.711.12±1.78t=0.5250.600
Postbronchodilator FEV11.42±0.501.75±0.52t=6.185<0.001
CFQ score38.0±9.2138.8±9.83t=0.7330.464
MMSE score26.4±3.2627.4±3.11t=3.0900.002
GDS depression score1.13±2.040.84±1.69t=1.4870.138
GDS≥575.282.9χ2=1.349, df=10.245
SF-36 PCS44.6±9.0447.1±7.21t=2.7260.007
SF-36 MCS54.9±7.8355.1±6.68t=0.3530.724
  • Figures in table denote mean±SD or number and %.

  • Smoker is defined as smoking≥10 cigarettes daily.

  • COPD, chronic obstructive pulmonary disease; CFQ, Cognitive Failures Questionnaire; GDS, the Geriatric Depression Scale;  MMSE, mini-mental state examination; SF-36 MCS, 36-Item Short-Form Mental Health Component Summary; SF-36 PCS, 36-Item Short-Form Physical Health Component Summary.