Measuring psychosocial factors in health surveys using fewer items.

The present study investigated the possibility of reducing length of psychosocial scales, while maintaining validity, using easily manageable techniques. Data were collected 2003-2004 in a Swedish general population; n = 1007, ages 45-69, 50% women. Eight psychosocial scales were reduced from 6-20 to 3-7 items maintaining Cronbach's alpha >0.7 and correlation coefficients between full and reduced scales > 0.85. Relationships to biomarkers for inflammation, self-rated health and 8-year incidence of coronary heart disease showed no difference between full and reduced scales. It was possible, using these easily manageable methods, to reduce scale length without threatening validity for use in population surveys.