Associations between type A behaviour pattern and psychological distress : 28 years of follow-up of the Oslo Study 1972/1973.

OBJECTIVE: To investigate the relationships between type A behaviour pattern (TABP) and psychological distress measured in middle aged men participating in two surveys 28 years apart. DESIGN AND
SUBJECTS: Men residing in Oslo and born in 1923-1952 (all men aged 40-49 years and 7% of those aged 20-39 years--30,016 altogether) were invited to a cardiovascular screening in 1972/1973--asking about risk factors, symptoms and diseases. All the 17,972 participants were also asked questions about TABP (two items) and psychological distress (one item). Of the original invited cohort, those who still lived in Oslo or its vicinity in 2000 were invited to a new health examination carried through by similar procedures. Among other questions the participants answered ten items about psychological distress (Hopkins Symptoms Checklist: HSCL-10). Altogether 7,393 men participated in both surveys.
RESULTS: In 1972/1973 almost 57% of those participating twice considered themselves as a person who stresses himself and chooses high speed and at the same time denied that they rather preferred a tranquil and quiet life--a combination of answers defined as type A behavior pattern. The corresponding TABP in 2000, when most of the men were retired, was 27%. A confirmatory factor analyses based on questions asked in 2000, verified that the HSCL/distress items reflected one underlying latent factor, and that this was a different factor than the one reflected in the two TABP items. The cross-sectional association between TABP and distress in 1972/1973 was highly significant (P < 0.001)--the odds ratio for psychological distress adjusted for background variables was 2.23 (95% confidence interval 1.98, 2.50). The corresponding association in 2000 showed a higher mean HSCL-10 score and a higher proportion with HSCL-score >or=1.85 in men with TABP compared with men without (P < 0.001 and P < 0.05, respectively), but the odds ratio in 2000 was lower than the result 28-years earlier. When those reporting psychological distress in 1972/1973 were excluded, TABP in 1972/1973 predicted psychological distress (HSCL-10) in the follow-up survey when adjusted for background variables (P < 0.05) using structural equation modelling.
CONCLUSION: Type A behaviour pattern and psychological distress reflect two different latent factors. TABP seems to be associated with psychological distress, both cross-sectionally and prospectively. This knowledge permits early detection of individuals who have a higher probability of experiencing psychological distress over a considerable period of time.