Two short instruments measuring quality of life in survivors of a myocardial infarction

The aim of this study was to validate the use of short, generic, quality-of-life (QoL) questionnaires in a population of myocardial infarction survivors. The feasibility, reliability, and validity of two short questionnaires (the MOS-24 and the COOP/WONCA charts) were evaluated and compared with a long questionnaire (the Sickness Impact Profile). The study population consisted of 99 myocardial infarction survivors some years after the event and 101 referents without a history of heart or brain infarction. The feasibility of the short questionnaires was good. Both instruments covered the most important domains of QoL, similar to the Sickness Impact Profile. In addition, the two short questionnaires measured "pain" and the MOS-24 also covered "vitality." The MOS-24 had a smaller floor effect than the COOP/WONCA charts. The MOS-24 was shown to be a reliable test. Both short instruments were able to detect between-group differences (especially MOS-24) although at different rates. Convergent validity of the MOS-24 was high compared with the COOP/WONCA charts. In contrast, the discriminant validity of the COOP/WONCA charts was better. The discriminant validity of the MOS-24 was, nevertheless, reasonable. In conclusion, both instruments are suitable for measuring the QoL of myocardial infarction survivors. The multi-item MOS-24 questionnaires however, is slightly preferable.