Introduction and objectives Sarcoidosis can significantly affect a patient’s quality of life (QOL). The St George’s Respiratory Questionnaire (SGRQ), a measure of respiratory-related quality of life,¹ correlates in cross-sectional studies with pulmonary function,² 6 MWD, organ involvement, duration of disease, and anti-inflammatory treatment in sarcoidosis. It is not known if the SGRQ is sensitive to changes in sarcoidosis severity over time.

We aimed to evaluate the relationship between SGRQ and commonly used markers of sarcoidosis severity and progression in a prospective longitudinal study.

Methods In a single site prospective observational study of patients with pulmonary sarcoidosis, patients were invited to attend for assessment every two months for 1 year. Assessments included lung function tests, chest x-ray, blood analyses, and QOL questionnaires. Linear mixed effects modelling (IBM SPSS Statistics) was used to evaluate the relationships between SGRQ and other markers over time.

Results 23 patients were recruited to the study; 19 completed the 1 year observational period. Mean age was 52.6 years (SD 8.1) and 57% were male.

There were strong longitudinal statistical relationships between the total SGRQ score and its three individual domains (symptoms, activity, and impact) and FEV1, FVC, serum ACE activity, blood lymphocyte count, and chest x-ray stage (p<0.01).

Conclusion SGRQ correlates well with markers of sarcoidosis, and tracks with changes over time. These findings support a larger study of the longitudinal construct validity of health-related quality of life tools in sarcoidosis.

References

1. Jones PW, Quirk FH, Baveystock CM, Littlejohns P. A self-complete measure of health status for chronic airflow limitation. The St. George’s Respiratory Questionnaire. Am Rev Respir Dis1992;145(6):1321–7.

2. de Boer S, Kolbe J, Wilsher ML. The relationships among dyspnoea, health-related quality of life and psychological factors in sarcoidosis. Respirology2014;19(7):1019–24.