Background: Despite lower respiratory tract infection (LRTi) being the most common illness treated by doctors, no validated outcome measure to assess symptom duration and severity has been developed for patient self-completion.
Methods: As part of a randomized control trial researching management of acute LRTi, an easy self-completion diary was formulated and validated against the 'measure yourself medical outcome profile 2' (MYMOP2), an instrument previously validated in general practice.
Results: Spearman rank correlations of the diary profile versus MYMOP2 profile at baseline (r = 0.62), day 11 (r = 0.81) and change in score over time (r = 0.51) indicate that our diary correlates significantly with MYMOP2. The standardized response mean of the diary profile (mean change/SD change) = 1.48, indicating sensitivity to change.
Conclusion: This study shows that a simple symptom diary is internally reliable, valid and sensitive to change for acute LRTi. This instrument could be used as a routine measure of LRTi in further research in both primary and secondary care.