The minimal clinically important difference in allergic rhinitis
Article first published online: 5 NOV 2009
© 2009 Blackwell Publishing Ltd
Clinical & Experimental Allergy
Volume 40, Issue 2, pages 242–250, February 2010
How to Cite
Barnes, M. L., Vaidyanathan, S., Williamson, P. A. and Lipworth, B. J. (2010), The minimal clinically important difference in allergic rhinitis. Clinical & Experimental Allergy, 40: 242–250. doi: 10.1111/j.1365-2222.2009.03381.x
- Issue published online: 11 JAN 2010
- Article first published online: 5 NOV 2009
- Submitted 29 December 2008; revised 7 August 2009; accepted 9 September 2009.
- allergic rhinitis;
- Mini Rhinoconjunctivitis Quality of Life Questionnaire;
- minimal clinically important difference;
- peak nasal inspiratory flow;
- total nasal symptom score
Background When presented with results from clinical measurements or research findings, clinicians must first make an interpretation of their importance, not only in statistical terms, but also the ‘clinical importance’ given the size of the change observed. To do this, they require an understanding of the relationship between their outcome measures, and the patient's perception of change. The minimal clinically important difference (MCID) illustrates this relationship by calculating the smallest change in a given outcome that is meaningful to a patient. There are few reports of calculated MCIDs in the Rhinology literature.
Objective To calculate MCIDs for common subjective and objective outcome measures in allergic rhinitis (AR).
Methods Nine randomized, blinded, placebo-controlled clinical trials in intermittent and persistent AR (pooled subjects, n=204) were analysed using anchor- and distribution-based approaches, applying regression and meta-analysis techniques.
Results MCIDs were obtained for the Mini Rhinoconjunctivitis Quality of Life Questionnaire: 0.4 units, peak nasal inspiratory flow: 5 L/min and total nasal symptoms score: 0.55 units. Nasal NO measurement changes had no correlation with patient perceptions of benefit.
Conclusion Estimates of MCIDs were obtained for common subjective and objective rhinological outcomes. MCIDs can and should be applied by physicians interpreting research findings, as well as researchers reporting their findings. We can then be confident that our changes in practice will be of perceptible benefit to the patient.
Cite this as: M. L. Barnes, S. Vaidyanathan, P. A. Williamson and B. J. Lipworth, Clinical & Experimental Allergy, 2010 (40) 242–250.