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Questionnaire validation: Retrospective analysis of clinical data
Clinical Nutrition 34 (2015) 1283
Contents lists available at ScienceDirect
Clinical Nutrition journal homepage: http://www.elsevier.com/locate/clnu
Letter to the Editor
Questionnaire validation: Retrospective analysis of clinical data Dear Editor, Clinical Nutrition published our trial “Probiotic supplementation for respiratory and gastrointestinal illness symptoms in healthy physically active individuals” [1]. The main outcomes were that supplementation with Bifidobacterium animalis subp. lactis Bl-04™ and the combination of Lactobacillus acidophilus NCFM® and B. animalis subsp. lactis Bi-07™ (NCFM & Bi-07) for 150 days in healthy adults was associated with beneficial effects for upper respiratory tract illness (URTI). A key criticism of community-based studies such as ours is whether self-reported data reflects the diagnosis that would be made of the illness by a trained specialist esocalled physician verification. This concern is also reflected by regulatory bodies whom note that outcomes should be measured by generally accepted methods including validated questionnairebased assessments [2]. The Web-based respiratory illness questionnaire utilised in the 150 d clinical trial has a long history of use in research ([3,4]). In order to provide further confidence in the illness questionnaire as a diagnostic tool for determining URTI we completed a follow-up retrospective analysis of data collected during the study that identified participants who had visited a general practitioner (GP) while experiencing a URTI. A total of 103 participants who visited a GP were identified and contacted for consent to participate. Of the 103 participants there were 32 participants in the study whom provided details of their GP, with the remaining participants either not contactable, unable to remember the GP they visited or not willing to participate. The primary result from this work was that 18 GP's responded to the request for information, of which 11 made a primary diagnosis of URTI. Seven GP's indicated the person had visited them for another condition and not for an episode of URTI. Importantly, no GP's made a diagnosis on the respiratory symptoms presented that was different from that recorded as URTI on the questionnaire used in the study. While conducted on a limited sample size these results provide initial evidence of the reliability of the questionnaire for assessing URTI and confidence in the observation from our study that supplementation with Bl-04™ reduces the risk of URTI in healthy adults,
and supplementation with either Bl-04™ or NCFM® and Bi-07™ delays the median time to URTI by almost one month. References [1] West NP, Horn PL, Pyne DB, Gebski VJ, Lahtinen SJ, Fricker PA, et al. Probiotic supplementation for respiratory and gastrointestinal illness symptoms in healthy physically active individuals. Clin Nutr 2014;33:581e7. [2] EFSA, EFSA on Dietetic Products, Nutrition and Allergies (NDA). Guidance on the scientific requirements for health claims related to gut and immune function. EFSA J 2011:1984. [3] Fricker PA, Pyne DB, Saunders PU, Cox AJ, Gleeson M, Telford RD. Influence of training loads on patterns of illness in elite distance runners. Clin J Sport Med , 2005;15:246e52. [4] Cox AJ, Gleeson M, Pyne DB, Saunders PU, Callister R, Fricker PA. Respiratory symptoms and inflammatory responses to Difflam throat-spray intervention in half-marathon runners: a randomised controlled trial. Br J Sports Med 2010;44:127e33.
Nicholas P. West* Menzies Health Institute Queensland, Griffith University, QLD 4215, Australia David B. Pyne Menzies Health Institute Queensland, Griffith University, QLD 4215, Australia Physiology, Australian Institute of Sport, Canberra, ACT 2617, Australia Medical School, Australian National University, Canberra, ACT 2600, Australia Allan W. Cripps Menzies Health Institute Queensland, Griffith University, QLD 4215, Australia on behalf of the Probiotic Immune Research Consortium *
Corresponding author. E-mail address: n.west@griffith.edu.au (N.P. West).
http://dx.doi.org/10.1016/j.clnu.2015.07.020 0261-5614/© 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.
24 June 2015
Contents lists available at ScienceDirect
Clinical Nutrition journal homepage: http://www.elsevier.com/locate/clnu
Letter to the Editor
Questionnaire validation: Retrospective analysis of clinical data Dear Editor, Clinical Nutrition published our trial “Probiotic supplementation for respiratory and gastrointestinal illness symptoms in healthy physically active individuals” [1]. The main outcomes were that supplementation with Bifidobacterium animalis subp. lactis Bl-04™ and the combination of Lactobacillus acidophilus NCFM® and B. animalis subsp. lactis Bi-07™ (NCFM & Bi-07) for 150 days in healthy adults was associated with beneficial effects for upper respiratory tract illness (URTI). A key criticism of community-based studies such as ours is whether self-reported data reflects the diagnosis that would be made of the illness by a trained specialist esocalled physician verification. This concern is also reflected by regulatory bodies whom note that outcomes should be measured by generally accepted methods including validated questionnairebased assessments [2]. The Web-based respiratory illness questionnaire utilised in the 150 d clinical trial has a long history of use in research ([3,4]). In order to provide further confidence in the illness questionnaire as a diagnostic tool for determining URTI we completed a follow-up retrospective analysis of data collected during the study that identified participants who had visited a general practitioner (GP) while experiencing a URTI. A total of 103 participants who visited a GP were identified and contacted for consent to participate. Of the 103 participants there were 32 participants in the study whom provided details of their GP, with the remaining participants either not contactable, unable to remember the GP they visited or not willing to participate. The primary result from this work was that 18 GP's responded to the request for information, of which 11 made a primary diagnosis of URTI. Seven GP's indicated the person had visited them for another condition and not for an episode of URTI. Importantly, no GP's made a diagnosis on the respiratory symptoms presented that was different from that recorded as URTI on the questionnaire used in the study. While conducted on a limited sample size these results provide initial evidence of the reliability of the questionnaire for assessing URTI and confidence in the observation from our study that supplementation with Bl-04™ reduces the risk of URTI in healthy adults,
and supplementation with either Bl-04™ or NCFM® and Bi-07™ delays the median time to URTI by almost one month. References [1] West NP, Horn PL, Pyne DB, Gebski VJ, Lahtinen SJ, Fricker PA, et al. Probiotic supplementation for respiratory and gastrointestinal illness symptoms in healthy physically active individuals. Clin Nutr 2014;33:581e7. [2] EFSA, EFSA on Dietetic Products, Nutrition and Allergies (NDA). Guidance on the scientific requirements for health claims related to gut and immune function. EFSA J 2011:1984. [3] Fricker PA, Pyne DB, Saunders PU, Cox AJ, Gleeson M, Telford RD. Influence of training loads on patterns of illness in elite distance runners. Clin J Sport Med , 2005;15:246e52. [4] Cox AJ, Gleeson M, Pyne DB, Saunders PU, Callister R, Fricker PA. Respiratory symptoms and inflammatory responses to Difflam throat-spray intervention in half-marathon runners: a randomised controlled trial. Br J Sports Med 2010;44:127e33.
Nicholas P. West* Menzies Health Institute Queensland, Griffith University, QLD 4215, Australia David B. Pyne Menzies Health Institute Queensland, Griffith University, QLD 4215, Australia Physiology, Australian Institute of Sport, Canberra, ACT 2617, Australia Medical School, Australian National University, Canberra, ACT 2600, Australia Allan W. Cripps Menzies Health Institute Queensland, Griffith University, QLD 4215, Australia on behalf of the Probiotic Immune Research Consortium *
Corresponding author. E-mail address: n.west@griffith.edu.au (N.P. West).
http://dx.doi.org/10.1016/j.clnu.2015.07.020 0261-5614/© 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.
24 June 2015