Exploratory factor analysis of self-reported symptoms in a large, population-based military cohort

<p>Abstract</p> <p>Background</p> <p>US military engagements have consistently raised concern over the array of health outcomes experienced by service members postdeployment. Exploratory factor analysis has been used in studies of 1991 Gulf War-related illnesses, and may increase understanding of symptoms and health outcomes associated with current military conflicts in Iraq and Afghanistan. The objective of this study was to use exploratory factor analysis to describe the correlations among numerous physical and psychological symptoms in terms of a smaller number of unobserved variables or factors.</p> <p>Methods</p> <p>The Millennium Cohort Study collects extensive self-reported health data from a large, population-based military cohort, providing a unique opportunity to investigate the interrelationships of numerous physical and psychological symptoms among US military personnel. This study used data from the Millennium Cohort Study, a large, population-based military cohort. Exploratory factor analysis was used to examine the covariance structure of symptoms reported by approximately 50,000 cohort members during 2004-2006. Analyses incorporated 89 symptoms, including responses to several validated instruments embedded in the questionnaire. Techniques accommodated the categorical and sometimes incomplete nature of the survey data.</p> <p>Results</p> <p>A 14-factor model accounted for 60 percent of the total variance in symptoms data and included factors related to several physical, psychological, and behavioral constructs. A notable finding was that many factors appeared to load in accordance with symptom co-location within the survey instrument, highlighting the difficulty in disassociating the effects of question content, location, and response format on factor structure.</p> <p>Conclusions</p> <p>This study demonstrates the potential strengths and weaknesses of exploratory factor analysis to heighten understanding of the complex associations among symptoms. Further research is needed to investigate the relationship between factor analytic results and survey structure, as well as to assess the relationship between factor scores and key exposure variables.</p

Cineradiography of the pharyngoesophageal segment in postlaryngectomy patients

The use of tracheoesophageal voice prostheses has gained wide acceptance in the field of vocal rehabilitation after total laryngectomy. In a randomized study with 3 arms, alaryngeal speech proficiency was assessed in 60 postlaryngectomy patients: 20 patients underwent primary unilateral pharyngeal myotomy, 21 patients underwent neurectomy of the pharyngeal plexus in addition to pharyngeal myotomy, and 19 patients did not undergo an additional surgical procedure. Pharyngoesophageal (PE) dynamics were examined during esophageal and tracheoesophageal speech. A single vibrating PE segment was seen in good alaryngeal speakers. Hypertonicity, spasm, strictures, and hypotonicity of the PE segment were correlated significantly with poor or moderate alaryngeal speech. Unilateral myotomy with or without unilateral neurectomy prevented hypertonicity or spasm of the PE segment. The acquisition of alaryngeal speech did not differ significantly between the 2 groups who had undergone an additional surgical procedure. Evaluation of anatomic and physiological factors may be helpful in subsequent clinical management to achieve effective alaryngeal speech.</p

Diagnosis of asthma and permitted use of inhaled beta2-agonists in athletes.

The prevalence of asthma and bronchial hyperreactivity has been reported to be higher in athletes than in the general population. This has also been related to reported asthma in order to obtain permitted use of b2-agonists, whose assumption in athletes is ruled by anti-doping regulations. The paper addresses the issue whether the recently established and evaluated rules of the International Olympic Committee on tests and procedures for diagnosis of asthma in athletes and permitted use of b2-agonists are consistent with an adequate diagnosis and management of asthma according to international guidelines

Levocetirizine improves health-related quality of life and health status in persistent allergic rhinitis.

SummaryBackgroundAllergic rhinitis is a chronic respiratory disorder with a detrimental impact on health-related quality of life (HRQOL) and health status. Enhancement and maintenance of patient function and well-being are therefore considered as essential.ObjectiveTo determine whether long-term treatment with levocetirizine 5mg improves HRQOL and health status in persistent allergic rhinitis (PER) patients assessed with RQLQ and SF-36 scales over a 6-month period.MethodsThe Xyzal® in PER Trial (XPERT™) was a multi-center, double-blind, parallel-group study. A total of 551 patients were randomized to receive levocetirizine 5mg or placebo once daily for 6 months and assessed for symptoms, HRQOL (Rhinoconjunctivitis Quality of Life Questionnaire: RQLQ) and health status (SF-36). Sensitivity of the RQLQ and SF-36 to disease severity was tested to ensure their suitability for use in PER patients. Treatment effect was assessed by means of repeated measures analyses.ResultsOver the 6-month treatment period, levocetirizine showed statistically significant improvements over placebo in HRQOL (P<0.001 for all RQLQ domains and overall scores) and health status (P⩽0.004 for SF-36 physical and mental summary scores; P<0.05 for all SF-36 scales). The relative improvement of levocetirizine over placebo exceeded the predefined clinically meaningful threshold of 30% for all RQLQ scores and the improvement from baseline was 3 times the established MID for RQLQ.ConclusionThe RQLQ and SF-36 could be used to measure HRQOL and health status in PER patients. Long-term treatment with levocetirizine provides sustained improvement of HRQOL and reduces disease burden in PER patients