Good Test-retest Reproducibility Research Articles

Validity, reliability, and responsiveness of a new short Visual Simplified Respiratory Questionnaire (VSRQ©) for health-related quality of life assessment in chronic obstructive pulmonary disease

The Visual Simplified Respiratory Questionnaire (VSRQ) was designed to assess health-related quality of life (HRQoL) in patients with chronic obstructive pulmonary disease (COPD). It contains eight items: dyspnea, anxiety, depressed mood, sleep, energy, daily activities, social activities and sexual life. Psychometric properties were assessed during a clinical trial that evaluated the impact of tiotropium on HRQoL of COPD patients. These included the determination of structure, internal consistency reliability, concurrent validity with the St George's Respiratory Questionnaire (SGRQ), test - retest reliability, clinical validity and responsiveness to change over two weeks. Minimal important difference (MID) was calculated; cumulative response curves (CRC) were based on the dyspnea item. Psychometric analyses showed that VSRQ structure was unidimensional. The questionnaire demonstrated good internal consistency reliability (Cronbach's alpha = 0.84), good concurrent validity with SGRQ (Spearman = -0.70) and clinical validity, good test-retest reproducibility (ICC = 0.77), and satisfactory responsiveness (standardized response mean = 0.57; Guyatt's statistic = 0.63). MID was 3.4; CRC median value of the 'minimally improved' patients was 3.5. In conclusion, VSRQ brevity and satisfactory psychometric properties make it a good candidate for large studies to assess HRQoL in COPD patients. Further validation is needed to extend its use in clinical practice.

Characterization of a novel model of tonic heat pain stimulation in healthy volunteers

The vast majority of the experimental pain studies have used acute, phasic heat stimuli to investigate the neurobiological mechanisms of pain. However, the validity of these models for understanding clinical forms of pain is questionable. We here describe the characteristics of a model of prolonged tonic heat pain stimulation and compared the responses on this test with other measures of pain. In 58 normal volunteers, we applied a 7-min lasting contact heat stimulation of 47 °C to the upper leg while participants constantly rated their pain. Average pain rating during the 7-min period was 6.2 ± 0.4, females scoring higher than men (7.4 ± 0.5 vs. 5.2 ± 0.5; p < 0.005). Pain ratings showed a steady increase during the first half of the stimulation period after which they stabilized. A strong interindividual variability was observed in the time profiles of the pain ratings over the course of the 7-min stimulation period. The model showed a good test–retest reproducibility. Tonic heat pain ratings only correlated moderately with the pain threshold while stronger correlations were observed with pain tolerance and ratings of suprathreshold phasic heat pain. We conclude that the tonic heat model is a suitable model that can be applied without excessive discomfort in the majority of subjects and offers a valuable addition to the armamentarium of experimental pain models. The model can be particularly suitable for brain imaging receptor binding studies which require long stimulation periods.

Measuring Edema in Irradiated Head and Neck Cancer Patients

Edema is a common side effect of radiotherapy for head and neck cancer. Systems have been developed to record and monitor changes that occur after radiotherapy. These lack the sensitivity to record edema in specific laryngo-pharyngeal structures. The aim of this study was to develop a rating scale to measure edema in the larynx and pharynx. This was an exploratory study to develop a new measure, with the help of an expert panel, assessing interrater and intrarater reliability. A consensus group developed the rating scale. Eleven structures and 2 spaces were identified as areas sensitive to the development of edema. The terms no, mild, moderate, and severe were used to describe the degrees of edema. The scale was piloted and then tested for interrater and intrarater reliability on 5 speech and language therapists. They viewed 25 nasendolaryngoscopic images (23 patients who had had radiotherapy and 2 healthy volunteers). The images were rated with the scale. This process was repeated 1 week later. Images were taken from patients with oral, oropharyngeal, nasopharyngeal, or laryngeal cancer. All had had radiotherapy or chemoradiotherapy. All raters were experienced in viewing larynges via nasendolaryngoscopy. The interrater reliability for scoring the edema rating scale was moderate (weighted kappa, 0.54). Lower levels of agreement were found for the tongue base, valleculae, pharyngeal walls, and anterior commissure. The intrarater reliability was very good (weighted kappa, 0.84). The edema rating scale can be scored with very good test-retest reproducibility and moderate levels of agreement between clinicians. Modifications to the method are suggested to increase interrater reliability.

Test-Retest Reproducibility of the Exercise Treadmill Examination in Lumbar Spinal Stenosis

To provide further validation of the treadmill test by assessing its "test-retest" reproducibility. In this prospective study, 28 patients with severe lumbar spinal stenosis underwent exercise treadmill testing, first at a walking speed of 1.2 mph and then at the patient's preferred walking speed. All patients had a second treadmill examination or "retest." No treatment intervention was performed between the initial test and the retest. Time to first symptoms (TFS) and total ambulation time (TAT) were measured. Differences between the baseline examination and the retest examination were assessed by using the concordance correlation coefficient (CCC) as well as graphically. There was good reproducibility between baseline test and retest results for all 4 end points: 1.2 mph, TFS (CCC = 0.90); 1.2 mph, TAT (CCC = 0.89); preferred walking speed, TFS (CCC = 0.98); and preferred walking speed, TAT (CCC = 0.96). The median difference between trials was not significantly different from zero for any of the 4 outcomes. Exercise treadmill testing has good test-retest reproducibility. There was no learning phenomenon associated with the test procedure. The study further validates the clinical utility of exercise treadmill testing in patients with lumbar spinal stenosis and neurogenic claudication.