Priti Jhingran

The minimally important difference of the Asthma Control Test

BACKGROUND The Asthma Control Test (ACT) has been well validated, but a minimally important difference (MID) has not been established. OBJECTIVE We sought to identify an MID for the ACT. METHODS Data come from 4 independent samples of adult asthmatic patients. Distributional methods for determining the MID included 0.5 SD, 1 SEM, and 2 SEM. Anchor-based methods assessed the relationship of differences in ACT scores to (1) self-reported asthma severity, (2) asthma episode frequency in the past 4 weeks, (3) physician ratings of asthma control, (4) physician recommendation of a change in therapy, (5) FEV(1), (6) the risk over the next 12 months of excess short-acting beta-agonist use and exacerbations, and (7) patient-defined changes in asthma course over 3 months. RESULTS Four thousand one hundred eighteen patients completed the ACT. The 0.5 SD criterion for MID ranged from 2.03 to 2.45 points (mean, 2.2 points). The 1 SEM criterion ranged from 1.77 to 2.05 points (mean, 1.88 points), and the 2 SEM criterion ranged from 3.55 to 4.10 points (mean, 3.75 points). Differences in mean ACT scores across patient groups differing on criterion measures ranged from 1.06 to 5.28 points (mean, 3.1 points). Predictive analyses showed that a difference of 3 points on the ACT was associated with a subsequent 76% increased risk (95% CI, 73% to 79%) of excess short-acting beta-agonist use and a 33% increased risk (95% CI, 31% to 35%) of exacerbations. CONCLUSION The data support an MID for the ACT of 3 points.

Costs of care for irritable bowel syndrome Patients in a health maintenance organization

Abstract OBJECTIVES: The aims of this study were: 1) to determine the total costs of care and costs related to lower GI–related problems for patients who received a diagnosis of irritable bowel syndrome (IBS), and 2) to compare them to age- and sex-matched population controls and patients treated for inflammatory bowel disease (IBD) or gastroesophageal reflux disease (GERD). METHODS: Use and cost data were obtained through the computerized information systems of a large staff-model health maintenance organization on three groups of patients diagnosed in 1994 or 1995 with IBS, IBD, or GERD; and an age- and sex-matched control group of patients without any of these listed diagnoses. The IBS patient group was compared to the three comparison groups on components of total and IBS-related costs. RESULTS: Total costs of care for IBS patients were 49% higher than population controls during the year starting with the visit at which IBS patients were identified. In the index year, every component of total costs except inpatient care was significantly higher for IBS patients than for population controls. The costs of care for lower GI problems were significantly higher for patients with IBS than for population controls across a range of services. However, only 33% of the difference in total costs of care between IBS patients and population controls was due to lower GI–related services in the index year. In the subsequent years, lower GI–related services accounted for 18% and 20% of the total cost difference between IBS patients and population controls. The total costs of care as well as the components of costs of care were generally higher for IBD patients than for IBS patients, but were comparable for GERD and IBS patients. CONCLUSIONS: Patients with IBS show sustained increases in health care costs relative to population controls for both lower GI services and care unrelated to lower GI problems. However, the majority of the excess in health care costs resulted from medical care not directly related to lower GI problems.

Alosetron controls bowel urgency and provides global symptom improvement in women with diarrhea-predominant irritable bowel syndrome ☆

OBJECTIVES:Bowel urgency is one of the most bothersome symptoms for nonconstipated IBS patients. The efficacy of alosetron in control of bowel urgency and Global Improvement of IBS symptoms were evaluated in a multicenter double-blind, randomized, placebo-controlled study.METHODS:Female IBS patients with lack of satisfactory control of bowel urgency were randomized 2:1 to alosetron 1 mg twice daily or placebo treatment groups. The primary endpoint was the proportion of days with satisfactory control of bowel urgency during the 12-wk treatment period and 2-wk follow-up period. Secondary endpoints included IBS Global Improvement (responder defined as patient-reported moderate or substantial improvement in IBS symptoms) and improvements in bowel function (stool frequency, consistency, and sensation of incomplete evacuation).RESULTS:A total of 801 women were randomized to the alosetron (n = 532) or placebo groups (n = 269). Physicians classified 98% of patients with diarrhea-predominant IBS. Patients treated with alosetron had a significantly greater proportion of days with satisfactory control of urgency compared to placebo for the treatment period (73% vs 57%, p < 0.001). A significantly greater number of patients treated with alosetron were IBS Global Improvement responders compared to placebo at week 12 (76% vs 44%, p < 0.001). IBS Global Improvement responders had more days with satisfactory control of urgency at week 12 (88% vs 48%) as well as firmer stools, fewer stools/day, and fewer days with incomplete evacuation compared with nonresponders. Alosetron-treated patients showed improvements in bowel functions compared to placebo-treated patients. Constipation was the most commonly reported adverse event.CONCLUSIONS:Alosetron is effective at managing bowel urgency in women with diarrhea-predominant IBS. The IBS Global Improvement assessment correlated with improvements in bowel function and may be a useful tool in future IBS clinical trials.

Development and validation of the migraine-specific quality of life questionnaire

This paper describes the development and validation of a migraine‐specific quality‐of‐life instrument that is capable of measuring health‐related quality‐of‐life impairments attributed to migraine. Item selection, item reduction, and pretesting and finalization of items during the instrument development phase resulted in a total of 16 questions which were incorporated into the Migraine‐Specific Quality of Life Questionnaire (Version 1:0) (©1992 Glaxo Wellcome Inc). Three meaningful dimensions were hypothesized: Role Function‐Restrictive, Role Function‐Preventive, and Emotional Function. In the instrument validation phase, the Migraine‐Specific Quality of Life Questionnaire was mailed to 1109 migraine patients, providing a response rate of 45% (n=458). Initial psychometric evaluation of the questionnaire indicated that it possessed adequate reliability with Cronbachs alpha for the three dimensions ranging between 0.70 to 0.85. The Migraine‐Specific Quality of Life Questionnaire possessed adequate content and criterion validity. All but three items satisfied the test of construct validity. In conclusion, the Migraine‐Specific Quality of Life Questionnaire has acceptable psychometric properties and can be used to estimate the effect of migraine and its treatment on the patients health‐related quality of life.

Validity and reliability of the Migraine-Specific Quality of Life Questionnaire (MSQ version 2.1)

Objective.–To assess the scaling properties, reliability, and validity of the revised Migraine‐Specific Quality of Life Questionnaire (MSQ) (Version 2.1)

MSQ: Migraine-specific quality-of-life questionnaire. Further investigation of the factor structure

SummaryMSQ, the 16-item Migraine—Specific Quality—of—Life Questionnaire (Version 1.0), was developed by Glaxo Wellcome Inc. to assess the effect of migraine and its treatment on patients’ health—related quality of life (HR-QOL). The MSQ was hypothesised to measure 3 meaningful dimensions: (i) Role Function—Restrictive; (ii) Role Function—Preventive; and (iii) Emotional Function. The objective of this research was to further investigate the number of dimensions as well as the items contained in each dimension through principal components factor analysis of clinical trial data. Secondary objectives were to determine whether the factor structure changed in post—treatment visits compared with screening visits, to make recommendations for coding the MSQ when the patient did not have a migraine in the previous 4 weeks, and to modify the MSQ if so indicated by this research. Results supported the existence of 3 distinct factors which agreed strongly with the hypothesised dimensions. The analysis of post—treatment data suggested that the underlying factor structure of the MSQ varies as a result of treatment. Based on evaluations of the ‘did not have a migraine’ response, it was concluded that it be dropped from the MSQ. All these changes have been incorporated into MSQ (Version 2.0) which is being evaluated in studies to determine if its psychometric properties are different than the properties of the previous version.

Predicting risk of airflow obstruction in primary care: Validation of the lung function questionnaire (LFQ)

The Lung Function Questionnaire (LFQ) is being developed as a case finding tool to identify patients who are appropriate for spirometry testing to confirm the diagnosis of chronic obstructive pulmonary disease (COPD). The cross-sectional study reported herein was conducted to validate the LFQ, to identify item-response scales associated with the best accuracy, and to determine the impact on accuracy of the addition of another item on activity limitations (AL). Patients >or= 40 years old seen at 2 primary care offices completed the LFQ, a demographic questionnaire followed by spirometry. Of the 837 evaluable patients, 18.6% had airflow obstruction (forced expiratory volume in 1 s/forced vital capacity [FEV(1)/FVC] < 0.70). The 5 items (age, wheeze, dyspnea, smoking, and cough) previously identified in initial LFQ development predicted airflow obstruction and showed good evidence of screening accuracy. Screening accuracy was significantly better with 5-point ordinal item-response scales (78%) than binary (yes/no) item-response scales (74%)(p < 0.05). Screening accuracy was good regardless of whether airflow obstruction was defined as FEV(1)/FVC < 0.70 or FEV(1)/FVC < 0.70 and FEV(1) < 80% of predicted. Based on <or=18 was selected to suggest presence of airflow obstruction with area under the receiver operating characteristic curve 0.652; sensitivity 82.6%; specificity 47.8%; 54.3% correctly classified. While the specificity of LFQ is low, its high sensitivity suggests that it can serve to identify patients who should be further assessed using spirometry. Our results confirm the screening accuracy of the LFQ, a simple and effective tool to facilitate early recognition and diagnosis of COPD.

Validation of Irritable Bowel Syndrome Global Improvement Scale: An Integrated Symptom End Point for Assessing Treatment Efficacy

The Global Improvement Scale (GIS) assesses multiple irritable bowel syndrome (IBS) symptoms using a patient-defined 7-point Likert scale ranging from symptoms substantially worse to substantially improved. To evaluate the scale as an efficacy end point, data were collected from two 12-week randomized, double-blind, placebo-controlled studies of female nonconstipated IBS patients. GIS responders were defined as having substantial or moderate improvement in IBS symptoms. GIS responders had more days with satisfactory control of urgency, firmer stools, fewer stools per day, and fewer days with incomplete evacuation compared to nonresponders. Substantially more GIS responders (90% and 89% in studies 1 and 2, respectively) were satisfied or very satisfied with their treatment overall compared to nonresponders (13% and 11%) ( r = 0.8 in both studies). GIS responders had greater satisfaction with medication relief of pain and discomfort and the time needed to return to usual activities. Favorable correlations between GIS and work and nonwork productivity losses were observed. Correlation of the GIS measure with IBS clinical end points establishes the validity of the GIS for measuring improvement in IBS symptoms. The GIS may be useful in assessing the efficacy of IBS interventions in future clinical trials.

Cost-effectiveness of fluticasone propionate/salmeterol (500/50 μg) in the treatment of COPD

OBJECTIVE We examine the lifetime cost-effectiveness of treatment with fluticasone propionate/salmeterol (500/50 microg) compared with no maintenance treatment in COPD in the US. METHODS A decision-analytic model was developed to estimate lifetime costs and outcomes associated with fluticasone propionate/salmeterol 500/50 microg treatment, salmeterol 50 microg, and fluticasone propionate 500 microg compared to no maintenance treatment in treating COPD from a third-party US payer perspective. The patient population was similar to that of the TORCH clinical trial. Model structure and inputs were obtained from published literature and clinical trial data. All costs are presented in 2006 US dollars. Outcomes included cost per life year (LY) saved and cost per quality-adjusted life year (QALY) gained. Costs and outcomes were discounted at 3% annually. Univariate and multivariate sensitivity analyses were conducted to assess model robustness. RESULTS Compared to no maintenance treatment, treatment with fluticasone propionate/salmeterol 500/50mug results in a lifetime incremental cost-effectiveness ratio (ICER) of

Patient satisfaction with alosetron for the treatment of women with diarrhea-predominant irritable bowel syndrome.

33,865/QALY. Treatment with salmeterol 50 microg was found to have an ICER of