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Use of the single‐item Patient Global Impression‐Severity scale as a self‐reported assessment of insomnia severity
Abstract
We evaluated a single‐item Patient Global Impression‐Severity (PGI‐S) scale for assessing insomnia severity during the clinical development programme for suvorexant. The analyses used data from two randomised, double‐blind, placebo‐controlled, 3‐month, Phase III clinical trials of suvorexant in patients with Diagnostic and Statistical Manual of Mental Disorders IV criteria insomnia. Patients assessed insomnia severity during the previous week using the PGI‐S, a one‐item questionnaire containing six response options ranging from 0 (none) to 5 (very severe), at baseline and at Week 2, and Months 1, 2, and 3 after randomisation. The seven‐item Insomnia Severity Index (ISI) and other subjective and objective assessments were also completed by patients. PGI‐S responses were compared primarily with the ISI using descriptive statistics and correlations. The PGI‐S demonstrated favourable measurement characteristics (validity, reliability, responsiveness and sensitivity). PGI‐S scores decreased from baseline to Month 3 in a similar pattern to the ISI total score, and the Spearman correlation coefficient between PGI‐S and the ISI was .73. An improvement of ≥2 points on the PGI‐S defined a treatment responder, based on comparison to the ISI definition of a responder (improvement of ≥6 points). Our present findings suggest that the PGI‐S is a simple but valid, reliable, responsive, sensitive, and meaningful patient‐reported assessment of insomnia severity. The PGI‐S may be particularly useful as a companion outcome to sleep monitoring using wearable sleep devices or smartphones in at‐home settings.
... The items can be rated from 0 to 4 (0 = no problem; 4 = very severe problem), with a total score ranging from 0 to 28. The total score can be interpreted as follows: absence of insomnia (0-7), subthreshold insomnia (8)(9)(10)(11)(12)(13)(14), moderate insomnia (15)(16)(17)(18)(19)(20)(21), and severe insomnia (22-28). Previous research has identified at least two clinically important thresholds for the ISI total score: Morin et al. proposed a change of −8.4 points as a moderate improvement, while Yang et al. proposed a change of −6 points as a minimally clinically important difference [6,7]. ...
... Patient Global Impression-Insomnia (PGI-I) provides a self-reported questionnaire assessing the patients' perception of a medication's effects on sleep after treatment compared with their sleep prior to treatment initiation [10]. Hence, the three PGI-I items are related to the benefit of study medication as perceived by patients: (i) Helped/Worsened Sleep, (ii) Increased/Decreased Time to Fall Asleep, and (iii) Increased/Decreased Total Sleep Time (TST). ...
Background
The Insomnia Severity Index (ISI) is a widely used measure of insomnia severity. Various ISI research findings suggest different factor solutions and meaningful within-individual change (MWIC) to detect treatment response in patients with insomnia. This study examined an ISI factor solution and psychometric indices to define MWIC in a robust patient sample from clinical trial settings.
Methods
We endeavored to improve upon previous validation of ISI by examining structural components of confirmatory factor analysis (CFA) models using two large, placebo-controlled clinical trials of lemborexant for insomnia. Using the best-fitting two-factor solution, we evaluated anchor-based, distribution-based and receiver operating characteristic (ROC) curve methods to derive an estimate of the MWIC.
Results
The model structure for the 7-item scale proposed in other research did not fit the observed data from our two lemborexant clinical trials (N = 1956) as well as a two-factor solution based on 6 items did. Using triangulation of anchor-based, distribution-based, and ROC methods, we determined that a 5-point reduction using 6 items best represented a clinically meaningful improvement in individuals with insomnia in our patient sample.
Conclusions
A 6-item two-factor scale had better psychometric properties than the 7-item scale in this patient sample. On the 6-item scale, a reduction of 5 points in the ISI total score represented the MWIC. Generalizability of the proposed MWIC may be limited to patient populations with similar demographic and clinical characteristics.
Supplementary Information
The online version contains supplementary material available at 10.1186/s41687-024-00744-6.
... Therefore, in this secondary analysis of data from a clinical efficacy study (Motion Sifnos) for the development of Tradipitant (a novel neurokinin-1 antagonist) for the treatment of motion sickness [14], we sought to assess the validity of the MSSS compared with the Patient Global Impression of Severity (PGI-S), a brief measure of symptom severity, and the MSAQ, a validated motion sickness scale. The PGI-S is a single-item, 5-point scale that evaluates the global severity of a given sickness or disease [15][16][17]. The MSAQ is a 16-item, 9-point questionnaire that evaluates motion sickness as a multidimensional construct and includes many of the variably experienced symptoms classified into the following factors: gastrointestinal, central, peripheral, and sopite-related. ...
Background
Motion sickness is characterized by nausea and vomiting among a constellation of symptoms. Symptom severity is dynamic and distressing. Most validated motion sickness scales are time-intensive and effortful, with alternative scales having uncertain performance or non-specific measures. A validated instrument allowing for facile, rapid assessment of core motion sickness symptom severity would therefore be valuable. We assessed the performance of the Motion Sickness Severity Scale (MSSS), a six-item questionnaire designed to measure real-time motion sickness symptoms.
Methods
MSSS construct validity was assessed as a secondary analysis of data from 63 healthy participants without antiemetic treatment in a clinical trial (Unique Identifier = NCT03772340) conducted to evaluate the safety and efficacy of Tradipitant—a novel neurokinin-1 receptor antagonist—in the treatment of motion sickness. Clinical outcome assessments included the MSSS, the Patient Global Impression of Severity (PGI-S), and the Motion Sickness Assessment Questionnaire (MSAQ). The performance of the MSSS through Pearson correlation coefficients, within-group analysis of variance, empirical cumulative distribution functions, and Kolmogorov-Smirnov tests.
Results
The MSSS correlated very highly with the PGI-S (r = 0.93, p-value<0.0001) and highly with the MSAQ (r = 0.83, p-value<0.0001). Mean MSSS scores between increasing PGI-S severity levels increased significantly in all four increments (None-to-Mild: p-value = 0.006, Mild-to-Moderate: p-value<0.0001, Moderate-to-Severe: p-value = 0.006, Severe-to-Very-Severe: p-value = 0.002). There were statistically significant differences in MSSS score distributions stratified by PGI-S severity level, with higher MSSS scores associated with higher PGI-S severity levels and lower MSSS scores associated with lower PGI-S severity levels.
Discussion
The MSSS is a valid instrument for the assessment of the core motion sickness symptoms and is reflective of global disease severity. Implementation of the MSSS and comparable simplified, short questionnaires in motion sickness research will provide rapid and accurate measures of disease severity. These measures will enable further elucidation of motion sickness as an illness and inform the development and evaluation of motion sickness therapies.
... The MWT is more commonly used in clinical trials. Global impressions [92][93][94][95] are used to assess how effective the tested treatment is by making a comparison before and after treatment (Table III). Generally, these global impressions are not used to evaluate the quality of wake, though they could potentially be used this way by choosing a customized topic that has to do with aspects of wake. ...
Excessive daytime sleepiness (EDS) is a complex symptom characterized by a strong urge to sleep during daytime accompanied by problems such as attention deficits, anxiety, and lower cognitive performance. The efficacy of treatments for EDS is determined by their ability to decrease sleepiness, and less attention has been given to the effects these compounds have on the quality of the wake itself. Hypocretin (HCRT; orexin) signalling is implicated in narcolepsy, and hypocretin receptor 2 (HCRTR2) agonists are in clinical trials for treating EDS in narcolepsy. Here, we review preclinical research to determine how HCRTR2 agonists may affect attention and anxiety compared with other EDS treatment strategies. We conclude that such compounds may improve not only the quantity but also the quality of wake, and we hope that they will create opportunities for more nuanced treatment strategies in narcolepsy.
Purpose
The Sleep Quality Scale (SQS) is a popular single-item measure of sleep quality that has been used in research and clinical settings. The aim of the current paper is to validate the SQS and provide a cutoff score.
Methods
We conducted two studies to validate the SQS and provide a cutoff score to simplify the interpretation of SQS scores. We collected data from 747 physicians and nurses working in Oman.
Results
In Study 1, conducted during the first two weeks of April 2020, a significant positive relationship was observed between the SQS and The World Health Organization Wellbeing Index (r. = 0.90) and a significant negative relationship was found with the Generalized Anxiety Disorder scale (r = .88) and the Intolerance of Uncertainty Scale-12 (r = .88). In Study 2, conducted between October 12 and November 19, 2020, we proposed a cutoff score for the SQS using the Insomnia Severity Index cutoff score of ≥ 10. The estimated area under the receiver operating characteristics curve was 0.881 (95% CI = 0.84–0.92). A cutoff score of ≤ 6 was identified with a sensitivity of 87.50 (95% CI = 0.78–0.94), and a specificity of 74.10 (95% CI = 0.67–0.81).
Conclusions
The findings of this study suggest that the single-item SQS is valid and an acceptable substitute for longer scales for initial assessment of sleep quality. The suggested cutoff value should help in easily classifying individuals into poor sleepers and good sleepers.
Objective/Background
Sleep disturbance is a common and underappreciated feature of diabetes and sleep may contribute to glycemic control in people with type 2 diabetes (T2D). We conducted a 3-month trial to examine the efficacy of suvorexant in improving sleep and health outcomes in people with suboptimally controlled T2D and insomnia.
Participants/Methods
This parallel, double-blind, randomized placebo-controlled trial was conducted using the sequential parallel comparison design (SPCD). Sixty-nine people with poorly controlled T2D (HbA1c ≥ 6.5) were randomized to placebo and/or suvorexant (10–20 mg). The primary outcome was subjective total sleep time (sTST), and secondary outcomes were Insomnia Severity Index (ISI) score and wake time after sleep onset (WASO). Exploratory outcomes included sleep efficiency, hemoglobin A1c (HbA1c), and C-reactive protein (CRP). Exploratory analyses were conducted on relationships between sleep and diabetes outcomes.
Results
There were no significant improvements in sTST (p = 0.27), ISI (p = 0.86), or WASO (p = 0.94) among participants taking suvorexant compared to placebo. There were also no significant changes in any of the exploratory endpoints. Improvements in sleep were associated with improvements in both objective (ie, HbA1c) and subjective (ie, Diabetes Distress Scale) measures of diabetes, as well as reductions in depressive symptoms, independent of treatment assignment.
Conclusion
The study did not find evidence that suvorexant is efficacious for insomnia in people with poorly controlled T2D. The associations of improved sleep with improvements in both diabetes-related metrics and depressive symptoms across groups highlight the importance of identifying and treating sleeping difficulties in this population.
CT Registration #
Nct03818581.
Background:
The Patient Global Impression of Severity (PGI-S) scale is a self-reported, single-item categorical scale which is increasingly used when assessing chronic cough (CC).
Objective:
This study aimed to establish validity, repeatability and responsiveness of the PGI-S scale in CC, and use the scale to define discrete categories of severity when measured with other commonly used patient-reported outcome (PRO) tools.
Methods:
Consecutive patients with CC completed the PGI-S scale, cough severity and urge-to-cough visual analogue scales (VAS), and cough-specific health status Leicester Cough Questionnaire (LCQ) at a clinic visit. Validity, repeatability and responsiveness were assessed, and threshold scores for PRO severity categories determined.
Results:
Participants (n=482; median (IQR) age 57 (46-67) years, 71% female and duration of cough 48 (24-120) months) reported median (IQR) PGI-S score 3 (3-4; moderate severity), severity VAS 57 (31-75) mm, urge VAS 62 (40-81) mm, and LCQ 11.5 (8.7-14.4). There were strong associations between PGI-S scores and severity VAS (ρ=0.81), urge VAS (ρ=0.73), and LCQ (ρ=-0.73) (all p<0.001). Repeatability of the PGI-S scale was high (n=77); intraclass correlation coefficients (95%CI) 0.85 (0.77-0.91) (p<0.001). The PGI-S scale was responsive in participants with a treatment response (p<0.001). The suggested PRO thresholds to define severe cough are ≥61 mm (cough severity VAS), ≥71 mm (urge-to-cough VAS) and ≤10 (LCQ).
Conclusion:
The PGI-S scale is a simple and valid tool that characterises cough severity, and is repeatable and responsive in CC. The proposed categorical severity thresholds for VAS and LCQ can provide intuitive meaning for patients and clinicians.
The quality of clinical trials is an essential part of the evidence base for the treatment of headache disorders. In 1991, the International Headache Society Clinical Trials Standing Committee developed and published the first edition of the Guidelines for controlled trials of drugs in migraine. Scientific and clinical developments in headache medicine led to second and third editions in 2000 and 2012, respectively. The current, fourth edition of the Guidelines retains the structure and much content from previous editions. However, it also incorporates evidence from clinical trials published after the third edition as well as feedback from meetings with regulators, pharmaceutical and device manufacturers, and patient associations. Its final form reflects the collective expertise and judgement of the Committee. These updated recommendations and commentary are intended to meet the Society's continuing objective of providing a contemporary, standardized, and evidence-based approach to the conduct and reporting of randomised controlled trials for the acute treatment of migraine attacks.
Background:
Lower urinary tract symptoms (LUTS) in aging men are often associated with benign prostatic hyperplasia (BPH). While regulatory evaluations of treatment benefit require an assessment of specific symptoms, a simpler approach to measuring patients' perceptions of severity and symptom change may be particularly useful for clinical practice. The aim of this study was to provide evidence of the validity of the 1-item Patient Global Impression of Severity (PGI-S) and Improvement (PGI-I) questionnaires for use as outcome measures in the treatment of BPH-LUTS.
Methods:
This was a secondary analysis of data from 4 randomized placebo-controlled 12-week trials evaluating tadalafil for the treatment of BPH-LUTS (N=1694). Visit 2 (V2 [beginning of a 4-week placebo lead-in period]) and endpoint assessments included International Prostate Symptom Score (IPSS), IPSS Quality of Life Index (IPSS-QoL), BPH Impact Index (BII), and peak urine flow (Qmax). PGI-S was only administered at V2 and PGI-I only at endpoint. Associations between the PGI-S or the PGI-I and the other assessments were analyzed by calculating Spearman rank correlation coefficients and performing analysis of variance (ANOVA).
Results:
Spearman correlation coefficients were 0.43, 0.43, 0.53, and -0.09, between the PGI-S and IPSS, IPSS-QoL, BII, and Qmax baseline results (all P<0.001). Similar results were seen across race, ethnicity, and baseline severity (moderate LUTS versus severe LUTS). IPSS, IPSS-QoL, BII baseline scores (P <0.001) and Qmax values (P=0.003) were significantly different among the 4 PGI-S severity levels. Spearman correlation coefficients were 0.56, 0.53, 0.47 and -0.15 between the PGI-I and change in IPSS, IPSS-QoL, BII scores, and Qmax values from baseline to endpoint (all P<0.001). Similar results were seen across race, ethnicity, and baseline severity. Change in IPSS, IPSS-QoL, BII scores, and Qmax values (P<0.001) were significantly different among the PGI-I levels (i.e., patient perception of change in urinary symptoms).
Conclusions:
This study demonstrated patients' overall perceptions of their severity and change in BPH-LUTS can be captured in a way that is simple, valid, and easily administered in a research setting or clinical practice. Clinical parameters are weakly associated with patients' perception of urinary symptoms, emphasizing the importance of a patient-reported assessment in the evaluation of BPH-LUTS treatment benefit.
Background: Insomnia is a prevalent health complaint that is often difficult to evaluate reliably. There is an important need for brief and valid assessment tools to assist practitioners in the clinical evaluation of insomnia complaints.Objective: This paper reports on the clinical validation of the Insomnia Severity Index (ISI) as a brief screening measure of insomnia and as an outcome measure in treatment research. The psychometric properties (internal consistency, concurrent validity, factor structure) of the ISI were evaluated in two samples of insomnia patients.Methods: The first study examined the internal consistency and concurrent validity of the ISI in 145 patients evaluated for insomnia at a sleep disorders clinic. Data from the ISI were compared to those of a sleep diary measure. In the second study, the concurrent validity of the ISI was evaluated in a sample of 78 older patients who participated in a randomized-controlled trial of behavioral and pharmacological therapies for insomnia. Change scores on the ISI over time were compared with those obtained from sleep diaries and polysomnography. Comparisons were also made between ISI scores obtained from patients, significant others, and clinicians.Results: The results of Study 1 showed that the ISI has adequate internal consistency and is a reliable self-report measure to evaluate perceived sleep difficulties. The results from Study 2 also indicated that the ISI is a valid and sensitive measure to detect changes in perceived sleep difficulties with treatment. In addition, there is a close convergence between scores obtained from the ISI patient's version and those from the clinician's and significant other's versions.Conclusions: The present findings indicate that the ISI is a reliable and valid instrument to quantify perceived insomnia severity. The ISI is likely to be a clinically useful tool as a screening device or as an outcome measure in insomnia treatment research.
Study objectives:
A single-item sleep quality scale (SQS) was developed as a simple and practical sleep quality assessment and psychometrically evaluated.
Methods:
SQS measurement characteristics were evaluated using the Pittsburgh Sleep Quality Index (PSQI) and morning questionnaire-insomnia (MQI) according to prespecified analysis plans in separate clinical studies of patients with insomnia and depression. Patients with insomnia (n = 70) received 4 weeks usual care with FDA-approved hypnotic agent; patients with depression (n = 651) received 8 weeks active or experimental therapy.
Results:
Concurrent criterion validity (correlation with measures of a similar construct) was demonstrated by strong (inverse) correlations between the SQS and MQI (week 1 Pearson correlation .76) and PSQI (week 8 Goodman-Kruskal correlation .92) sleep quality items in populations with insomnia and depression, respectively. In patients with depression, stronger correlations between the SQS and PSQI core sleep quality components versus other items supported convergent/divergent construct validity (similarity/dissimilarity to related/unrelated measures). Known-groups validity was evidenced by decreasing mean SQS scores across those who sleep normally, are borderline to having sleep problems, and those with problems sleeping. Test-retest reliability (intraclass correlation coefficient) was .62 during a 4-week period of sleep stability in patients with insomnia and .74 in stable patients with depression (1 week). Effect sizes (standardized response means) for change from baseline were 1.32 (week 1) and 0.67 (week 8) in populations with insomnia and depression, respectively. Mean SQS changes from baseline to week 8 convergently decreased across groups of patients with depression categorized by level of PSQI sleep quality improvement.
Conclusions:
The SQS possesses favorable measurement characteristics relative to lengthier or more frequently administered sleep questionnaires in patients with insomnia and depression.
Clinical trial registration:
Registry: ClincalTrials.gov, Title: Treatment of Patients With Major Depressive Disorder With MK0869, Identifier: NCT00034983, URL: https://clinicaltrials.gov/ct2/show/NCT00034983.
Objective:
Suvorexant is an orexin receptor antagonist that is approved in the US, Japan and Australia for the treatment of insomnia. Using outcomes from the Insomnia Severity Index (ISI) in the core registration studies, we explored suvorexant effects on sleep problems and their impact on daytime function.
Methods:
Data were pooled from two similar Phase 3, randomized, double-blind, placebo-controlled, parallel-group, three-month trials in elderly (≥65 years) and non-elderly (18-64 years old) insomnia patients. Age-adjusted (non-elderly/elderly) dose-regimes of 40/30 mg and 20/15 mg were evaluated. The ISI, a 7-item self-rated questionnaire with each item rated on 0-4 scale (higher score corresponds to increasing severity), was administered to patients as an exploratory assessment in both studies at baseline and one and three months after randomization.
Results:
The analysis included 1824 patients. Suvorexant improved change-from-baseline ISI total scores to a greater extent than placebo (Month three: 20/15 mg = -6.2, 40/30 mg = -6.7, placebo = -4.9, p-values for both active arms vs. placebo <0.001) and resulted in a greater proportion of responders than placebo using a variety of definitions (eg, ≥6-point improvement from baseline at Month three: 20/15 mg = 55.5%, 40/30 mg = 54.9%, placebo = 42.2%, p-values for both active arms vs. placebo <0.001). Additionally, the "impact of insomnia" component, which assesses the impact of insomnia on daytime function/quality-of-life, was improved to a greater extent by suvorexant than placebo.
Conclusions:
Suvorexant 20/15 mg and 40/30 mg improved sleep to a greater extent than placebo as assessed by the ISI in patients with insomnia. Improvement in sleep onset/maintenance as well as a reduction of the impact of sleep problems on daytime function contributed to the overall improvement observed in ISI total score. CLINICALTRIALS.
Gov identifier:
NCT01097616, NCT01097629.
The methodology used to construct tree structured rules is the focus of this monograph. Unlike many other statistical procedures, which moved from pencil and paper to calculators, this text's use of trees was unthinkable before computers. Both the practical and theoretical sides have been developed in the authors' study of tree methods. Classification and Regression Trees reflects these two sides, covering the use of trees as a data analysis method, and in a more mathematical framework, proving some of their fundamental properties.
Aims:
The Patient Global Index of Severity (PGI-S) and the Patient Global Index of Improvement (PGI-I) are global impression questionnaires developed in English and validated in women with stress urinary incontinence (SUI). This validation study tested the psychometric properties of German-language versions of the two questionnaires in German-speaking women with SUI.
Methods:
The German-language PGI-S and PGI-I were psychometrically tested and validated using the SF-12 questionnaire, the Kinǵs Health Questionnaire (KHQ), clinical parameters, incontinence episode frequency and pad use in 311 patients before and 3 months after receiving a TVT-O or TVT tape for SUI.
Results:
At baseline and 3 months postoperatively there was a positive correlation between PGI-S response categories and clinical parameters, IEF and pad use, and nearly all KHQ subscales. There were no correlations between response categories of PGI-S at baseline and PGI-I at 3 months and the SF-12 scales PCS-12 and MCS-12.
Conclusion:
Our results demonstrated good psychometric properties of the German-language PGI-S and PGI in German-speaking women with SUI.
Background
Suvorexant is an orexin receptor antagonist for treatment of insomnia. We report results from two pivotal Phase-3 trials.
Methods
Two randomized, double-blind, placebo-controlled, parallel-group, 3-month trials in non-elderly (18-64 years) and elderly (≥65 years) patients with insomnia. Suvorexant doses of 40/30mg (non-elderly/elderly) and 20/15mg (non-elderly/elderly) were evaluated. The primary focus was 40/30mg, with fewer patients randomized to 20/15mg. There was an optional 3-month double-blind extension in Trial-1. Each trial included a 1-week, randomized, double-blind run-out after double-blind treatment to assess withdrawal/rebound. Efficacy was assessed at Week-1, Month-1, and Month-3 by patient-reported subjective total-sleep-time (sTST) and time-to-sleep-onset (sTSO), and in a subset of patients at Night-1, Month-1, and Month-3 by polysomnographic (PSG) endpoints of Wakefulness-After-persistent-Sleep-Onset (WASO) and Latency-to-onset-of-Persistent-Sleep (LPS). 1021 patients were randomized in Trial-1 and 1019 patients in Trial-2.
Results
Suvorexant 40/30mg was superior to placebo on all subjective and PSG endpoints at Night-1/Week-1, Month-1 and Month-3 in both trials, except for LPS at Month-3 in Trial-2. Suvorexant 20/15mg was superior to placebo on sTST and WASO at Night-1/Week-1, Month-1 and Month-3 in both trials and at most individual timepoints for sTSO and LPS in each trial. Both doses of suvorexant were generally well-tolerated, with <5% of patients discontinuing due to adverse events over 3-months. The results did not suggest the emergence of marked rebound or withdrawal signs or symptoms when suvorexant was discontinued.
Conclusions
Suvorexant improved sleep onset and maintenance over 3-months of nightly treatment and was generally safe and well-tolerated.
Objective: This paper reviews the potential value in daily clinical practice of an easily applied research tool, the Clinical Global Impressions (CGI) Scale, for the nonresearcher clinician to quantify and track patient progress and treatment response over time.Method: The instrument is described and sample patient scenarios are provided with scoring rationales and a practical charting system.Conclusion: The CGI severity and improvement scales offer a readily understood, practical measurement tool that can easily be administered by a clinician in a busy clinical practice setting.
To estimate the minimally important difference (MID) for the Insomnia Severity Index (ISI) by examining the association of score differences of the ISI with health-related outcomes including health-related quality of life, productivity, and fatigue.
Data came from a randomized, placebo-controlled clinical trial evaluating the long-term efficacy of eszopiclone for primary insomnia (N = 828). Logistic regression models were used to characterize the relationship between ISI change scores (from baseline to 6 months post-treatment) and outcomes/anchors from the SF-36 Health Survey, Work Limitations Questionnaire (WLQ), and Fatigue Severity Scale (FSS). Odds ratios were derived from the regression coefficients to calculate the probability of a given outcome being associated with different ISI change scores. Convergence between anchor- and distribution-based estimates was assessed.
Higher ISI scores (indicating more severe insomnia) were significantly associated with higher probabilities of negative outcome in all models. Individuals with a 6-point score reduction in ISI scores (which corresponded to 1(1/2) standard deviations) were 48% less likely to report 'feeling worn out' (SF-36) at 6 months, 46% less likely to be 'unable to think clearly' (WLQ), and 52% less likely to report 'feeling fatigued' (FSS). Similar results were found across a broad spectrum of all selected anchors.
Based on results of the study, a 6-point reduction is recommended to represent a clinically meaningful improvement in individuals with primary insomnia. Research on generalizability of the recommended MID in this study to other patient populations and other type of treatment interventions is needed.
The purpose of this study was to assess the construct validity of two global assessment questions, the Patient Global Impression of Severity and of Improvement, in female patients with stress urinary incontinence.
This was a secondary analysis of data from two double-blind, placebo-controlled studies that evaluated duloxetine for the treatment of predominant stress urinary incontinence in the United States (n = 1133 patients). Assessment variables included incontinence episode frequency, the Incontinence Quality of Life Questionnaire results, fixed volume (400 mL) stress pad test results, and the Patient Global Impression of Improvement and of Severity question results.
Spearman correlation coefficients were 0.36, 0.20, and -0.50 among the Patient Global Impression of Severity question and incontinence episode frequency, stress pad test, and Incontinence Quality of Life Questionnaire results, respectively (all P <.0001). Mean incontinence episode frequency and median stress pad test results increased and mean Incontinence Quality of Life Questionnaire results decreased with increasing Patient Global Impression of Severity question severity levels. Similarly, significant (P <.0001) correlations were observed between the Patient Global Impression of Improvement question response categories and the three independent measures of improvement in stress urinary incontinence (0.49, 0.33, and -0.43 with incontinence episode frequency, stress pad test, and Incontinence Quality of Life Questionnaire results, respectively). As with the Patient Global Impression of Severity question, differences in mean changes for Incontinence Quality of Life Questionnaire and median percent changes for incontinence episode frequency and stress pad test among the Patient Global Impression of Improvement question response categories were highly significant (P <.0001). These relationships indicate appropriate and significant associations between the Patient Global Impression of Severity and of Improvement questions and the three independent measures of stress urinary incontinence severity and improvement, respectively.
The Patient Global Impression of Severity and of Improvement question responses were correlated significantly with incontinence episode frequency, stress pad test, and Incontinence Quality of Life Questionnaire measures, which established the construct validity of these two global assessment questions for baseline severity and treatment response, respectively.