Reliability, validity and responsiveness of a revised scoring system for the Liverpool Seizure Severity Scale

This report examines the reliability, validity and responsiveness of a revised scoring system for the Liverpool Seizure Severity Scale (LSSS). The revised scoring system was validated using archival data from an observational study and a randomized controlled study. Factor analyses confirmed that a single dimension captured how patients evaluate the severity of their most severe seizures occurring during a recall period. The revised scoring system repositions the severity score to range from 0 (no seizures) to 100 (most severe possible). Scores based on the new system were reliable, had construct validity (known-groups validity), and were responsive to changes in the patients' epilepsy as noted by their physicians. Results suggest that future epilepsy studies assessing seizure severity should incorporate the revised LSSS scoring system and a modified version of the questionnaire that simplifies self-assessment and analyses. The modified version of the LSSS and its scoring system are appended to this report.     

The Chalfont Seizure Severity Scale.

Seizure severity has been largely neglected in studies of patients with epilepsy and the evaluations of treatment. A seizure severity scale, that measures the components of seizures that cause patients the most disturbance, is presented with an assessment of the scale's validity and reliability.     

Seizure Severity in Children with Epilepsy: A Parent-Completed Scale Compared with Clinical Data

Summary: Purpose: We wished to compare a parent-completed scale quantifying seizure severity (SS) in children with various seizure types with the clinicians' impression of SS and other clinical data. Methods: The parents of 117 children with recurrent seizures completed a 13-item, subjective scale (The Hague Seizure Severity Scale, HASS). Eight treating neurologists quantified SS on a 10-point Visual Analog Scale (VAS) and supplied other clinical data. Results: Both the HASS and the VAS assessments of SS showed considerable variation within one seizure type. Significant differences were noted between groups with (a) absences and simple partial seizures (SPS), (b) complex partial seizures (CPS), and (c) generalized tonic-clonic seizures (GTCS). The correlation coefficient between the neurologists' and the parents' scores was 0.45 but did not exceed 0.26 after stratification for seizure type. The parents' score was not substantially influenced by various other clinical variables. The neurologists' score was correlated with resistance to treatment and presence of mental retardation. Conclusions: The SS ratings of the parents and the neurologists were not substantially correlated. The consideration that parents, as eyewitnesses to the seizures, are probably better judges of SS than clinicians may favor the use of a parent-completed scale to quantify SS. The HASS is a valid and reliable measure of parent-perceived SS that can be useful as an outcome measure in childhood epilepsy.     

The validation of a caregiver assessment of dementia: the Dementia Severity Scale

OBJECTIVE: The objective of this study was to refine and validate the Dementia Severity Scale (DSS), a newly developed assessment of dementia severity from a caregiver's perspective. The Dementia Severity Scale is designed to measure deficits in activities of daily living (ADL), behavioral disturbances, and the caregiver's perception of the patient's current cognitive abilities. METHODS: Community dwelling caregiver/patient dyads were recruited from 12 clinical sites. Patients had a primary dementia diagnosis for at least one year. In this cross-sectional study, caregivers were administered the Dementia Severity Scale, the Quality of Life-Alzheimer's Disease (QOL-AD), the Progressive Deterioration Scale (PDS), and the Neuropsychiatric Inventory (NPI). Patients were administered the Mini-Mental State Examination (MMSE) and the QOL-AD. To evaluate test-retest reliability, 25% of caregivers were randomized to a second visit. RESULTS: One hundred eighty-three caregiver/patient dyads were recruited. Mean caregiver age was 67.5; mean patient age was 78.8; 93% of patients had probable Alzheimer disease. Eighty-eight (48.1%) patients were male. Exploratory factor analysis established 6 subscales (Activities of Daily Living [ADL], Instrumental ADL [IADL], Communication, Agitation, Memory, and Disorganized Thinking). Cronbach's alphas ranged from 0.82 to 0.90 for the 6 subscales. Test-retest reliability was good with intraclass correlation coefficients ranging from 0.79 to 0.89. DSS subscales were moderately-to-highly correlated with the QOL-AD, NPI, MMSE, and PDS. Subscales significantly discriminated among severity levels of dementia, identified by both physician ratings and MMSE scores. CONCLUSION: The Dementia Severity Scale demonstrated excellent psychometric properties and appears to be useful both in clinical practice and research endeavors. Further research is needed to establish the longitudinal sensitivity of the Dementia Severity Scale to the progression of dementia.     

Determining minimally important change thresholds for the Seizure Severity Questionnaire (SSQ)

The Seizure Severity Questionnaire (SSQ) was developed to evaluate changes in seizure severity and bothersomeness. Determination of a threshold value reflecting meaningful patient benefit on the SSQ would improve clinical interpretation of scale results. The objective of this analysis was to define a minimally important change (MIC) threshold for the SSQ, using data from patients with treatment-resistant partial-onset seizures from two clinical trials (N = 776). Minimally important change thresholds were calculated using standard anchor-based methods, with the Patient Global Impression of Change (PGIC) score as the anchor with the categories of ‘much improved,’ ‘minimally improved,’ ‘much worsened,’ and ‘minimally worsened’ combined. The calculated MIC thresholds (range: 0.34 to 0.50) suggest that a 0.48-point change in the SSQ total score reflects a clinically meaningful change in seizure severity from the patients' perspective.     

Cross-cultural evaluation of the Panic Disorder Severity Scale in Japan

The Panic Disorder Severity Scale (PDSS) [Shear et al., 1997] is rapidly gaining world-wide acceptance as a standard global severity measure of panic disorder, however, its cross-cultural validity and reliability have not been reported yet. We developed the Japanese version of the PDSS and examined its factor structure, internal consistency and inter-rater reliability and concurrent validity among Japanese patients with panic disorder with or without agoraphobia. We also established rules of thumb for interpreting PDSS total scores, taking the Clinical Global Impression severity scale as the anchoring criterion. The identical one-factor structure of the PDSS was confirmed among the Japanese patients as among the United States patients. Both internal and inter-rater reliability was excellent (Cronbach's alpha was 0.86, and ANOVA ICCs were all above 0.90). Concurrent validity of the PDSS items with self-report questionnaires tapping similar or overlapping domains was satisfactory (Pearson correlation coefficients were mostly above 0.5). Using the anchor-based approach, the following interpretative guides are suggested: among those with established panic disorder diagnosis, PDSS total scores up to 10 correspond with "mild," those between 11 and 15 with "moderate," and those at or above 16 correspond with "severe" panic disorder. The present findings support the cross-cultural generalizability of panic disorder symptomatology and of the PDSS, in particular.     

Reliability and validity of the Chinese version of Narcolepsy Severity Scale in adult patients with narcolepsy type 1

ObjectiveTo evaluate reliability and validity of the Chinese version of Narcolepsy Severity Scale (NSS) in adult patients with narcolepsy type 1 (NT1).MethodsOne hundred and fifty-one adult patients (≥18 years) with NT1 were recruited. All filled out the 15-item Chinese version of NSS. Item analysis included critical ratio and correlation analysis. The validity of NSS was assessed by exploratory factor analysis, discriminant validity and convergent validity. Reliability of NSS was assessed by Cronbach's α coefficient, spilt-half reliability and test-retest reliability.ResultsCritical value of all 15 items ranged from 3.01 to 13.36. Each item was significantly correlated with the total score by a correlation coefficient (r) ranging from 0.219 to 0.700. Three common domains were extracted and 15 items explained 54.86% of the total variance. There was a shift in domains compared to the English version likely due to cultural differences. Cronbach's α coefficient for the total scale of 15 items was 0.821 and for three factors was 0.726, 0.748 and 0.760 respectively. The NSS had good correlation with Epworth sleepiness scale scores, Insomnia severity index scores and moderate correlation with mean the sleep latency of polysomnographic recording, and European Quality of Life-5 Dimensions Questionnaire. The Chinese version of NSS showed good spilt-half reliability and test-retest reliability.ConclusionThe Chinese version of NSS shows satisfactory psychometric properties with good validity and reliability. It is applicable to evaluate the severity and consequences of symptoms in Chinese adult patients with NT1.     

Assessment of Seizure Severity with Adjunctive Lamotrigine Therapy: Results from a U.S. Observational Study

THE ADJUNCTIVE LAMICTAL (LAMOTRIGINE) IN EPILEPSY: Response to Treatment (ALERT) study was an observational study designed to assess the safety of lamotrigine in patients with refractory partial seizures when used in a general practice setting. We measured the impact of adjunctive lamotrigine therapy for 16 weeks on the severity of seizures using the Liverpool Seizure Severity Scale (LSSS). This questionnaire was scored using a revised scoring procedure that assesses the impact of treatment on the patients "most severe seizure." Data from the LSSS were also compared with physician-rated changes of seizure severity. Patients who completed 16 weeks of lamotrigine treatment showed a significant reduction in LSSS scores when compared with patients who discontinued lamotrigine (change scores: patient's taking lamotrigine at Week 16, 9.2 +/- 23.4; patients who discontinued lamotrigine by Week 16, 0.8 +/- 23.4, P < 0.05). These findings were supported by significant reductions in physician ratings of seizure severity in patients who completed 16 weeks of lamotrigine therapy. Seizure severity is an important outcome in the study of antiepileptic medication. Data from this observational study suggest that lamotrigine is effective in reducing seizure severity when used as an adjunctive therapy in patients with refractory partial seizures.     

Validation of the Augmentation Severity Rating Scale (ASRS): a multicentric, prospective study with levodopa on restless legs syndrome

BACKGROUND: Augmentation is the main complication during long-term dopaminergic treatment of restless legs syndrome (RLS) and reflects an overall increase in RLS severity. Its severity varies considerably from a minor problem to a devastating exacerbation of disease. Despite its clinical relevance, systematic evaluations have rarely been undertaken and there has been no development of methods to assess the severity of augmentation. To fill this gap, the European RLS Study Group (EURLSSG) has developed the Augmentation Severity Rating Scale (ASRS), using three items that assess the degree of change in three specific dimensions of augmentation. The changes in each dimension are summed to give an ASRS total score. METHODS: The ASRS was developed to cover the basic dimensions defining RLS augmentation. The items were developed by an interactive process involving professional and patient input. The ASRS that was evaluated included four major items and two alternative forms of one item. The validation was conducted using 63 (85%) mostly untreated RLS patients from six centers, who were treated for six months with levodopa (L-Dopa) (up to 500 mg/day, as clinically needed). Two consecutive assessments before and at baseline measured test-retest reliability. Consecutive ASRS ratings by two independent raters on a subsample of patients evaluated inter-rater reliability. Comparison with clinical severity ratings of two independent experts provided external validation of the ASRS. Comparison of patients with and without augmentation with regard to the items and the total score of the ASRS added discriminant validity. RESULTS: Sixty patients (63% females, mean age: 53 years, baseline International RLS Severity Rating (IRLS) score 24.7+/-5.2) were treated with a median daily dose of 300 mg L-Dopa (range: 50-500 mg). Thirty-six patients (60%) experienced augmentation. Item analyses indicated that one item could be removed as it did not contribute significantly to the test score and only one form of the duplicated item needed to be used. The final ASRS then included three items. Test-retest reliability for the total score was rho=0.72, and inter-rater reliability was rcc=0.94. Cronbach's alpha was 0.62. Validity as assessed by the correlation between the worst ASRS total score during the trial and the expert rating was rho=0.72. ASRS total score differed between patients without versus with augmentation (mean: 7.4 (standard deviation (SD)=4.0) vs. 2.0 (2.7) (P<0.0001). CONCLUSIONS: The ASRS is a reliable and valid scale to measure the severity of augmentation. Due to the need to systematically quantify augmentation for both long-term efficacy and tolerability, the ASRS may become a useful tool to monitor augmentation in future clinical trials.     

The development of a seizure severity scale as an outcome measure in epilepsy

In controlled trials of antiepileptic drugs (AEDs) seizure frequency is often the only variable considered. With little prospect of improving assessment of AEDs, using seizure counts as the only end-point, there is a need for the development of new outcome measures. Clinical experience indicates that seizure severity is equally important to the patient and, by preventing seizure spread, AEDs can influence seizure severity without necessarily reducing seizure frequency. A scale capable of measuring seizure severity and change of severity attributable to treatment could be a useful additional outcome measure. Such a scale should exhibit the basic properties of validity and reliability. An easily administrable 16-point scale, containing 2 subscales--perception of control and ictal/post-ictal effects--has been developed. This scale has been tested on a patient population (n = 159) representative of that seen in trials of novel AEDs. Using standardised statistical methods, the scale has been shown to be both reliable and valid.