Trace metals and polycyclic aromatic hydrocarbons in the Eastern Mediterranean sediments: Concentration ranges as a tool for quality control of large data collections.

Assessing the status of marine pollution at regional and sub-regional scales requires the use of comparable and harmonized data provided by multiple institutions, located in several countries. Standardized data management and quality control are crucial for supporting a coherent evaluation of marine pollution. Taking the Eastern Mediterranean Sea as a case study, we propose an approach to improve the quality control procedures used for sediment pollution data, thus supporting a harmonized environmental assessment. The regional ranges of contaminant concentrations in sediments were identified based on an in-depth literature review, and the lowest measured concentrations were evaluated to determine the "background concentrations" of chemical substances not yet targeted in the Mediterranean Sea. In addition, to verify the suitability of the approach for validating large data collections provided by multiple sources, the determined ranges were used to validate a regional dataset available through EMODnet data infrastructure.

Seizure identification by clinical description in temporal lobe epilepsy: how accurate are we?

OBJECTIVE: To determine the accuracy of the clinical history performed by epileptologists in the identification of seizures in patients with suspected temporal lobe epilepsy. METHODS: The clinical and EEG telemetry (EEGT) monitoring data of 88 patients with suspected refractory temporal lobe seizures referred for evaluation of epilepsy surgery were prospectively evaluated. All clinical events obtained by history in these patients were adjudicated as being a seizure or not by two blinded (without access to EEG data) independent epileptologists. Each clinical event was then matched with the corresponding clinical event recorded with EEG telemetry in the epilepsy monitoring unit (gold standard). Sensitivity, specificity, overall accuracy, predictive value, and interrater agreement for the clinical assessment were obtained. RESULTS: Of 357 clinically different events, 175 (49%) were reproduced in the epilepsy monitoring unit. Only 10 events were misidentified by history as being a seizure or not, resulting in an overall clinical accuracy of 94%. Epileptologists' sensitivity for seizure identification was 96% (95% CI 92, 98%) but specificity was only 50% (95% CI 22, 79%). Accuracy for complex partial seizures and generalized seizures was higher than for simple partial seizures (SPS). Misidentification occurred only with SPS and nonepileptic events. Agreement beyond chance among epileptologists was good. CONCLUSION: In this selected group of patients with temporal lobe epilepsy, seizure identification by clinical history is highly accurate. Epileptologists rarely miss seizures (high sensitivity) but more often overcall nonepileptic events as seizures (low specificity).

Clinically important change in quality of life in epilepsy.

BACKGROUND: Health related quality of life (HRQOL) is increasingly recognised as an important outcome in epilepsy. However, interpretation of HRQOL data is difficult because there is no agreement on what constitutes a clinically important change in the scores of the various instruments. OBJECTIVES: To determine the minimum clinically important change, and small, medium, and large changes, in broadly used epilepsy specific and generic HRQOL instruments. METHODS: Patients with difficult to control focal epilepsy (n = 136) completed the QOLIE-89, QOLIE-31, SF-36, and HUI-III questionnaires twice, six months apart. Patient centred estimates of minimum important change, and of small, medium, and large change, were assessed on self administered 15 point global rating scales. Using regression analysis, the change in each HRQOL instrument that corresponded to the various categories of change determined by patients was obtained. The results were validated in a subgroup of patients tested at baseline and at nine months. RESULTS: The minimum important change was 10.1 for QOLIE-89, 11.8 for QOLIE-31, 4.6 for SF-36 MCS, 3.0 for SF-36 physical composite score, and 0.15 for HUI-III. All instruments differentiated between no change and minimum important change with precision, and QOLIE-89 and QOLIE-31 also distinguished accurately between minimum important change and medium or large change. Baseline HRQOL scores and the type of treatment (surgical or medical) had no impact on any of the estimates, and the results were replicated in the validation sample. CONCLUSIONS: These estimates of minimum important change, and small, medium, and large changes, in four HRQOL instruments in patients with epilepsy are robust and can distinguish accurately among different levels of change. The estimates allow for categorisation of patients into various levels of change in HRQOL, and will be of use in assessing the effect of interventions in individual patients.

Changes in quality of life in epilepsy: how large must they be to be real?

PURPOSE: The study goal was to assess the magnitude of change in generic and epilepsy-specific health-related quality-of-life (HRQOL) instruments needed to exclude chance or error at various levels of certainty in patients with medically refractory epilepsy. METHODS: Forty patients with temporal lobe epilepsy and clearly defined criteria of clinical stability received HRQOL measurements twice, 3 months apart, using the Quality of Life in Epilepsy Inventory-89 and -31 (QOLIE-89 and QOLIE-31), Liverpool Impact of Epilepsy, adverse drug events, seizure severity scales, and the Generic Health Utilities Index (HUI-III). Standard error of measurement and test-retest reliability were obtained for all scales and for QOLIE-89 subscales. Using the Reliable Change Index described by Jacobson and Truax, we assessed the magnitude of change required by HRQOL instruments to be 90 and 95% certain that real change has occurred, as opposed to change due to chance or measurement error. RESULTS: Clinical features, point estimates and distribution of HRQOL measures, and test-retest reliability (all > 0.70) were similar to those previously reported. Score changes of +/-13 points in QOLIE-89, +/-15 in QOLIE-31, +/-6.3 in Liverpool seizure severity-ictal, +/-11 in Liverpool adverse drug events, +/-0.25 in HUI-III, and +/-9.5 in impact of epilepsy exclude chance or measurement error with 90% certainty. These correspond, respectively, to 13, 15, 17, 18, 25, and 32% of the potential range of change of each instrument. CONCLUSIONS: Threshold values for real change varied considerably among HRQOL tools but were relatively small for QOLIE-89, QOLIE-31, Liverpool Seizure Severity, and adverse drug events. In some instruments, even relatively large changes cannot rule out chance or measurement error. The relation between the Reliable Change Index and other measures of change and its distinction from measures of minimum clinically important change are discussed.