Predictors of health-related quality of life and costs in adults with epilepsy: a systematic review

Diagnostic evaluation in patients with intractable epilepsy and normal findings on MRI: a decision analysis and cost-effectiveness study

BACKGROUND AND PURPOSE

Patients with focal intractable epilepsy and normal MR imaging findings frequently undergo further diagnostic tests to localize the epileptogenic zone. The aim of this study was to determine the cost-effective diagnostic strategy that will identify the epileptogenic zone in patients with suspected focal intractable epilepsy and normal MR imaging findings by using decision analysis.

MATERIALS AND METHODS

A Markov decision model was constructed by using sensitivities and specificities of test strategies, seizure outcomes following surgical and medical treatment, cost, utilities, probabilities, and standardized mortality ratios. We compared 6 diagnostic test strategies: PET, ictal SPECT, and MEG individually; and combinations of PET+SPECT, PET+MEG, and SPECT+MEG. The outcomes measured were health care costs, QALY, and ICER. One-way and probabilistic sensitivity analyses were conducted to adjust for uncertainties in model parameters.

RESULTS

The preferred strategies were PET+MEG and SPECT. The health care cost of the baseline strategy (PET+MEG) was $95,612 with 16.30 QALY gained. SPECT cost $97,479 with 16.45 QALY gained and an ICER of $12,934/QALY gained compared with those in PET+MEG. One-way sensitivity analyses showed that the decisions of the model were sensitive to variations in sensitivity and specificity of the test strategies. Probabilistic sensitivity analysis showed that when the willingness to pay was <$10,000, PET+MEG was the favored strategy, but the favored strategy changed to SPECT when the willingness to pay was >$10,000.

CONCLUSIONS

PET+MEG and SPECT were the preferred strategies in the base case. The choice of test was dependent on the sensitivity and specificity of test strategies and willingness to pay. Further study with a larger sample size is needed to obtain better estimates of sensitivity and specificity of diagnostic tests.

Predictors of health-related and global quality of life among young adults with difficult-to-treat epilepsy and mild intellectual disability

OBJECTIVE

This study evaluated predictors of health-related quality of life (HRQOL) and global quality of life (QOL) among young adults with difficult-to-treat epilepsy and mild intellectual disability.

METHODS

One hundred and forty-two persons with epilepsy and cognitive problems were routinely screened on HRQOL, global QOL, and psychological distress four weeks after admission to a time-limited residential rehabilitation unit. The PESOS scales (PE = PErformance, SO = SOciodemographic aspects, S = Subjective evaluation/estimation) on epilepsy-specific problems were administered as measures of HRQOL; a questionnaire on life satisfaction and an item on overall QOL were used as measures of global QOL. Psychological distress was captured with the Symptom Checklist 90-R. Further data were gained from medical files. Quality-of- life predictors were identified using univariate methods and stepwise regression analyses.

RESULTS

Psychological distress was the only predictor of all HRQOL and global QOL parameters. Seizure frequency was a predictor of most HRQOL variables. Other epilepsy variables affected only some HRQOL variables but were not associated with global QOL. Health-related quality of life did not seem to be strongly impaired. Only low correlations were found between HRQOL and global QOL.

CONCLUSION

The notion of psychological distress as the most influential predictor of all QOL measures is in line with most findings on QOL in epilepsy. Former observations of weak associations between HRQOL and global QOL among patients with epilepsy and mild intellectual disability are supported. Thus, interventions to reduce psychological distress, besides epilepsy treatment, seem to be of great importance to improve QOL.

Positive Coping, Self-Efficacy, and Self-Esteem as Mediators Between Seizure Severity and Life Satisfaction in Epilepsy

This study examined the impact of positive psychological traits (positive coping, self-efficacy, and self-esteem) on the relationship between seizure severity and life satisfaction among individuals with epilepsy. Hierarchical regression analysis and correlation techniques were used to test a hypothesized tri-mediation model of life satisfaction for individuals with epilepsy. Results indicated that seizure severity and positive human traits, including positive coping, self-efficacy, and self-esteem, were indeed associated with overall life satisfaction. Self-efficacy and self-esteem (but not positive coping) fully mediated the relationship between seizure severity and life satisfaction, lending support for a dual-mediation model. These findings suggest there may be considerable value for rehabilitation psychologists and counselors to develop specialized intervention programs that focus on capitalizing these positive human traits to promote life satisfaction and well-being for clients with epilepsy.

Predictors of quality of life in patients with refractory mesial temporal lobe epilepsy

PURPOSE

The identification of variables associated with health-related quality of life (HRQoL) in patients with mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS) would improve surgical decision-making and post-operatory follow-up in this group of patients.

METHODS

We analyzed the independent association between the Quality of Life in Epilepsy Inventory-31 (QOLIE-31) of 81 consecutive patients with refractory MTLE-HS. The clinical, demographic, radiological and electrophysiological variables were analyzed by multiple linear regression analysis.

KEY FINDINGS

Approximately 36% (adjusted R(2)=0.36; R coefficient=0.66) of the QOLIE-31 overall score variance was explained by the history of initial precipitant injury, family history of epilepsy, disease duration, age of epilepsy onset, seizure frequency and presence of psychiatric axis-II diagnosis. The variance of QOLIE-31 sub-scales was: seizure worry=7%; overall QOL=11%; emotional well-being=32%; energy/fatigue=38%; cognitive function=13%; medication effects=7%; social function=13% (R coefficient between 0.30 and 0.65).

SIGNIFICANCE

The pre-surgical variables studied had relatively low prediction capacity for the overall QOLIE-31 score and its sub-scales in this set of Brazilian patients with refractory MTLE-HS.

AAN Epilepsy Quality Measures in clinical practice: a survey of neurologists

Epilepsy Quality Measures (EQM) were developed by the American Academy of Neurology (AAN) to convey standardization and eliminate gaps and variations in the delivery of epilepsy care (Fountain et al., 2011 [1]). The aim of this study was to identify adherence to these measures and other emerging practice standards in epilepsy care. A 15-item survey was mailed to neurologists in Michigan, USA, inquiring about their practice patterns in relation to EQM. One hundred thirteen of the 792 surveyed Michigan Neurologists responded (14%). The majority (83% to 94%) addressed seizure type and frequency, reviewed EEG and MRI, and provided pregnancy counseling to women of childbearing potential. Our survey identified gaps in practice patterns such as counseling about antiepileptic drug (AED) side effects and knowledge about referral for surgical therapy of intractable epilepsy. Statistical significance in the responses on the AAN EQM was noted in relation to number of years in practice, number of epilepsy patients seen, and additional fellowship training in epilepsy. Practice patterns assessment in relation to other comorbidities revealed that although bone health and sudden unexplained death in epilepsy are addressed mainly in patients at risk, depression is infrequently discussed. The findings in this study indicate that additional educational efforts are needed to increase awareness and to improve quality of epilepsy care at various points of health care delivery.

Quality of life in young adults who underwent resective surgery for epilepsy in childhood

PURPOSE

This study investigated quality of life (QOL) in young adults who had undergone epilepsy surgery before the age of 16 years. The contribution to QOL of seizure status in the prior year, sex, number of antiepileptic drugs, and mood were evaluated.

METHODS

Sixty-nine young adults who had undergone surgery were subdivided into those who were seizure-free in the past year (n = 38) and those who had seizures (n = 31) in that time. A nonsurgical comparison group of young adults (n = 29) with childhood-onset medically intractable epilepsy was also studied. All groups completed measures of QOL and mood.

KEY FINDINGS

After accounting for mood, sex, and number of antiepileptic drugs, the seizure-free group reported better cognitive and physical function and overall QOL, experienced less seizure worry, and had better self-perception. Mood was the most consistently predictive covariate, and was independently predictive of many aspects of QOL.

SIGNIFICANCE

Seizure freedom associated with surgery in childhood is associated with improved QOL in certain domains. Findings highlight the importance of mood in determining self-perception of QOL.

Determinants of health-related quality of life in pharmacoresistant epilepsy: results from a large multicenter study of consecutively enrolled patients using validated quantitative assessments

PURPOSE

To evaluate the relative contribution of demographic and epilepsy-related variables, depressive symptoms, and adverse effects (AEs) of antiepileptic drugs (AEDs) to health-related quality of life (HRQOL) in adults with pharmacoresistant epilepsy.

METHODS

Individuals with epilepsy whose seizures failed to respond to at least one AED were enrolled consecutively at 11 tertiary referral centers. HRQOL was assessed by the Quality of Life in Epilepsy Inventory-31 (QOLIE-31), AEs by the Adverse Event Profile (AEP), and depressive symptoms by the Beck Depression Inventory-II (BDI-II). Multivariate linear regression models were used to identify variables associated with QOLIE-31 total score and subscale scores.

KEY FINDINGS

Of 933 enrolled individuals aged 16 years or older, 809 (87%) were able to complete the self-assessment instruments and were included in the analysis. Overall, 61% of the variance in QOLIE-31 scores was explained by the final model. The strongest predictors of HRQOL were AEP total scores (β = -0.451, p < 0.001) and BDI-II scores (β = -0.398, p < 0.001). These factors were also the strongest predictors of scores in each of the seven QOLIE-31 subscales. Other predictors of HRQOL were age (β = -0.060, p = 0.008), lack of a driving license (β = -0.053, p = 0.018), pharmacoresistance grade, with higher HRQOL in individuals who had failed only one AED (β = 0.066, p = 0.004), and location of the enrolling center. Epilepsy-related variables (seizure frequency, occurrence of tonic-clonic seizures, age of epilepsy onset, disease duration) and number of AEDs had no significant predictive value on HRQOL. The AEP total score was the strongest negative predictor of HRQOL in the subgroup of 362 patients without depressive symptoms (BDI-II score <10), but even in this subgroup the BDI-II score was retained as a significant predictor.

SIGNIFICANCE

In individuals with pharmacoresistant epilepsy, AEs of medication and depressive symptoms are far more important determinants of HRQOL than seizures themselves. When seizure freedom cannot be achieved, addressing depressive comorbidity and reducing the burden of AED toxicity is likely to be far more beneficial than interventions aimed at reducing the frequency of seizures.