Impact of varying outcomes and definitions of suicidality on the associations of antiepileptic drugs and suicidality: comparisons from UK Clinical Practice Research Datalink (CPRD) and Danish national registries (DNR)

PURPOSE

The purpose of this study is to quantify the impact of the different outcomes and definitions of suicidality on the association between antiepileptic drugs (AEDs) and suicidality.

METHODS

Retrospective cohort studies of selected AEDs (carbamazepine, gabapentin, lamotrigine, phenytoin, pregabalin, topiramate and valproate) using data from UK Clinical Practice Research Datalink (CPRD) alone and linked to UK Hospital Episode Statistics (HES) and UK Office of National Statistics (ONS), and from Danish national registries (DNR). Follow-up started at initiation of one of the study AEDs, divided into exposure periods, a maximum 90-day post-exposure period, and the reference period starting the day after the 90-day post-exposure period ended. Primary outcomes were completed suicide (SUI)/suicide attempt (SA) for CPRD and SUI/deliberate self-harm (DSH) for DNR. We applied adjusted Cox regression analyses and sensitivity analyses with varying outcome definitions.

RESULTS

We analyzed 84,524 AED users from CPRD-HES-ONS (1188 SUI/SA; 96 SUI) and 258,180 users from DNR (7561 SUI/DSH; 781 SUI). The adjusted hazard ratios (HRs) on SUI/SA ranged between 1.3 (95% confidence interval (CI): 0.84-2.00) for lamotrigine and 2.7 (1.24-5.81) for phenytoin in CPRD-HES-ONS, and between 0.9 (0.78-1.00) for valproate and 1.8 (1.10-3.07) for phenytoin on SUI/DSH in DNR. HRs for the primary outcomes varied consistently across exposure periods and data sources. HRs for SUI were in general lower, more stable and similar for periods of exposure and the 90-day post-exposure period.

CONCLUSION

Applying different outcomes and definitions of suicidality had an impact on the relative risks of suicidality associated with the investigated AEDs with results for SUI being most consistent and reliable.

Multiple Sclerosis and Risk of Infection-Related Hospitalization and Death in US Veterans

BACKGROUND

This study estimated the risk of infection-related hospitalizations and death in patients with and without multiple sclerosis (MS).

METHODS

We identified adults with MS in the US Department of Veterans Affairs (VA) system between 1999 and 2010. Each veteran with MS was matched, on age and sex, with up to four veterans without MS. Multivariable Cox proportional hazards regression models were performed to assess the influence of MS on the development of serious and fatal infections.

RESULTS

The cohort included 7743 veterans with MS and 30,972 veterans without MS. Mean (SD) age was 53.8 (13.3) years, and 80.8% were male. The incidence per 1000 person-years of overall serious infections was 19.2 (95% confidence interval [CI], 17.6-20.8) for those with MS and 10.3 (95% CI, 9.8-10.9) for those without MS. Fatal infection incidence rates were 1.2 (95% CI, 0.8-1.7) for patients with MS and 0.5 (95% CI, 0.3-0.6) for patients without MS. Regression models showed that veterans with MS were at greater risk for overall serious (hazard ratio [HR] = 1.52, P < .01) and fatal (HR = 1.85, P = .03) infections and serious respiratory (HR = 1.31, P = .01), urinary tract (HR = 4.44, P < .01), and sepsis-related infections (HR = 2.56, P < .01).

CONCLUSIONS

This study provides evidence that VA patients with MS are more likely than those without MS to be hospitalized and die of infection.

Seizures in patients with Alzheimer's disease or vascular dementia: a population-based nested case-control analysis

PURPOSE

Patients with Alzheimer's disease (AD) have an increased risk of developing seizures or epilepsy. Little is known about the role of risk factors and about the risk of developing seizures/epilepsy in patients with vascular dementia (VD). The aim of this study was to assess incidence rates (IRs) of seizures/epilepsy in patients with AD, VD, or without dementia, and to identify potential risk factors of seizures or epilepsy.

METHODS

We conducted a follow-up study with a nested case-control analysis using the United Kingdom-based General Practice Research Database (GPRD). We identified patients aged ≥65 years with an incident diagnosis of AD or VD between 1998 and 2008 and a matched comparison group of dementia-free patients. Conditional logistic regression was used to estimate the odds ratio (OR) with a 95% confidence interval (CI) of developing seizures/epilepsy in patients with AD or VD, stratified by age at onset and duration of dementia as well as by use of antidementia drugs.

KEY FINDINGS

Among 7,086 cases with AD, 4,438 with VD, and 11,524 matched dementia-free patients, we identified 180 cases with an incident diagnosis of seizures/epilepsy. The IRs of epilepsy/seizures for patients with AD or VD were 5.6/1,000 person-years (py) (95% CI 4.6-6.9) and 7.5/1,000 py (95% CI 5.7-9.7), respectively, and 0.8/1,000 py (95% CI 0.6-1.1) in the dementia-free group. In the nested case-control analysis, patients with longer standing (≥3 years) AD had a slightly higher risk of developing seizures or epilepsy than those with a shorter disease duration, whereas in patients with VD the contrary was observed.

SIGNIFICANCE

Seizures or epilepsy were substantially more common in patients with AD and VD than in dementia-free patients. The role of disease duration as a risk factor for seizures/epilepsy seems to differ between AD and VD.

[Delirium, depression, dementia: solving the 3D's]

As there is no consensus in the specialized literature, it is often difficult to recognize the ties existing between dementia, delirium and depression. Depression preceding dementia is well-documented. Depressive symptoms during the process of dementia are less well-known. So are the close relationships between dementia and delirium as well as between delirium and depression. The commonality of symptoms between the three often causes diagnostic dilemmas. Unfortunately, elderly patients can often present two, or even three, of the "3 D's" simultaneously. Untangling the 3 D's has been the subject of several articles. We propose a synthesis as well as our thoughts on the subject from a clinical psychogeriatric standpoint.

[A study of endogenous evoked potentials (P300 and CNV) in retired patients]

Endogenous evoked potentials of two types (CNV and P300 complexes) as well as their respective reaction times were recorded in 29 elderly, active subjects (15 men and 14 women) between 60 and 84 years of age. Our subjects also passed anxiety, depression and cognitive scales. The different results were then analyzed in relation with each other and in relation with age and sex. No age-related differences were found in the principal elements measured in the P300 complex, but several elements of the CNV complex were clearly shown to be age-sensitive. Sex-related differences were found in the N2 and P3a potentials. CNV morphology (Tecce type A) and cognitive scores were found to be related to Spielberger's anxiety-trait sub-scale. Several results also highlighted the heterogeneity of this age group. The need for complementary studies in this age group is then discussed with the hope that neurophysiology can become a useful tool in psychogeriatrics.