Assessing the extent and determinants of socioeconomic inequalities in epilepsy in the UK: a systematic review and meta-analysis of evidence.

BACKGROUND: Socioeconomic inequalities in epilepsy incidence and its adverse outcomes are documented internationally, yet the extent of inequalities and factors influencing the association can differ between countries. A UK public health response to epilepsy, which prevents epilepsy without widening inequalities, is required. However, the data on UK epilepsy inequalities have not been synthesised in a review and the underlying determinants are unknown. METHODS: In this systematic review and meta-analysis, we searched six bibliographic databases (MEDLINE, Embase, PsycINFO, CINAHL, Web of Science, and Scopus) and grey literature published between Jan 1, 1980, and Feb 21, 2024, to identify UK studies reporting epilepsy incidence or epilepsy-related adverse outcomes by socioeconomic factors (individual level or area level). We included longitudinal cohort studies, studies using routinely collected health-care data, cross-sectional studies, and matched cohort studies and excluded conference abstracts and studies not reporting empirical results in the review and meta-analysis. Multiple reviewers (KJB, EC, SER, WOP, and RHT) independently screened studies, KJB extracted data from included studies and a second reviewer (SM or EC) checked data extraction. We used Critical Appraisal Skills Programme checklists to assess quality. We used random-effects meta-analysis to pool incident rate ratios (IRRs) and synthesised results on adverse outcomes narratively. This study was registered on PROPSPERO (CRD42023394143). FINDINGS: We identified 2471 unique studies from database searches. We included 26 studies, ten of which reported epilepsy incidence and 16 reported epilepsy-related adverse outcomes according to socioeconomic factors. Misclassification, participation, and interpretive biases were identified as study quality limitations. Meta-analyses showed an association between socioeconomic deprivation and epilepsy incidence, with greater risks of epilepsy incidence in groups of high-deprivation (IRR 1·34 [95% CI 1·16-1·56]; I2=85%) and medium-deprivation (IRR 1·23 [95% CI 1·08-1·39]; I2=63%) compared with low-deprivation groups. This association persisted in the studies that only included children (high vs low: IRR 1·36 [95% CI 1·19-1·57]; I2=0%). Only two studies examined factors influencing epilepsy incidence. There is limited evidence regarding UK inequalities in adverse outcomes. INTERPRETATION: Socioeconomic inequalities in epilepsy incidence are evident in the UK. To develop an evidence-based public health response to epilepsy, further research is needed to understand the populations affected, factors determining the association, and the extent of inequalities in adverse outcomes. FUNDING: Epilepsy Research Institute UK.

Influence of neighborhood-level socioeconomic deprivation and individual socioeconomic position on risk of developing type 2 diabetes in older men: a longitudinal analysis in the British Regional Heart Study cohort.

INTRODUCTION: Evidence from longitudinal studies on the influence of neighborhood socioeconomic deprivation in older age on the development of type 2 diabetes mellitus (T2DM) is limited. This study investigates the prospective associations of neighborhood-level deprivation and individual socioeconomic position (SEP) with T2DM incidence in older age. RESEARCH DESIGN AND METHODS: The British Regional Heart Study studied 4252 men aged 60-79 years in 1998-2000. Neighborhood-level deprivation was based on the Index of Multiple Deprivation quintiles for participants' 1998-2000 residential postcode. Individual SEP was defined as social class based on longest-held occupation. A cumulative score of individual socioeconomic factors was derived. Incident T2DM cases were ascertained from primary care records; prevalent cases were excluded. Cox proportional hazard models were used to examine the associations. RESULTS: Among 3706 men, 368 incident cases of T2DM were observed over 18 years. The age-adjusted T2DM risk increased from the least deprived quintile to the most deprived: HR per quintile increase 1.14 (95% CI 1.06 to 1.23) (p=0.0005). The age-adjusted T2DM HR in social class V (lowest) versus social class I (highest) was 2.45 (95% CI 1.36 to 4.42) (p=0.001). Both associations attenuated but remained significant on adjustment for other deprivation measures, becoming non-significant on adjustment for body mass index and T2DM family history. T2DM risk increased with cumulative individual adverse socioeconomic factors: HR per point increase 1.14 (95% CI 1.05 to 1.24). CONCLUSIONS: Inequalities in T2DM risk persist in later life, both in relation to neighborhood-level and individual-level socioeconomic factors. Underlying modifiable risk factors continue to need to be addressed in deprived older age populations to reduce disease burden.