Table 2 Study characteristics
From: The burden of illness in Lennox–Gastaut syndrome: a systematic literature review
Study, year (Publication type) Country Database | Study type and source of data | Time period | Population: Number | Definition of LGS | Characteristics: Age, mean (SD; median [range]), years; Male, % | Outcomes |
|---|---|---|---|---|---|---|
Burden-of-illness/costs and resource | ||||||
Piña-Garza [46] (Full) USA MEDLINE and Embase | Retrospective insurance claims analysis: Medicaid multi-state database of six states | Observation period: mean (SD): 11.1 (4.5) years (1997/98–2012/13) | Probable LGS: N=14,712 | ≥2 medical claims ≥30 days apart for specified epilepsy or unspecified epilepsy (ICD-9-CM codes) Machine-learning technique based on a number of clinical variables (including use of rufinamide during the testing & training period) | 16.3 (15.7); 52.5% male | Epidemiology Resource Direct costs |
Strzelczyk 2021 [47](Full) Germany MEDLINE, Embase and APA PsycInfo | Retrospective insurance claims analysis: Vilua Healthcare research database, entries for >4 million people i.e ~5% of the German population | 10 years (2007–2016) | Broad LGS: N=545 Narrow LGS: N=102 | Broad definition: Algorithm considering: ≥1 ICD-10 diagnosis of G40 (epilepsy)/G41 (status epilepticus) and ≥1 claim of either rufinamide or felbamate (during the year of identification), OR ≥2 different ASMs in combination with ≥1 developmental delay diagnosis and no diagnosis code for competing etiologies Narrow definition: ≥1 documented G40/G41 claim before their 6th birthday | Broad LGS: 31.4 [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89]; 53% male Narrow LGS: | Epidemiology Mortality Resource Direct costs |
Chin 2021 [40] (Full) UK MEDLINE and Embase | Retrospective analysis using electronic medical records from healthcare databases: Primary care data (CPRD) linked to secondary care data (HES), and general population mortality data (ONS) | ~31 years (1987–2018) Follow-up: mean (SD; median [range]): 11.7 (8.2; 9.6 [0.2; 32.2]) years | Confirmed LGS: N=110 Probable LGS: N=146 Full cohort: N=256 | Confirmed LGS: CPRD read code for LGS Probable LGS: ICD-10 code/ CPRD read code for epilepsy Rufinamide within a year of diagnosis | Confirmed LGS: 7.0 (10.0; 3.5 [0–61]); 66% male Probable LGS: 8.9 (11.0; 4 [0–54]); 56% male Full cohort: 8.1 (10.6; 4 [0–61]); 60% male | Epidemiology Mortality Resource |
Reaven 2018 [54] (Full) (LGS vs controls) USA MEDLINE, Embase and APA PsycInfo | Retrospective insurance claims analysis: Truven Health Analytics MarketScan® Research Databases, entries for ~60 million people with commercial or Medicaid insurance coverage | 2010–2015 | Probable LGS: Commercial: N=2270 Medicaid: N= 3749 | A diagnosis code for refractory epilepsy and A diagnosis code for developmental delay/intellectual disability and A prescription for at least one selected ASM. Excluded patients with diagnosis codes for conditions suggestive of other etiologies Modified version of the algorithm developed by Piña-Garza et al [46] (above) | Commercial: 13 (9.8 [0–62]); 53.0% male Medicaid: 13 (10.5 [0–60]); 52.9% male | Resource Direct costs |
Reaven 2019 [53] (Full) (LGS vs other DEEs; seizure events vs no events) USA MEDLINE, Embase and APA PsycInfo | Probable LGS: Commercial: N=2269 Medicaid: N= 3730 | Commercial: 13 (9.8 [0–62]); 53.0% male Medicaid: 13 (10.5 [0–60]); 52.8% male | ||||
Stockl 2019 [56] (Abstract) (Hospitalizations) USA Embase | Probable LGS: Commercial: N=2520 Medicaid: N=4613 | As above, but also patients with an acute inpatient hospitalization (≥1 day LOS) | NR | Resource | ||
Stockl 2019 [55] (Abstract) (Commercial; Costs & Resource) USA Embase | Retrospective insurance claims analysis: IBM® MarketScan® Commercial & Medicaid databases | 2015–2016 | Probable LGS: Commercial: N=1296 | ≥1 ASM claim and medical claims with ≥1 diagnosis code for LGS or refractory epilepsy or ≥1 claim for clobazam or rufinamide. The LGS cohort required a diagnosis code for LGS or all of the following: oooooo≥1 diagnosis code for refractory epilepsy oooooo≥1 diagnosis code for intellectual disability/developmental delay, ooooooNo diagnosis codes that preclude LGS | Commercial: 16.5; NR | Epidemiology Resource (ASM use only) Direct costs |
Hollenack 2019 [52] (Abstract) (Medicaid; Costs & Resource USA Embase | 2014–2015 | Probable LGS: Medicaid: N= 5186 | Medicaid: 18.3; 58.2% male | |||
Hollenack 2019 [41] (Abstract) (prevalence) USA Embase | Commercial: 2016– 2017 Medicaid: 2016 | Probable LGS: Commercial: N=2273 Medicaid: N=4786 | NR | |||
François 2017 [51] (Full) USA MEDLINE | Retrospective insurance claims analysis: Truven Health MarketScan® claims databases, entries for >40 million people with commercial or Medicaid insurance coverage | 2010–2014 | LGS pre-clobazam initiation Commercial/medicare: N=1384 Medicaid: N=1365 | ≥2 medical claims with a diagnosis of generalized convulsive or non-convulsive epilepsy ≥30 days apart, or ≥1 medical claim with a diagnosis of generalized convulsive epilepsy and ≥1 medical claim with a diagnosis of non-convulsive epilepsy (≥30 days apart (ICD-9-CM codes) ≥1 of the epilepsy diagnosis codes in the primary position ≥1 medical claim with a diagnosis for developmental disorder or cognitive impairment (ICD-9-CM codes) | Commercial/medicare: 31.0 (23.2); 49.3% male Medicaid: 24.1 (17.9); 51.8% male | Resource Direct costs |
Umeno 2019 [57] (Full) Japan Embase | Retrospective study on the use of the welfare system in children with DEEs in Japan | 2015–2016 | LGS: N=30 | Children aged 0 to 16 years diagnosed at the Department of Child Neurology, Okayama University Hospital | NR | Resource (welfare system) |
Epidemiology alone | ||||||
Trevathan 1997 [44] (Full) MADDS study USA MEDLINE and Embase | Population-based, cross-sectional study: (MADDS): a multiple-source, EEG laboratory-based, case ascertainment system across Atlanta | 1975–1977 | Children with LGS: N=23 | Epilepsy Two or more seizure types that included tonic, atonic, atypical absence, and/or myoclonic seizures with multiple falls Interictal EEG that demonstrated slow spike-wave discharges | NR; 73.9% male | Prevalence |
Autry 2010 [48] (Full) MADDS study USA | 1975–2001 | LGS: N=34 | NR; NR | Mortality | ||
Sidenvall 1996 [43] (Full) Northern Sweden MEDLINE and Embase | Observational study: Active epilepsy assessed in children aged 0–16 years in an area of northern Sweden with ~ 250,000 inhabitants (~50,000 children) | 1985–1986 | LGS: N=9 | Diagnosed using standard ILAE criteria | NR; NR | Prevalence |
Rantala 1999 [42] (Full) Finland MEDLINE and Embase | Retrospective study: Children seen at the Department of Pediatrics University of Oulu | 1976–1993 | LGS: N=25 | At least two types of the most common seizure types (tonic-axial, atonic, and absence seizures) Slow spike waves | 13.0 [6.5–17.9]; 56% male | Prevalence and incidence |
Heiskala 1997 [45] (Full) Finland MEDLINE and Embase | Retrospective study: Health records from the Helsinki metropolitan area & the province of Uusimaa | 1975–1985 | LGS: N=75 | A minimum of two types of typical though nonspecific epileptic seizures (e.g. astatic seizures, tonic seizures during sleep, and atypical absence seizures) Mental deficiency Bursts of diffuse slow spike-waves in the EEG | NR; NR | Incidence |
Beilmann 1999 [39] (Full) Estonia MEDLINE | Observational study: Patients with epilepsy seen at the Tartu University Hospital, sourced through multiple methods | 1995 –1997 | NR | Diagnosed using standard ILAE criteria | NR; NR | Prevalence |
HRQoL | ||||||
Auvin 2021 [61] (Full) UK and France | Observational study: On-line surveys | 2018–2019 | Patients and/or caregivers of individuals with DEEs estimated a patient’s health state from vignettes of hypothetical patients | NA | NA; NA | Patient HRQoL: quantitative (VAS) |
Radu 2019 [62] (Abstract) NR Embase | Observational study: On-line surveys | 2018 | NA | NA; NA | Patient HRQoL: quantitative (VAS) | |
Gallop 2010 [58] (Full) US, UK & Italy MEDLINE, Embase and APA PsycInfo | Observational study: Open-ended interviews and HRQoL instruments | NR | Parents of patients with LGS recruited through support groups and websites (UK and US) and through clinicians (Italy): N=40 | NR | 12 [4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43]; 63% male | Caregiver HRQoL: Quantative (SF-36v2, HADS) and qualitative Patient HRQoL: Qualitative |
Murray 1993 [60] (Full) Australia MEDLINE, Embase and APA PsycInfo | Observational study: Questionnaires & in-depth interviews | NR | Parents of patients with LGS who attended a self-help group: N=41 | NR | 13 [3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34]; NR | Caregiver HRQoL: Qualitative |
Gibson 2014 [59] (Full) USA MEDLINE, Embase and APA PsycInfo | Observational study: General experience and parent survey | NR | Parents of patients with LGS who had contacted a support hotline: N=96 surveys returned | NR | [3.5–36 years]; NR | Caregiver HRQoL: Qualitative |