Primidone AND Phenobarbital (All indications) updated on 04-22-2025

Learning disorders

R analysis
id Study   Lib. in paper Exposition period    Study type 
 Control type 
 
Tags OR 95%CI x1/n1 x0/n0 no cases no exposed ROB Ref.
S19472
R83088		 Straub (Controls unexposed, sick) (Phenobarbital) (Epilepsy), 2026 Learning difficulty - ICD-10 codes: F81.0, F81.2, F81.8x, R48.0 - Mean follow up (full cohort): 3.4 years during pregnancy (anytime or not specified) retrospective cohort (claims database) unexposed, sick Adjustment: Yes 0.47 [0.09;2.32] -/249   43/8,887 - 249
ref
S9554
R33783		 Elkjaer (Phenobarbital), 2018 Mathematics at 6th grade during pregnancy (anytime or not specified) population based cohort propective unexposed (general population or NOS) Adjustment: Yes extrapolated (cont. endpoint) 1.20 [0.98;1.46] -/54   -/241,647 - 54
ref
S9564
R33826		 Van der Pol (Phenobarbital) (Controls unexposed, disease free), 1991 Poor arithmetic (Dutch test) throughout pregnancy prospective cohort unexposed, disease free excluded Adjustment: No Matched 13.13 [1.66;103.68] C
excluded (control group) 		3/7   2/37 5 7
ref
S9565
R33852		 Van der Pol (Phenobarbital) (Controls unexposed, sick), 1991 Poor spelling (Dutch test) throughout pregnancy prospective cohort unexposed, sick Adjustment: No 13.75 [1.48;127.48] C 5/7   2/13 7 7
ref
Total 3 studies 1.52 [0.41;5.69] 7 310
x1: number of endpoints among exposed, n1: number of exposed; x0: number of endpoints among non exposed, n0: number of non exposed; C: calculated odds ratio from numbers of events and effectives

Forest plot

StudyTE95% CIn casesn exposedweightROBABCDEF Straub (Controls unexposed, sick) (Phenobarbital) (Epilepsy), 2026Straub, 2026 1 0.47[0.09; 2.32]-24929%ROB confusion: seriousROB selection: lowROB classification: moderateROB missing: unclearROB mesure: criticalROB reporting: moderate Elkjaer (Phenobarbital), 2018Elkjaer, 2018 2 1.20[0.98; 1.46]-5450%ROB confusion: seriousROB selection: moderateROB classification: criticalROB missing: unclearROB mesure: moderateROB reporting: moderate Van der Pol (Phenobarbital) (Controls unexposed, sick), 1991Van der Pol, 1991 3 13.75[1.48; 127.48]7721%ROB confusion: criticalROB selection: lowROB classification: moderateROB missing: criticalROB mesure: moderateROB reporting: moderate Total (3 studies) I2 = 66% 1.52[0.41; 5.69]73100.250.01.0ROB: A: confounding, B: selection, C: classification, D: missing, E: measurement, F: reportinglow,moderate,serious,critical,unclear,

1: Controls unexposed, sick) (Phenobarbital) (Epilepsy; 2: Phenobarbital; 3: Phenobarbital) (Controls unexposed, sick;

Sensitivity analysis

SubsetTE95% CIn casesn exposedkI2 Type of studies cohort studiescohort studies 1.52[0.41; 5.69]731066%NAStraub (Controls unexposed, sick) (Phenobarbital) (Epilepsy), 2026 Elkjaer (Phenobarbital), 2018 Van der Pol (Phenobarbital) (Controls unexposed, sick), 1991 3 case control studiescase control studies 0 Type of controls unexposed (disease free or unspecified)unexposed (disease free or unspecified) 1.20[0.98; 1.46]-54 -NAElkjaer (Phenobarbital), 2018 1 unexposed, sickunexposed, sick 2.32[0.09; 63.27]725683%NAStraub (Controls unexposed, sick) (Phenobarbital) (Epilepsy), 2026 Van der Pol (Phenobarbital) (Controls unexposed, sick), 1991 2 Tags Adjustment   - No  - No 13.75[1.48; 127.48]77 -NAVan der Pol (Phenobarbital) (Controls unexposed, sick), 1991 1   - Yes  - Yes 1.08[0.60; 1.94]-30321%NAStraub (Controls unexposed, sick) (Phenobarbital) (Epilepsy), 2026 Elkjaer (Phenobarbital), 2018 2 extrapolated (cont. endpoint)extrapolated (cont. endpoint) 1.20[0.98; 1.46]-54 -NAElkjaer (Phenobarbital), 2018 1 All studiesAll studies 1.52[0.41; 5.69]731066%NAStraub (Controls unexposed, sick) (Phenobarbital) (Epilepsy), 2026 Elkjaer (Phenobarbital), 2018 Van der Pol (Phenobarbital) (Controls unexposed, sick), 1991 30.250.01.0

Publication bias and p-hacking diagnosis

funnel plot

Funnel plot not drawn. Less than 3 points.

Asymetry test p-value = NaN (by Egger's regression)

not enought points

p values plot

Funnel plot not drawn. Less than 3 points.

Sub-groups analysis using all included studies

excluded 9564

Sub-groupsTE95% CIn casesn exposedkI2ROB type of controls unexposed controls (disease free or unspecified)unexposed controls (disease free or unspecified) 3.15[0.32; 31.46]56180%NAElkjaer (Phenobarbital), 2018 Van der Pol (Phenobarbital) (Controls unexposed, disease free), 1991 2 unexposed, sick controlsunexposed, sick controls 2.32[0.09; 63.27]4125683%NAStraub (Controls unexposed, sick) (Phenobarbital) (Epilepsy), 2026 Van der Pol (Phenobarbital) (Controls unexposed, sick), 1991 20.510.01.0