Tramadol (versus unexposed) updated on 07-09-2025

Nervous system anomalies

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.
S18427
R78019		 Ferrer, 2025 Nervous system anomalies at least 1st trimester retrospective cohort (claims database) unexposed (general population or NOS) Adjustment: No 2.13 [0.88;5.16] C 5/999   360/152,811 365 999
ref
S13280
R51153		 Sørensen, 2022 Nervous system malformations 1st trimester population based cohort retrospective unexposed (general population or NOS) Adjustment: Yes 1.85 [0.96;3.56] 13/3,796   28/15,111 41 3,796
ref
Total 2 studies 1.94 [1.15;3.29] 406 4,795
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 Ferrer, 2025Ferrer, 2025 2.13[0.88; 5.16]36599935%ROB confusion: criticalROB selection: lowROB classification: criticalROB missing: unclearROB mesure: moderateROB reporting: moderate Sørensen, 2022Sørensen, 2022 1.85[0.96; 3.56]413,79665%ROB confusion: moderateROB selection: moderateROB classification: criticalROB missing: moderateROB mesure: moderateROB reporting: moderate Total (2 studies) I2 = 0% 1.94[1.15; 3.29]4064,7950.55.01.0ROB: A: confusion, B: selection, C: classification, D: missing, E: measurement, F: reportinglow,moderate,serious,critical,unclear,

Sensitivity analysis

SubsetTE95% CIn casesn exposedkI2 Type of studies cohort studiescohort studies 1.94[1.15; 3.29]4064,7950%NAFerrer, 2025 Sørensen, 2022 2 case control studiescase control studies 0 Type of controls unexposed (disease free or unspecified)unexposed (disease free or unspecified) 1.94[1.15; 3.29]4064,7950%NAFerrer, 2025 Sørensen, 2022 2 Tags Adjustment   - No  - No 2.13[0.88; 5.16]365999 -NAFerrer, 2025 1   - Yes  - Yes 1.85[0.96; 3.56]413,796 -NASørensen, 2022 1 All studiesAll studies 1.94[1.15; 3.29]4064,7950%NAFerrer, 2025 Sørensen, 2022 20.55.01.0

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

Sub-groupsTE95% CIn casesn exposedkI2ROB type of controls unexposed controls (disease free or unspecified)unexposed controls (disease free or unspecified) 1.94[1.15; 3.29]4064,7950%NAFerrer, 2025 Sørensen, 2022 20.510.01.0