4. Datos y metodología
5.2 Modelos de regresion logísticos
5.2.2 Presencia de algún problema escolar
The overall evidence from included studies had poor methodological quality as assessed by the QUIPS tool (see Figure 5).264 None of the studies were at low risk of bias in all six domains.
In 10 of 17 studies (59%), risk of bias was high in two or more domains and in 4 of 17 studies (24%), risk of bias was high in one domain. The domain with the greatest risk of bias was study confounding. Thirteen of the seventeen studies (76%) were at high risk because the study designs did not account for key potential confounders.274, 279-281, 283, 284, 287, 90, 276, 277, 103, 278, 39 The remaining four studies were at moderate risk as there was information on some, but not
all, confounding factors.275, 282, 285, 286 Nine studies (53%) were at high risk of selection bias 274- 277, 280, 281, 90, 278, 103 and the remaining eight studies were at moderate risk,286, 287, 279, 282-285, 39 as
the recruitment methods were not fully stated and/or baseline characteristics were not adequately described. Two studies were at high risk of bias for the statistical analysis and reporting domain103, 280 and eight were at moderate risk,275, 286, 277, 278, 281, 282, 285, 276 as there was
selective reporting and/or insufficient reporting of the number of cases in each prognostic group.
Of the five studies on the serotypes associated with progression from neonatal GBS colonisation to EOGBS, two were at high,275, 277 and three were at moderate287, 39, 286 risk of
bias for study participation, while three were at high,277, 287, 39 and two were at moderate risk
of bias for study confounding.275, 286 One of these studies was also at high risk of bias for
prognostic factor measurement,275 and one for outcome measurement as there was no
information provided on the definition and measurement of EOGBS or serotyping procedures.39 The study on the serotypes associated with GBS transmission from mother to
neonate had high risk of bias for study participation and study confounding.274 Similarly, the
risk of bias for study confounding in bacterial load studies was high in nine of the 11 studies279- 281, 283, 284, 90, 276, 278, 103 and moderate in the remaining two studies.282, 285 Six of these studies
were also at high risk of bias for study participation280, 281, 90, 276, 103, 278 while five were at
moderate risk.279, 282-285 One bacterial load study had high risk of bias for study attrition and
outcome measurement276 and two had high risk of bias for statistical analysis and reporting.103, 280 Only prognostic factor measurement was at low risk of bias across all bacterial load studies.
The study on C-protein antigen was at high risk of bias for study participation and study confounding, as well as moderate risk of bias for statistical analysis and reporting.277
Figure 5. Quality assessment across included studies, according to the QUIPS tool264
0 2 4 6 8 10 12 14 16 18
StudyParticipation StudyConfounding StudyAttrition StatisticalAnalysisandReporting PrognosticFactorMeasurement OutcomeMeasurement
StudyParticipation StudyConfounding StudyAttrition StatisticalAnalysisand Reporting
PrognosticFactor
Measurement OutcomeMeasurement
Low 0 0 8 7 14 10
Moderate 8 4 8 8 2 5
High 9 13 1 2 1 2
89
Table 10. Characteristics of studies Study
Country Design Participant characteristics and GBS culture method outcome Definition and measurement of
Serotype
Maternal GBS colonisation to neonatal GBS colonisation or EOGBS
Al-Sweih 2005274
Kuwait Prospective cohort study 124 women colonised with GBS on vaginal-anorectal swabs in labour (Selective culture) Neonates colonised with GBS on surface swabs at unspecified time (Selective culture)
Neonatal GBS colonisation to EOGBS disease
Baker 1973275
US
Cohort study 66 neonates: 54 asymptomatic neonates colonised with GBS on surface culture at mean age of 13.8 hours (Selective culture), 13 neonates with EOGBS disease (one patient in both groups)
EOGBS disease: ≤ 10 days (all infants developed symptoms in the first five days of life)
Baker 1974286
US Case control study Neonates (numbers unclear): 53 asymptomatic neonates colonised with GBS on surface swabs at <3 days, 15 neonates with EOGBS meningitis, Not known number of neonates with EOGBS sepsis
EOGBS sepsis (clinical symptoms and pre-mortem blood cultures or post- mortem heart and lung cultures in neonates with pneumonia) or meningitis (CSF culture) ≤5 days
Chun 1991277
US Case-controlled study
121 neonates: 74 asymptomatic neonates colonised with GBS at birth on surface
swabs, 47 EOGBS sepsis EOGBS sepsis: < 7 days, blood and CSF culture Embil 1987287
Canada Prospective cohort study 55 strains from 54 neonates: 42 asymptomatic neonates colonised with GBS on surface swabs within 1 hour of birth (Selective culture), 12 symptomatic GBS Symptomatic EOGBS < 3 days Madzivhandila
201139
South Africa
Prospective
cohort study 525 neonates: 389 neonatal isolates colonised on surface swab shortly after birth (Standard culture), 136 neonates with invasive EOGBS EOGBS: < 7 days, blood and CSF culture Reaction to C-protein
Neonatal GBS colonisation to EOGBS
Chun 1991277
US
Case- controlled study
121 neonates: 74 asymptomatic neonates colonised with GBS at birth on surface swabs, 47 EOGBS sepsis
EOGBS sepsis: < 7 days, blood and CSF culture
C protein ß antigen gene
90
Study Country
Design Participant characteristics and GBS culture method Definition and measurement of
outcome Chun 1991277
US Case-controlled study
121 neonates: 74 asymptomatic neonates colonised with GBS at birth on surface
swabs, 47 EOGBS sepsis EOGBS sepsis: < 7 days, blood and CSF culture Bacterial load: Number of positive sites
Maternal GBS colonisation to neonatal GBS colonisation and EOGBS
Hoogkamp 1982280
Netherlands Prospective cohort study 46 women colonised with GBS on throat, nose, vagina, cervix, rectum, and midstream urine swabs in labour (Selective culture) Neonates colonised with GBS on surface swab at < 6 hours of birth (Selective swab)
Neonatal GBS colonisation to EOGBS
Dillon 1987278
US Prospective cohort study 1448 neonates colonised with GBS on surface culture within 1 hour of birth (Selective culture) EOGBS: < 3 days, symptoms and blood, CSF, urine, and other clinical specimens Pass 197990
US Prospective cohort study 290 neonates colonised with GBS on surface swabs 1-2 hours after birth (Selective culture) EOGBS: blood and CSF culture Bacterial load: Number of colony counts per plate
Maternal GBS colonisation to neonatal GBS colonisation and EOGBS
Easmon 1985103
England Prospective cohort study 140 women colonised with GBS on vaginal swabs in labour (Selective and standard culture) 38 neonates colonised with GBS on surface culture within 24 hours of birth and/or on discharge from hospital (Selective culture)
141 women colonised with GBS on rectal swabs in labour (Selective and
standard culture) 39 neonates colonised with GBS on surface culture within 24 hours of birth and/or on discharge from hospital (Selective culture)
Hoogkamp 1982280
Netherlands Prospective cohort study 46 women colonised with GBS on throat, nose, vagina, cervix, rectum, and midstream urine swabs in labour (Selective culture) Neonates colonised with GBS on surface swab at < 6 hours of birth (Selective swab)
Neonatal GBS colonisation to EOGBS
Gerards 1985279
Netherlands Cohort study 68 neonates: 47 neonates colonised with GBS on surface swabs immediately after admission to NICU (Selective culture), 21 EOGBS EOGBS: < 7 days sepsis symptoms with GBS cultured from normally sterile culture
66 neonates: 47 neonates colonised with GBS on surface swabs immediately
91
Study Country
Design Participant characteristics and GBS culture method Definition and measurement of
outcome Bacterial load - Colony-forming units (CFU) per ml
Maternal GBS colonisation to neonatal GBS colonisation and EOGBS
Jones 1984281
US
Prospective cohort study
130 women colonised with GBS on vaginal swabs at labour (Selective culture) Neonates colonised with GBS on surface swabs at unspecified time (Selective culture)
Jones 1984281
US Prospective cohort study 130 women colonised with GBS on vaginal swabs at labour (Selective culture) EOGBS: 2 neonates were blood culture positive, Probable EOGBS: 1 had symptoms and surface culture positive
Persson 1986284 Sweden Secondary analysis combined with a prospective cohort study
64 women colonised with GBS on urine swab in labour (Selective culture) 12 neonates colonised with GBS on surface culture < 5 days (Selective culture)
Sensini 1997285
Italy
Prospective cohort study
260 women colonised with GBS on lower vaginal swabs in labour (Selective culture)
108 neonates colonised with GBS on surface culture before first bath (Selective culture)
1 neonate with EOGBS sepsis < 24 hours , blood culture and sepsis symptoms
Bacterial load - Other
Maternal GBS colonisation to neonatal GBS colonisation and EOGBS
Boyer 1983276
US Prospective cohort study 207 women colonised with GBS on vaginal swabs in labour who gave birth to 209 neonates (Selective culture) Neonates colonised with GBS on surface swabs in the delivery room EOGBS
Morales 1986
US283 Untreated control group
of RCT
128 women colonised with GBS at labour identified by a rapid slide
coagglutination test on selective vaginal culture 59 term neonates colonised with GBS on surface swabs at delivery 3 GBS sepsis in term neonates
Positive body fluid Morales 1987282
92
Study Country
Design Participant characteristics and GBS culture method Definition and measurement of
outcome 48 women colonised with GBS at labour identified by latex agglutination on
selective vaginal culture 13 preterm neonates with GBS sepsis, blood, CSF, or urine culture, and oropharynx cultures with radiographic and clinical signs of infection