RAMB Maio/Junho 2015

imões

198

ssoc

ras

2015; 61(3):196-202

tent (

). For critical analysis of non-randomized studies,

including prospective observational studies, we used the

Newcastle-Ottawa scale.

For results with evidence available, whenever possi-

ble the following specific items are defined: population,

intervention, outcomes, the presence or absence of ben-

efit and/or damage and controversies.

Cost issues will not be included in the results.

The results will be presented preferably in absolute

data, absolute risk, number needed to treat (NNT) or

number needed to harm (NNH), and occasionally in mean

and standard deviation.

References related to included and excluded studies

are shown in section References.

TABLE 2

Worksheet used for description of studies

included and exposure of the results.

Worksheet for description of studies and exposure of the

results

Evidence included

Study design

Population selected

Time of follow-up

Outcomes considered

Expression of results: percentage, risk, odds, hazard ratio

TABLE 3

Critical assessment script for randomized

controlled trials (checklist).

Study data

Reference, study design, Jadad,

strength of evidence

Sample size calculation

Estimated differences, power,

significance level, total number

of patients

Patient selection

Inclusion and exclusion criteria

Patients

Recruited, randomized,

prognostic differences

Randomization

Description and blinded allocation

Patient follow-up

Time, losses, migration

Treatment protocol

Intervention, control and blinding

Analysis

Intention to treat, analyzes of

intervention and control

Outcomes considered

Primary, secondary, measuring

instrument of the outcome of

interest

Result

Benefit or harm in absolute

data, benefit or harm on

average

Clinical question

Is performance of elective cesarean section in case of ce-

sarean delivery in a previous pregnancy related with less

maternal morbidity and mortality compared with vagi-

nal deliver?

Evidence selected

TABLE 4

Selection process.

Type of publication

Included

Randomized clinical trials

Current cohort studies

Non-current cohort studies

6-14

The main reasons for the exclusion of studies were: study

design other than observational longitudinal clinical tri-

als (retrospective or prospective) or experimental (con-

trolled clinical trials, randomized or not); absence of the

full text; selection for the performance of elective cesare-

an section in women not considered eligible to trial of la-

bor; studies that did not assess the two approaches simul-

taneously; studies that included populations with unique

characteristics such as twin pregnancies, breech delivery

and two or more cesarean section scars.

Results of the evidence selected

Of the 584 articles initially retrieved, nine were selected

to support the synthesis of evidence regarding maternal

morbidity and mortality related to type of delivery in case

of cesarean section in a previous pregnancy. Studies in-

cluded are shown in Table 4.

1. Crowther CA, et al. (

)

•

Design: concurrent observational longitudinal

study with nested randomized clinical trial.

•

Population: 2,345 pregnant women with one pre-

vious cesarean section and eligible for planned vag-

inal delivery were recruited from 14 centers. Pa-

tients with fetuses at term (gestational age ≥37

weeks) were allocated according to preference

(n=2,323) or randomized (n=22) into groups for

planned vaginal delivery or cesarean section.

•

Outcome: to assess, as the primary outcome, peri-

natal and neonatal morbidity and mortality, exclud-

ing cases related to fatal congenital anomalies. The

analysis included birth trauma (bone fractures, sub-

dural hematoma, brain or intraventricular hemor-

rhage), spinal cord injury, peripheral nerve injury,

seizures (within 24 hours of birth or need for two

or more drugs to control) Apgar score <4 at five

minutes, need for assisted ventilation, stay in neo-

natal intensive care unit for longer than four days.