TABLE 3

Critical Appraisal Skills Program checklist results

Section and numberQuestionOptionHylander et al, 200121Furman et al, 200322Heller et al, 200718Maayan-Metzger et al, 201223Manzoni et al, 201317
Are the results of the study valid?
 1Did the study address a clearly focused issue?Yes/Can’t tell/NoYesYesYesYesYes
 2Was the cohort recruited in an acceptable way?Yes/Can’t tell/NoYesYesYesYesYes
 3Was the exposure accurately measured to minimize bias?Yes/Can’t tell/NoYesYesYesYesYes
 4Was the outcome accurately measured to minimize bias?Yes/Can’t tell/NoYesYesYesYesYes
 5aHave the authors identified all important confounding factors?Yes/Can’t tell/NoYesYes. The authors have counted liquid fortifier as preterm formula, and only the actual volume of maternal milk was counted as maternal milk.YesYesYes
 5bHave they taken account of the confounding factors in the design and/or analysis?Yes/Can’t tell/NoYes. Associations between potential variables and presence of ROP was identified through bivariate analysis.Yes. The authors have calculated the mean proportion of maternal milk of total intake (oral plus intravenous) and of oral intake.YesYesYes
 6aWas the follow-up of subjects complete enough?Yes/Can’t tell/NoNo. Missing data, through comprising only 2.4% of the total number of data elements, occurred in one-sixth of the cases.Yes. Results of all 119 infants are reported.YesYesYes
 6bWas the follow-up of subjects long enough?Yes/Can’t tell/NoYesYes. Subjects were followed through weeks 2, 4, and 6.YesYesYes
What are the results of this study?
 7What are the results of this study?Explain in 1 sentenceIncidence of ROP was significantly reduced in human milk-fed VLBW infants compared with exclusively formula-fed VLBW infants.Rates of ROP did not differ according to the amounts of maternal milk received.Neither receipt nor increasing intake of human milk was associated with a decreased risk of developing severe ROP.Lower rates of ROP were also detected in infants born at 24–28 wks who were breastfed, but the results did not reach statistical significance using univariate analysis (P <.06). Using multivariate analysis, however, ROP stage III among this subgroup was significantly lower (P <.022).Overall, ROP incidence (at any stage) was significantly lower in infants fed maternal milk compared with formula-fed neonates.
 8How precise are the results?Explain/commentDose–response effect was not observed when categories of human milk were entered into logistic regression results, as duration of feeding was not included; hence results would be precise only to some extent.Results are not precise, as sample size was not large enough to adequately assess ROP.Results are precise, as power calculation was conducted for adequate sample size of included infants.Results are precise to some extent due to the fact that study lacked precise knowledge regarding feeding days and amounts, as well as the use of human milk fortifier consisting of cow milk protein in the HM group.Good, as multivariate logistic regression controlling for potentially confounding factors to ROP at any stage at univariate analysis showed type of milk feeding retained significance, maternal milk being protective at P = .01.
 9Do you believe the results?Yes/Can’t tell/NoYesYesYesYesYes
Will the results help locally?
 10Can the results be applied to the local population?Yes/Can’t tell/NoNo. The study was limited to 1 tertiary center with extensive resources through the Milk Bank and Lactation Center available to mothers who choose to provide human milk to their VLBW infants, thus allowing relatively high rate of providing human milk to VLBW infants in the study sample.YesYesYesYes
 11Do the results of this study fit with other available evidence?Yes/Can’t tell/NoYesNo. Maternal milk has been reported to reduce rate of and severity of ROP in VLBW infants.No. HM has been associated with decreased risk of ROP.YesYes
 12What are the implications of this study for practice?Explain/commentFindings suggest a protective effect of human milk feedings against ROP after controlling for potential confounding variables.Results cannot be generalized, as sample size was low to assess the effect of maternal milk feeding on neonatal morbidities that occur at lower rates such as ROP.Limitations such as lack of data collection of eye examinations after discharge, missing data of >10% of sample who did not require surgery for ROP before discharge and did not return for follow-up visits at 18 or 30 mo corrected age, and absence of defined definition of ROP across study centers.Human milk is ROP protective even if partially administered.Exclusive maternal milk feeding since birth may prevent ROP of any stage in VLBW infants in the NICU.
Overall qualityMediumSatisfactoryMediumSatisfactoryHigh
  • VLBW, very low birth weight.