1. What is the sensitivity and specificity of amniotic fluid lamellar body count in detection of respiratory distress syndrome? Faculdade de Medicina da Universidade do Porto Annual Work Class 9 Adviser: Cristina Santos

2. Introduction What is a respiratory distress syndrome? What is a test's sensitivity and specificity? Why is this meta-analysis important? What is the aim of this study?

3. What is a respiratory distress syndrome? RDS: a condition that can occur when baby is delivered before its lungs are fully mature or before surfactant is formed in sufficient quantities*. RDS: a condition that can occur when baby is delivered before its lungs are fully mature or before surfactant is formed in sufficient quantities*. Symptoms: dyspnoea with cyanosis Symptoms: dyspnoea with cyanosis dilatation of the alae nasi dilatation of the alae nasi expiratory grunt expiratory grunt etc. etc. Syndrome of respiratory difficulty caused by a deficiency of lung surfactant; Frequent in premature infants, children of diabetic mothers and infants delivered by caesarean section; * http://www.plus-size-pregnancy.org/gd/gdglossary.htm

4. Possible treatments : extra oxygen(21%) CPAP (Continuous Positive Airway Pressure), surfactant CPAP (Continuous Positive Airway Pressure), surfactant In last case the baby is intubated In last case the baby is intubated CUNNINGHAM, F.Gary et al ;William’s Obstetrics;22nd edition; Mc Graw-Hill; Medical Publishing Division; New York www.pedriatics.wisc.edu

5. What is a test's sensitivity and specificity? Sensitivity and specificity are parameters that express something about the tests’ performance; Sensitivity and specificity are parameters that express something about the tests’ performance; Sensitivity is the test ability to detect a disease when it is effectively present – true positives. If the babies suffer from respiratory distress syndrome, LBC result should be positive. Sensitivity is the test ability to detect a disease when it is effectively present – true positives. If the babies suffer from respiratory distress syndrome, LBC result should be positive. Specificity is the test ability to detect true negative. If the babies are healthy, LBC result should be negative. Specificity is the test ability to detect true negative. If the babies are healthy, LBC result should be negative.

6. Why is this meta-analysis important?

7. RDS remains a common cause of neonatal morbidity and mortality. Consequently fetal lung maturity (FLM) testing plays an important role in establishing obstetric management strategies Several biophysical and biochemical laboratory tests were developed The most widely used are Lecithin toSphingomyelin(L/S) ratio and the quantification of phosphatidylglycerol (PG) in amniotic fluid Khazardoost S, Yahyazadeh H, Borna S, Sohrabvand F, Yahyazadeh N, Amini E.Khazardoost S, Yahyazadeh H, Borna S, Sohrabvand F, Yahyazadeh N, Amini E.; Amniotic fluid lamellar body count and its sensitivity and specificity in evaluating of fetal lung maturity. J Obstet Gynaecol. 2005 Apr;25(3):257-9. PMID: 16147729 [PubMed - indexed for MEDLINE] Khazardoost S, Yahyazadeh H, Borna S, Sohrabvand F, Yahyazadeh N, Amini E.

8. However L/S ratio and PG estimate are unavailable at several instituitions due to economic and logistics reasons In this context LBC might be a viable alternative Lamellar bodies can easily be counted using commercial blood cell analysers Therefore LBC is very test Therefore LBC is very quick, simple and inexpensive test Khazardoost S, Yahyazadeh H, Borna S, Sohrabvand F, Yahyazadeh N, Amini E.Khazardoost S, Yahyazadeh H, Borna S, Sohrabvand F, Yahyazadeh N, Amini E.; Amniotic fluid lamellar body count and its sensitivity and specificity in evaluating of fetal lung maturity. J Obstet Gynaecol. 2005 Apr;25(3):257-9. PMID: 16147729 [PubMed - indexed for MEDLINE] Khazardoost S, Yahyazadeh H, Borna S, Sohrabvand F, Yahyazadeh N, Amini E.

9. What is the aim of this study? The aim of our study is a meta-analysis of the articles that evaluate the specificity and sensitivity of amniotic fluid lamellar body count (LBC) in detection of respiratory distress syndrome (RDS), providing by this mean reliable information to all health personnel about this test. The aim of our study is a meta-analysis of the articles that evaluate the specificity and sensitivity of amniotic fluid lamellar body count (LBC) in detection of respiratory distress syndrome (RDS), providing by this mean reliable information to all health personnel about this test.

10. Study Design Meta-analysis Meta-analysis All studies results were analyzed in order to answer the question: All studies results were analyzed in order to answer the question: “What’s the specificity and sensitivity of amniotic fluid lamellar body count in detection of respiratory distress syndrome?” “What’s the specificity and sensitivity of amniotic fluid lamellar body count in detection of respiratory distress syndrome?”

11. Work steps: Work steps: 1. Search for literature 2. Use predefined Inclusion/Exclusion Criteria to select the article 3. Evaluate quality of articles 4. Extract data 5. Statistical analysis of data

12. Research methods Database: Medline and SCOPUS Limits: publications until 2005/10; Humans The search aimed at finding the most evidence which could be useful in estimating the sensitivity and specificity of lamellar body count from the amniotic fluid in detection of respiratory distress syndrome in Newborn

13. Search process Sensitivity and Specificity Sensitivity and Specificity Using a recommended search strategy* (sensitiv*[Title/Abstract] OR sensitivity and specificity[MeSH Terms] OR diagnos*[Title/Abstract] OR diagnosis[MeSH:noexp] OR diagnostic * [MeSH:noexp]) MeSH (Medical Headin Subject): sensitivity and specificity[MeSH Terms]; diagnosis[MeSH:noexp; diagnostic* [MeSH:noexp] Search 1: N=1962714 articles Haynes RB, Wilczynski NC for the Hedges Team. Optimal search strategies for retrieving scientifically strong studies of diagnosis from MEDLINE: analytical survey. BMJ. 2004 May 1;328(7447):1040 Medline

14. We attempted to find most studies containing the following criteria: We attempted to find most studies containing the following criteria: 1. diagnosis studies; 2. all diagnosis studies related to respiratory distress syndrome in newborn (RDS) a.k.a. “(hyaline membrane disease”), directly related to lung maturity (which is behind the RDS and can be, in some cases by amniocentesis); 3. obtain diagnosis studies related to the given intervention, lamellar body count. Query: (sensitiv*[Title/Abstract] OR sensitivity and specificity[MeSH Terms] OR diagnos*[Title/Abstract] OR diagnosis[MeSH:noexp] OR diagnostic*[MeSH:noexp] OR diagnosis, differential[MeSH:noexp] OR diagnosis[Subheading:noexp]) AND ("respiratory distress syndrome, Newborn" [MeSH] OR "lung maturity" OR "respiratory distress syndrome" OR "FLM" OR “surfactant” OR “hyaline membrane”) AND ("lamellar body count" OR "lamellar bodies") N= 42 Articles

15. SCOPUS Query: “lamellar body count” AND “respiratory distress syndrome” No other articles were found that hadn’t already been included in the Medline search.

16. Critics on research methods The research was based only on two databases, apart from other data source such as Cochrane central or manual research.

17. 3 independent reviewers read the titles and abstract selecting them according to the inclusion/exclusion criteria. Title and abstract review Full text review 2 independent reviewers

18. Inclusion criteria Studies’ inclusion was processed by the selection of articles that evaluated sensitivity and specificity of diagnosis method of amniotic fluid lamellar body count, in the detection of Respiratory Distress Syndrome. Studies’ inclusion was processed by the selection of articles that evaluated sensitivity and specificity of diagnosis method of amniotic fluid lamellar body count, in the detection of Respiratory Distress Syndrome.  The articles included were written in the following languages known by the revisers: English, French, Spanish and Portuguese.

19. Exclusion criteria In a second stage of analysis, articles were excluded according to the following criteria: compare different techniques not referring to lamellar body count tests; compare different techniques not referring to lamellar body count tests; include the results of lamellar body count along with the results of other tests, becoming impossible to calculate the sensitivity and specificity of the test; include the results of lamellar body count along with the results of other tests, becoming impossible to calculate the sensitivity and specificity of the test; omit the results namely the sensitivity and specificity of lamellar body count. omit the results namely the sensitivity and specificity of lamellar body count.

20. Quality analysis of the studies In a third stage the selected articles were analysed by two independent revisers in order to evaluate their quality using STARD checklist [3], used for evaluation of diagnostic studies. In a third stage the selected articles were analysed by two independent revisers in order to evaluate their quality using STARD checklist [3], used for evaluation of diagnostic studies. To every affirmative topic was given 1 point and to negative ones zero points. To every affirmative topic was given 1 point and to negative ones zero points. The evaluation of quality was based on the sum of points resultant from article analysis, within a maximum of 25 points per article. The evaluation of quality was based on the sum of points resultant from article analysis, within a maximum of 25 points per article. Articles quality was compared using the mean of the two revisers results. Articles quality was compared using the mean of the two revisers results. [3] Towards complete and accurate reporting of studies of diagnostic accuracy: the STARD initiative. The Standards for Reporting of Diagnostic Accuracy Group. Croat Med J. 2003 Oct;44(5):635-8. [3] Towards complete and accurate reporting of studies of diagnostic accuracy: the STARD initiative. The Standards for Reporting of Diagnostic Accuracy Group. Croat Med J. 2003 Oct;44(5):635-8.

21. Data extraction Article ID Article ID True Positives, True Negatives; False positives; False negatives True Positives, True Negatives; False positives; False negatives Values of: Values of: Sensitivity Sensitivity Specificity Specificity Cut-off points Cut-off points

22. Statistical analysis......of the agreement between reviewers in title, abstract -> Kappa Cohen test...of the agreement between reviewers in title, abstract -> Kappa Cohen test...of the agreement between reviewers in full text review-> Kappa Cohen test...of the agreement between reviewers in full text review-> Kappa Cohen test...of the agreement in quality measure -> ICC (continuous scale)...of the agreement in quality measure -> ICC (continuous scale) Software used: SPSS 14.0 Software used: SPSS 14.0 *Devillé, Walter et all - Conducting systematic reviews of diagnostic studies - Didactic guidelines; BMC Medical Research Methodology 2002, 2:9 *Devillé, Walter et all - Conducting systematic reviews of diagnostic studies - Didactic guidelines; BMC Medical Research Methodology 2002, 2:9 Data analysis: Software used: MetaDiSc 1.2

23. Results

24. 42 articles 42 articles Abstract review 14 included 28 excluded 3 are meta-analysis. One for comparison, the other 2 don’t mention what is pretended 7 don’t mention neither sensitivity nor specificity 16 don’t refer lamellar body count 1 has insufficient data 1 doesn’t refer the use of this method in detection of this disease Full text review 4 not found 3 excluded 7 included for meta-analysis

25. Agreement Cohen-Kappa in title and abstract evaluation: Cohen-Kappa in title and abstract evaluation: Cohen-Kappa full-text evaluation: 1.000 Cohen-Kappa full-text evaluation: 1.000 Based on the conclusions of Landis and Koch (1977), we may classify these agreements as good. Based on the conclusions of Landis and Koch (1977), we may classify these agreements as good. 1st vs 2nd - 0,618 1st vs 3rd - 0,777 2nd vs 3rd - 0,727

26. Quality evaluation ICC = 0.787 ICC = 0.787 Mean quality: 15 Mean quality: 15 Lower value: 11 Lower value: 11 Highest value: 22 Highest value: 22

27. Sensitivity and Specificity table Sensitivity and Specificity AuthorCut-offSen[95% Conf. Iterval.]Spef[95% Conf. Iterval.] Quality (mean) Khazardoost [2]500000,850,62-0,970,700,57-0,8117.5 Beinlich [22]300000,820.63-0.941,000,94-1,0015 Ghidini [21]370000,940.71-1.000,640,52-0,7415 DeRoche [20]370000,820.63-0.941,000,94-1,0015 Dalence [19] 300001.000.79-1.000,640,54-0,73 22 100000.750.48-0.930,950,90 - 0,98 Ross [16] 415000.910.77-0.970,880,79- 0,94 19.5 320000.910.77-0.970,850,76-0,92 240000.790.63-0.901,000,96-1,00 210000.710.55-0.841,000,96 -1,00 Aal [23] 15000 0,780,56 - 0,931,000,93-1,00 11 18000 0,780,56 - 0,931,000,93-1,00 41000 1,000,85 - 1,000,860,73-0,94 50000 1,000,85 - 1,000,740,60-0,85

28. Cut-off = 30000 Heterogeneity present on both sensitivity and specificity (p<0.05)Heterogeneity present on both sensitivity and specificity (p<0.05) Why? Difference on qualityWhy? Difference on quality Dalence et al : 22Dalence et al : 22 Beilinch et al : 15Beilinch et al : 15

29. Cut-off= 37000 Heterogeneity present on specificity (p<0.05) Homogeneity present on sensitivity (p= 0.227) Pooled sensitivity= 0.87

30. Possible factors… Cut-off point Quality of the article Blood presence (amniocentesis) Vaginal mucus Equipment Confounding factors Ex:Transient tachypnea

31. Cut-off=50000 Heterogeneity present on Sensitivity (p<0.05) Difference on quality: Khazardoost – 17.5 Aal - 11 Homogeneity present on Specificity (p=0.642) Pooled Specificity=0.72

32. According to a Protocol*: Cut-off points under 15000/µL Higher Specificity Cut-off points bigger than 50000/µL Higher Sensitivity * Neerhoof MG, Dohnal JC, Ashwood ER, Lee IS, Anceschi MM. Lamellar body counts: a consensus on protocol. Obstet Gynecol.2001 Feb; 97(2):318-20 Specificity: 0.947-1.000 Sensitivity: 0.850-1.000

33. SROC curve

34. Conclusions

35. Some study Limitations: Not all the articles were found; Different cut-off points; Presence of heterogeneity on the sample.

36. Differences in the experimental protocol lead to different results* Differences in the experimental protocol lead to different results* Lack of similar cut-offs make statistical analysis difficult* Lack of similar cut-offs make statistical analysis difficult* Materials used affect results ∞ Materials used affect results ∞ *Neerhof MG, Dohnal JC, Ashwood ER, Lee IS, Anceschi MM. Lamellar body counts: a consensus on protocol. Obstet Gynecol. 2001 Feb; 97(2):318-20. ∞ ∞ Bowie LJ, Shammo J. Lamellar body number density and the prediction of respiratorydistress syndrome. Am J Clin Pathol 1991; 95:781-6

37. Cut-off point=37000 pooled sensitivity=0.87 Cut-off point=50000 pooled specificity=0.72 Lamellar body count is:  Quick  Simple  Inexpensive  Good diagnosis test