Diagnostic Value Of Laser Doppler Imaging(LDI)for The Burn Depth: A Meta-analysis

Background and objective Burns are common in daily production and life.Early correct diagnosis of burn depth is vital to evaluating the patient's condition,helping doctors to make the choice of treatment and predicting prognosis.Laser Doppler imaging(LDI)is one of the technologies that can objectively diagnose the burn depth,but the number of patients or wounds in the related studies were not sufficient.The aim of this paper was to systematically evaluate the value of LDI in diagnosing burn depth with Meta-analysis.Methods Databases including PubMed,Cochrane Library,EMbase,Science Direct,Chinese Biomedical Literature Database,Chinese Journals Full-text Database,WanFang Database,VIP Database were searched to obtain the published trials of LDI in diagnosing burn depth from the establishment of each database to January 2016.Two reviewers independently screened the literature,extracted data and evaluated the methodological quality of the included studies.Data were processed with Meta-DiSc 1.4 statistical software.The heterogeneity among the included studies were evaluated.The pooled estimates of LDI in diagnosing burn depth of the included studies,including sensitivity,specificity,positive likelihood ratio,negative likelihood ratio,diagnostic odds ratio,as well as the area under the curve of summary receiver operating characteristics and index of Q* were calculated.The stability of the overall pooled estimates of the included studies was validated by sensitivity analysis.The sources of heterogeneity among the included studies were sought through subgroup analysis.The publication bias caused by the results of the included studies was evaluated by drawing the Deek 's funnel plot.Results A total of 11 studies conforming to the inclusion criteria,involving 485 burn wounds,were included.Two of the included studies had low risk of bias,while the other 9 studies had high/unclear risk of bias.In applicability concern aspect,one of these included studies had high/unclear concerns,while the other 10 studies had low concerns.Overall,the methodological quality of included studies was moderate.There was no heterogeneity caused by threshold effects among the included studies,but there was high heterogeneity caused by non-threshold effects among the included studies.The overall pooled sensitivity,specificity,positive likelihood ratio,negative likelihood ratio,and diagnostic odds ratio of the included studies on LDI in diagnosing burn depth were 0.94(with 95% confidence interval 0.91-0.97),0.96(with 95% confidence interval 0.92-0.98),11.35(with 95% confidence interval 5.08-25.35),0.09(with 95% confidence interval 0.06-0.14),229.32(with 95% confidence interval 90.22-582.91)respectively.The area under the curve of summary receiver operating characteristics was 0.98,with index of Q* as 0.94.Sensitivity analysis showed that the results of the overall pooled estimates of the included studies was stable.The risk of bias of the selection of the patients,equipment type of LDI,and the selection of reference standard might be the sources of the heterogeneity of the included studies.The Deek 's funnel plot indicated that there was publication bias caused by the results of the included studies(P<0.05).Conclusions LDI has high sensitivity,specificity,positive likelihood ratio,diagnostic odds ratio and index of Q*,large area under the curve of summary receiver operating characteristics,and low negative likelihood ratio in diagnosing burn depth,which has relatively high diagnostic value and could be widely used in diagnosing burn depth.The age of patients was not the factor which influence the accuracy of LDI results,indicated that LDI should also be applied in pediatric burns.