PURPOSE: Background: FEV1/FEV6 has been proposed as a diagnostic test to measure airway obstruction as an alternative to FEV1/FVC ; due to ease of use and performance. Many studies have been conducted for investigating usefulness of FEV1/FEV6 . However there is paucity of systematic reviews and meta-analyses .Purpose: To conduct a meta-analysis evaluate, in adults , diagnostic accuracy of FEV1/FEV6 for diagnosing airway obstruction.
METHODS: systematic review without language restrictions of electronic database and manual review of medical literature uptil march 2010 was done . when appropriate random effects model was used for for pooling sensitivity, specificity and likelihood ratios. Summary receiver operator characteristic ( SROC) was derived to derive overall test performance. Meta regression was done to investigate heterogeneity.
RESULTS: Fourteen studies met the inclusion criteria . There was significant heterogeneity among studies. A total of 52,537 spirometries were analysed. The pooled sensitivity was 0.877 (95% confidence interval: 0.872-0.882), the specificity was 0.969 (95% CI: 0.967-0.971), the positive likelihood ratio was 26.63 (95% CI: 17.03-41.64), the negative likelihood ratio was 0.126 (95% CI: 0.095-0.168), and the diagnostic odds ratio(DOR) was 249.54 (95% CI: 165.56-376.11). The area under the curve of the (SROC) was 0.979. meta regression showed prevalence of mild airway obstruction may have an effect on DOR.(p=0.05) No threshold effect was seen ( b= - 0.13, p= 0.48 ).
CONCLUSION: FEV1/FEV6 is a sensitive and specific test; however its sensitivity in detecting obstruction is reduced in population with borderline/mild airflow obstruction.
CLINICAL IMPLICATIONS: FEV1/FEV6 is an accurate test in detecting airway obstruction; however its performance is reduced in mild airway obstruction.
DISCLOSURE: Jaya Kala, No Financial Disclosure Information; No Product/Research Disclosure Information