Decompression illness reported in a survey of 429 recreational divers

Background: The purpose of this study was to investigate the influence of diving experience and diving techniques on the lifetime incidence of decompression illness (DCI). Methods: Attendants of three diving medical symposia voluntarily answered a questionnaire about their age, gender, medical history, diving experience, diving habits, diving certification levels, and diving associated incidents (cross-sectional survey). Results: Out of 650 divers, 429 completed the questionnaire. The study population consisted of experienced divers with an average of 670 dives. The majority of the divers were certified diving instructors (43%). There were 37 participants (8.7%) who were classified as technical divers with an average of 1193 logged dives. There was an overall lifetime incidence of DCI of I per 5463 dives. The complete study group showed an increased lifetime incidence of DCI with decreased diving experience (1.97-fold to 8.17-fold higher). Of the divers, 27% reported severe DCI with neurological symptoms. The lifetime incidence for severe DO was I in 20,291 dives. Again, lifetime incidence for severe DO was increased with decreased diving certification level (1.1-fold to 13.7-fold higher). Technical divers showed a DO lifetime incidence of I to 8591 dives compared to the non-technical divers with a lifetime incidence of 1 to 5077 dives (not significant). Conclusion: In our study population, the lifetime incidence of DCI was increased in divers with less diving experience. If further studies confirm this finding, diving federations should be encouraged to intensify their efforts of educating divers and should limit diving time and depth in inexperienced divers.