>There are three major classes of scientific research in scuba diving: experimental, observational studies and trials (interventional studies).
>Defining a Dive Study
- Experimental studies involve divers or human cells that are exposed to known and controlled factors. These studies help researchers gain insight to the human physiological responses to various stimuli that mimic natural diving conditions; they require great precision and advanced setups. One example of an experimental study is the Flying After Diving Calibration Study. This study is designed to evaluate the effect of altitude exposure following diving in a hyperbaric chamber based on circulating bubble production and/or development of decompression sickness.
- Observational studies involve collecting data through observations, interviews and surveys. An example of an observational study is Project Dive Exploration, which entails collecting and analyzing dive profile data from real dives as well as diver behavioral and health trends. The Patent Foramen Ovale (PFO) Study is another observational study involving data collection on incidences of DCS and comparing divers with a PFO who undergo PFO closures to those who continue diving without closure.
- Trials or interventional studies are essentially a combination of experimental studies and observational studies. As the name suggests, an intervention (a measure that is expected to improve diving or reduce dive related injuries) is introduced. One group of divers would apply the intervention while the other group would continue diving without it. Then, the health and well-being of these two groups would be evaluated and compared.
>The intent of scuba diving research is to gain more knowledge on the effects of diving on divers' health and safety. In any research involving humans, the ultimate goal is to pursue knowledge while ensuring the basic rights of the participants are protected. It is also essential to consider the feasibility of the study. To make sure these goals are met, the United States Office of Human Research Protection (OHRP) requires every institution involved in research in the United States to be affiliated with an Institutional Review Board (IRB). Each IRB adopts the regulations put forth by the OHRP according to the needs of their primary field of research. For example, DAN has an IRB, so the DAN IRB's regulations are tailored to scuba diving. IRBs require all researchers to undergo specialized ethics training before being permitted to conduct or be a part of any research. An IRB ensures the following in each research study:
>IRB: Ensuring Research Participant Safety
- Risks to the involved participants are minimized.
- The benefits of the research to the population exceed the risks to the involved participants.
- The selection of the study participants is equitable.
- If human subjects are involved in the study, their informed consent is taken
- Data is monitored and secured.
- Proper confidentiality and safety of the participants is maintained.
- Educationally disadvantaged and vulnerable populations like children, pregnant women, prisoners, disabled, etc., are protected.
>Observational studies and trials/interventional studies are primarily epidemiological studies, which for our purposes takes a look at health events and patterns in divers. These studies collect real-life data from divers; this process can be retrospective or prospective data. There are multiple ways to accomplish this form of data collection. For example, to collect retrospective data researchers can analyze health insurance claims data. Such studies generally provide the incidence of any injury, disease or a medical condition. For instance, DAN researchers used this data to calculate the death rates attributable to diving accidents among insured DAN members from 2000-2006; the average rate was 16.4 per 100,000. Current examples of prospective data collection studies that DAN is conducting include Project Dive Exploration and the PFO study.
>Epidemiological Studies: Observing and Analyzing Trends
>Another way of collecting data is through surveys, which effectively gather both retrospective and prospective data. At DAN, most of the data collected through surveys is participant-reported data. Survey creation and validation is a complex process that involves many steps to ensure the survey complements the goals and objectives of the study.
Case Study: Survey Creation Process
We recently finished working on a survey at DAN, titled the DAN Membership Health Survey. The purpose of this study is to evaluate the current health status, use of preventive medical services, diving practices and prevalence of reported and unreported injuries in insured DAN members in the past year.
The questionnaire was primarily created by conducting a literature review of previous diving studies, which allowed us to determine how different study questions were previously answered. Based on these reviews and the goals of our study, a first draft of the questionnaire was prepared. The survey then went through a thorough validation process. The initial draft was reviewed by the DAN training staff to ensure that we included commonly used recreational and professional diving terminology. The corrected questionnaire was further reviewed by the DAN medical information team, dive medicine physicians and researchers. The final revised questionnaire was then sent to 15 scuba divers for pretesting to determine the usability of the survey. The next step will be to convert the questionnaire into an online survey, and collect the data through our protected servers. The collected digital data will be readily available for statistical analysis.
The participants for this study will be a randomly selected sample of 30,000 subjects from about 150,000 DAN members, irrespective of their age and sex. The preselected members will be sent a link to an online survey via email. Prior to answering any questions, each participant will review and sign a digital informed consent form.
This study will help us to establish the prevalence of obesity, diabetes, asthma, heart diseases, risk factors for cardiovascular diseases, common diving-related injuries and use of preventive medical services among insured DAN scuba diving population, thus giving clues to reduce and mitigate such risks. The knowledge gained from this study may be used in future interventional studies that will advance the scuba diving safety among divers.>Depending on the type of the epidemiological study, the number of participants, the data collection method (retrospective or prospective) and financial considerations, research studies in scuba diving can take from just a few months up to decades to complete. Each study strives to provide greater insight into dive safety. Above all, it's the participation of scuba divers that drives the continuance and credibility of our research.
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