A retrospective review of the utility of chest X-rays in diving and submarine medical examinations.

Introduction: Performance of routine Chest X-rays (CXRs) in asymptomatic individuals to assess hyperbaric exposure risk is controversial. The radiation risk may overshadow the low yield in many settings. However, the yield may be higher in certain settings, such as tuberculosis-endemic countries. We evaluated the utility of routine CXR in diving and submarine medical examinations in South Africa. Methods: Records of 2,777 CXRs during 3,568 fitness examinations of 894 divers and submariners spanning 31 years were reviewed to determine the incidence of CXR abnormality. Associated factors were evaluated using odds ratios and a binomial logistic regression model, with a Kaplan-Meier plot to describe the duration of service until first abnormal CXR. Results: An abnormal CXR was reported in 1.1% per person year of service, yielding a cumulative incidence of 6.5% (58/894) of the study participants. Only four individuals had a clinical indication for the CXR in their medical history. A range of potential pathologies were seen, of which 15.5% were declared disqualifying and the rest (84.5%) were treated, or further investigation showed that the person could be declared fit. Conclusions: In South Africa, a routine CXR has a role to play in detecting abnormalities that are incompatible with pressure exposures. The highest number of abnormalities were found during the initial examinations and in individuals with long service records. Only four individuals had a clinical indication for their CXR during the 31-year span of our study. Similar studies should be performed to make recommendations in other countries and settings.

Dispositional resilience predicts psychological adaptation of seafarers during and after maritime operations.

BACKGROUND: Seafarers, whether on cargo, fishery, or naval ships, may be exposed to unique and unusual psychological demands related to the often isolated, confined, and extreme environments associated with ocean-going vessels. This necessitates optimal psychological adaptation to maintain individual well-being during the mission and afterwards. This study set out to explore whether psychometric measures could predict psychological adaptation of seafarers, specifically navy sailors, during and after maritime operations. It used emotional regulation as marker of adaptation, and examined the role of psychometric measures of dispositional resilience and emotional regulation to predict psychological adaptation at subsequent time-points. MATERIALS AND METHODS: A total of 168 sailors completed the Brief Sailor Resiliency Scale, Dispositional Resilience Scale 15, and Mental Toughness Questionnaire 18 prior to departing for sea, as well as the Brunel Mood Scale at 5 time points over a 12-month operational cycle. RESULTS: Higher resilience scores were consistently associated with more adaptive emotional regulation. Multiple linear regressions indicated that the Brief Sailor Resiliency Scale predicted emotional regulation over the shorter term, while the Mental Toughness Questionnaire 18 predicted emotional regulation over the longer term. Further, mid-mission emotional regulation also predicted emotional regulation at the end of deployments. CONCLUSIONS: The findings support several practical applications. Firstly, formal organizational initiatives to promote resilience could be useful to enhance adaptation during and after missions. Secondly, measuring seafarers' dispositional resilience could allow the streaming of vulnerable individuals towards appropriate mental health support services. Thirdly, past indicators of adaptation could be useful to enhance decision- making regarding subsequent utilisation. This may be applicable to seafarers in both naval services and commercial shipping, and to personnel in remote weather stations or other isolated and inaccessible research facilities.

A Concise Occupational Mental Health Screening Tool for South African Workplaces.

Mental health in the workplace is becoming of ever greater importance. General occupational health surveillance programmes are already in widespread use, with established referral systems for treatment and rehabilitation, and the same mechanisms could be expanded to include mental health screening and intervention. This study aimed to develop a concise composite mental health screening tool, based on analysis of existing data, for application in routine occupational health surveillance in South Africa. Data from workplace occupational health surveillance programs from 2,303 participants were analysed. Participants completed a number of questions/scaled items collated into a survey format, and partook in an interview with a psychologist. The data was analysed using frequency of positive self-reports, Chi square to calculate associations with outcomes, Receiver Operator Characteristic curve analysis to explore predictive ability, and binomial logistic regression to calculate the relative contribution of markers to outcomes. An exploratory factor analysis was further conducted on identified items. A general workplace model with 14 markers (and a maritime workplace model with 17 markers) were identified. The factor analysis suggested their organisation into five domains (similar for both models), namely neurocognitive health, common mental disorders, history of adaptation in occupational specific contexts, family-work interface, and stress overload. The study's data-driven approach proposed a concise composite screener with less than 50 items, comprising five domains. This tool appears useful in identifying employees at risk for workplace injuries or poor mental health outcomes, and could be applied to related workplace settings in South Africa.

Associations Between Adverse Underwater Events and ADHD Diagnosis Among Military Divers.

Objective: Adult ADHD (A-ADHD) has been associated with an increased risk of accidents and workplace injuries. ADHD within professional diving may have major potential occupational health and safety implications, as accidents underwater may have severe consequences. The study investigated any association of increased risk for adverse underwater incidents with an ADHD diagnosis. Method: This analysis used retrospective records from 156 navy divers and computed an odds ratio using cases of ADHD and cases of underwater accidents. Results: Although the odds ratio was increased, it failed to reach significance. Conclusion: We do not yet have statistical evidence suggesting that the risk for adverse underwater events is significantly increased among the ADHD group in this sample of navy divers. Sufficiently powered studies are required to further address the potential risk of A-ADHD in working divers.

Common mental health conditions among navy divers: A brief report.

INTRODUCTION: A recent article reported on common mental health conditions among recreational scuba divers, and observed that the prevalence mirrored national population figures. This raised the question of the extent to which this might also be the case among professional divers. No data on commercial divers could be located; this paper presents the situation among navy divers. METHODS: Mental health survey data from 132 South African Navy divers were reviewed to describe the 12-month prevalence of common mood, anxiety, and alcohol misuse disorders. RESULTS: Prevalence of common mood and anxiety conditions appeared to reflect local general population estimates, and the occurrence of alcohol misuse was higher than local population figures, although the usefulness of the population data could be challenged. CONCLUSIONS: It appeared that common mental health conditions in both sport and navy divers may generally conform to their respective local general population estimates. If this were to be the case in the broader professional diving environment as well, the inclusion of some form of formal mental health screening during commercial diving medical examinations may be beneficial.

Adult attention-deficit/hyperactivity disorder prevalence among commercial divers in South Africa.

INTRODUCTION: Adult attention-deficit/hyperactivity disorder (ADHD) is associated with increased chance of workplace accidents, psychiatric comorbidities, other risky behaviours and sophisticated psychopharmacological treatment. These factors all contribute to a potentially complex risk profile within the commercial diving context. In order to make informed decisions regarding ADHD and commercial diving, further description of this condition among commercial divers is required. This paper reports on a study that aimed to determine the prevalence of adult ADHD among commercial divers. METHODS: The study used a self-reporting survey-type questionnaire to determine likely diagnosis, based on Diagnostic and Statistical Manual of Mental Disorders, 5th ed. criteria, in a group of 245 commercial divers in South Africa. RESULTS: Fourteen cases (5.7% of the sample) met criteria for ADHD. The majority of the cases presented with combined type, and reflected mild forms of ADHD. Adult ADHD did not appear to occur in significantly different proportions across the biographical variables of age, education or diving qualification. CONLCUSION: Based on this small survey, adult ADHD may be over-represented in commercial diving in South Africa, compared to general workplace populations. However, ADHD may not necessarily be a contra-indication to commercial diving.

Diving, cannabis use, and techniques of neutralisation: exploring how divers rationalise cannabis use.

BACKGROUND: Diving medicine literature often regards the use of cannabis as a potential contra-indicator for fitness to dive. With that said, there has been no empirical research done with cannabis-using divers to examine how they subjectively understand and construct the risks that their cannabis use may have on their diving. This study explored how cannabis-using divers rationalise the pejorative associations of cannabis use through rhetorical techniques of neutralisation (TON) that function to deny the risks that cannabis use may have on their diving. MATERIALS AND METHODS: Ten medically-fit professional divers from South Africa were individually intervie- wed. The interviews focussed on each diver's reported recreational use of cannabis. The interviews were transcribed and analysed through a framework for TON originally formulated by Sykes and Matza (1957). RESULTS: Analysis revealed six primary TON employed to refute the pejorative associations of cannabis use on dive work, namely: 1. Denial of responsibility: which denies a diver's direct culpability for their cannabis use; 2. Denial of injury: which asserts that no (serious) harm results from a diver's cannabis use; 3. Denial of victim: which repudiates the potentially deleterious effects that cannabis use may have on a diver; 4. Condemnation of condemners: which minimises cannabis use in relation to other divers' unsafe diving practices; 5. Appeal to loyalties: which situates cannabis use within interpersonal networks to whom a diver has a "higher" allegiance; 6. Denial of penalty: which justifies cannabis use by virtue of a perceived lack of punitive action by a Diving Medical Examiner. CONCLUSIONS: The findings of this research highlight the TON which potentially inform a diver's cannabis use, particularly in relation to their diving. Identifying such TON carry important implications for the ways in which fitness to dive is assessed.

Personality profiles of divers: integrating results across studies.

BACKGROUND: There are numerous reports on diver personality, spanning across five decades, across national boundaries, and using a range of measures to describe diver profiles. However, the range of reports poses challenges to interpreting new studies, particularly when having to compare findings across generations, measurements, and national/cultural contexts. This paper aimed to review and integrate diver personality descriptions, drawing on the available studies that reported trait theory based data for naval and sport divers. MATERIALS AND METHODS: Available studies on diver personality - associated with trait theory - were tabulated and the specific traits associated with divers described. Their findings were then integrated into a synthesised description of personality traits. RESULTS: The results suggest remarkably stable military diver profiles across generations, measures, and navies, with some unique differences observed due to national-cultural variables. It was of particular interest that different measures of personality appeared to present related constructions of diver profiles. Navy divers share, among others, a propensity for adventurousness, a strong sense of self-agency, and low trait anxiety. Unsurprisingly, personality profiling could not be generalised across military-civilian diving contexts, and the same clear profile differentiation of navy divers was not visible among sport divers. CONCLUSIONS: Contemporary local data - in the context of military diving - could productively be compared to the body of existing reports, at least where similar theoretical models are used.

Personality and behavioural outcomes in diving: current status and recommendations for future research.

This paper provides a brief overview of the shift from studies describing the personality profiles of divers to studies exploring associations between personality variables and diving performance in terms of behavioural outcomes. The personality associations that were investigated include performance during training, panic proneness, diving injuries, susceptibility to inert gas narcosis, and the behaviour of tourist divers. The paper concludes with a number of suggested directions for further research on personality and diving that may provide tangible benefits in terms of both enhanced safety and improved performance underwater.

Psychological considerations in submarine escape training: brief overview and future directions.

The inability of a submarine to surface must rate as one of greatest risks to sailors in peacetime. To prepare for such emergencies, many navies provide training to master the procedures required to escape successfully from disabled submarines. This paper provides a brief overview of some of the psychological principles in simulated submarine escape training. It further discusses applicable psychological constructs such as positive outcome expectancies, the role of anxiety, and other personal factors mediating outcomes of such training. It concludes with recommendations for future research aimed at enhancing the safety and impact of submarine escape training. These include enhanced detection of psychological risk factors such as anxiety, as well as investigating the relative contribution of personality variables to in-training safety and positive outcome expectancies. These recommendations do not only apply to submarine escape training, but may also be applicable to high fidelity safety training in other off-shore survival contexts, such as helicopter underwater escape training, freefall lifeboat training and smoke diving.

Diving under the influence: issues in researching personality and inert gas narcosis.

BACKGROUND: This paper considers the relationship between measures of personality and mood states, and susceptibility to inert gas narcosis. It briefly reviews the topics of inert gas narcosis affecting personality, and personality affecting the susceptibility to inert gas narcosis. There appears to be is a theoretical argument for a possible relationship between measures of personality, mood states, and susceptibility to narcosis. Practically, such a relationship may speak to issues in selection, training and preparation, risk assessments, and even accident investigation in the diving and/or hyperbaric environment. MATERIALS AND METHODS: Twenty one divers completed measures of personality and mood states, and were then compressed to 709 kPa (equivalent to 60 msw) in a dry compression chamber, where they completed a task measuring speed of information processing, and a scale measuring subjective narcosis. RESULTS AND CONCLUSIONS: The main finding was the absence of any significant correlations between measures of personality traits and mood, and susceptibility to inert gas narcosis. Although the study found no evidence of any major relationship, it is presented as a case study to highlight some of the issues and pitfalls involved in such research. The lessons learned - including the careful defining and describing of concepts, and choosing of samples and measurements - are used to discuss some of the methodological and conceptual issues and future directions for researchers to consider.

Effect of a Faith-Based Education Program on Self-Assessed Physical, Mental and Spiritual (Religious) Health Parameters.

The aim of the study was to determine the effect of attending a faith-based education program (FBEP) on self-assessed physical, mental and spiritual health parameters. The study was designed as a prospective, observational, cohort study of individuals attending a 5-day FBEP. Out of 2650 sequential online registrants, those previously unexposed to the FBEP received automated invitations to complete 5 sequential Self-Assessment Questionnaire's (SAQ's) containing: (1) Duke University Religion Index (DUREL); (2) Negative Religious Coping (N-RCOPE); (3) Perceived Stress Scale (PSS); (4) Center for Epidemiology and Statistics-Depression Scale (CES-D); (5) Brief Illness Perception Questionnaire (BIPQ); and the (6) State Trait Anxiety Inventory (STAI). Pre-attendance SAQ (S1) was repeated immediately post-FBEP (S2), at 30 days (S3), 90 days (S4) and after 1 year (S5). Of 655 invited, 274 (42 %) succeeded, 242 (37 %) failed and 139 (21 %) declined to complete S1. Of the 274, 37 (14 %) were excluded at on-site interview; 26 (9 %) never attended the FBEP (i.e., controls: 5♂; 21♀; 27-76 years); and 211 (77 %) participated (i.e., cases: 105♂; 106♀; 18-84 years) and were analyzed over time: 211 (S1); 192 (S2); 99 (S3); 52 (S4); 51 (S5). IRB approval was via the Human Research Ethics Committee of Stellenbosch University. DUREL showed significant, sustained changes in Intrinsic Religiosity. N-RCOPE showed significant, lasting improvement. In others, median values dropped significantly immediately after the FBEP (S1:S2) for STAI-State p < 0.0001; PSS p < 0.0001; BIPQ p < 0.0001; and CES-D p < 0.0001; and at 1 month (S1:S3) for STAI-Trait p < 0.001; all changes were sustained (S3 through S5). This FBEP produced statistically and clinically significant changes; these lasted in those followed up >1 year.

The use of Spielberger's State-Trait Personality Inventory (trait anxiety subscale) with naval subaquatic specialists.

OBJECTIVES: Panic behavior poses a particular threat to the health and safety of subaquatic occupational specialists. Trait anxiety has previously been identified as a marker of panic behavior under water, and Spielberger's State-Trait Personality Inventory (trait anxiety subscale) has been previously used to measure trait anxiety among subaquatic specialists. Using archived data, the trait anxiety scores of subaquatic specialists were analyzed to meet 3 objectives: 1stly - to develop a trait anxiety profile of subaquatic specialists; 2ndly - to investigate the predictive value of trait anxiety measures upon entering an occupational field; and 3rdly - to establish the reliability of these scores over time. MATERIAL AND METHODS: Archival trait-anxiety data from 322 subjects were analyzed statistically. RESULTS: Analysis of the available scores revealed a highly homogenous as well as a very low trait anxiety profile for the investigated occupational group. Additionally, low trait anxiety was somewhat associated with success during specialist training: fewer candidates with high trait anxiety scores completed their qualification. Moreover, measurement of trait anxiety was stable over time, which suggests that when scores for this occupational group are screened, deviations from previous scores could signify a potential need for referral to an intervention from health professionals. CONCLUSIONS: Using the trait anxiety subscale as part of occupational health surveillance of subaquatic specialists could support prevention of accidents by identifying high-risk candidates during their annual health assessments, and referral for timeous intervention.

Complex tactile performance in low visibility: the effect of nitrogen narcosis.

BACKGROUND: In a task-environment where visibility has deteriorated, individuals rely heavily on tactile performance (perception and manipulation) to complete complex tasks. When this happens under hyperbaric conditions, factors like nitrogen narcosis could influence a person's ability to successfully complete such tasks. OBJECTIVE: To examine the effect of nitrogen narcosis on a complex neuropsychological task measuring tactile performance at a pressure of 608 kPa (6 atm abs), in the absence of visual access to the task. METHODS: In a prospective cross-over study, 139 commercial divers were tested in a dry chamber at 101.3 kPa and 608 kPa. They completed the Tupperware Neuropsychological Task (TNT) of tactile performance without visual access to the task, and completed questionnaires to provide psychological and biographical data, which included trait anxiety and transient mood states, as well as formal qualifications and technical proficiency. RESULTS: A significant decrement (9.5%, P < 0.001) in performance on the TNT at depth was found, irrespective of the sequence of testing. Generally, neither the psychological nor biographical variables showed any significant effect on tactile performance. Tactile performance on the surface was a good indicator of performance at depth. CONCLUSION: These findings have practical implications for professional diving where conditions of low visibility during deeper diving occur. Recommendations are made towards managing potential impairments in tactile performance, such as pre-dive practical learning ('rehearsal') as an aid to successful completion of tasks.

Subjective Narcosis Assessment Scale: measuring the subjective experience of nitrogen narcosis.

BACKGROUND: The interaction of subjective experiences and objective measures of neuropsychological performance during hyperbaric exposure has received less attention in the literature, in part due to the shortage of available and appropriately standardized measures. OBJECTIVE: This study aimed to describe the psychometric properties of a modified version of the Subjective High Assessment Scale when used in the hyperbaric context, by exploring internal reliability, factor structure, associations with psychological variables and simple cognitive delayed recall, and the effect of task focus on the recall of subjective experience. METHOD: Seventy qualified divers completed dry hyperbaric chamber dives to 607.95 kPa, and completed ratings of their subjective experiences. Some also completed a delayed recall task and psychological measures prior to their dives. RESULTS: The scale displayed good internal consistency, with four meaningful factors emerging. It showed some significant but small associations with trait anxiety and transient mood states, and a small to moderate correlation with recall performance. There was no significant effect of task focus on self-report of subjective experiences. CONCLUSION: The modified scale, renamed the Subjective Narcosis Assessment Scale here, has useful psychometric properties, and promising potential for future use.

Nitrogen narcosis and tactile shape memory in low visibility.

OBJECTIVE: Commercial diving often occurs in low visibility, where divers are reliant on their tactile senses. This study examined the effect of nitrogen narcosis on tactile memory for shapes as well as the influence of psychological and biographical factors on this relationship. METHOD: This crossover study tested 139 commercial divers in a dry hyperbaric chamber at 101.325 and 607.95 kPa (1 and 6 atmospheres absolute/atm abs). Divers memorized shapes while blindfolded, using their tactile senses only. Delayed recall was measured at the surface after each dive. Psychological and biographical data were also collected. RESULTS: A significant effect of hyperbaric pressure on tactile memory was demonstrated, and a further effect of sequence of testing found. Thus, divers' delayed shape recall deteriorated by 8% after learning material at depth, compared to learning on the surface. There were also significant but small effects of psychological and biographical markers on tactile memory performance, with lower trait anxiety associated with better recall, and lower education associated with poorer recall. CONCLUSION: The findings emphasize the importance of utilizing other forms of recording of events or objects at depth, particularly in conditions of low visibility during deeper diving, to aid memory encoding and subsequent recall at the surface.

Clinical utility of the brunel mood scale in screening for post-traumatic stress risk in a military population.

Measures of mood states and post-traumatic stress (PTS) symptoms are commonplace in many studies. However, the conventional application of these measures conjointly raises questions whether they actually correlate, and whether mood states have a meaningful role in predicting PTS symptoms. This study aimed to assess the degree to which the Brunel Mood Scale (BRUMS) and the Impact of Event Scale-Revised (IES-R) would be useful in detecting adverse psychological experiences (e.g., PTS). A sample of South African Navy sailors (N = 103) completed the BRUMS during demobilization after a traumatic deployment, and 6 weeks later completed a repeat BRUMS and the IES-R. Significant correlations were found between some BRUMS and IES-R subscales, but the lack of other subscale correlations indicates that the two measures probably tap different expressions of psychological distress following exposure to adverse events. Greater mood distress correlated with more severe PTS. A BRUMS total mood distress score cutoff of ≥24 gave a sensitivity of 100% and specificity of 79% for severe PTS 6 weeks later. Using a BRUMS score of ≥24 at demobilization to assess for possible elevated PTS response later could be useful in the screening of large groups of people.

Influence of item sequence on transient mood assessment.

The present study compared self-reported transient mood assessment using two different presentations of the sequence of mood scale items. A sample of 300 adults completed the standard Brunel Mood Scale and, after a distraction task, completed an experimental version composed of items grouped along the original subscales. A further 292 adults completed the scales in reverse order. After analysis, no significant differences in response patterns were observed. Results suggested that items sequenced non-randomly and according to mood subscales do not affect the accuracy of transient mood assessment. This suggests that for administration to large groups, the experimental version maintains the psychometric validity of the standard version while at the same time being more time-effective to score.

Mental health measures in predicting outcomes for the selection and training of navy divers.

INTRODUCTION: Two models have previously been enlisted to predict success in training using psychological markers. Both the Mental Health Model and Trait Anxiety Model have shown some success in predicting behaviours associated with arousal among student divers. This study investigated the potential of these two models to predict outcome in naval diving selection and training. METHODS: Navy diving candidates (n = 137) completed the Brunel Mood Scale and the State-Trait Personality Inventory (trait-anxiety scale) prior to selection. The mean scores of the candidates accepted for training were compared to those who were not accepted. The mean scores of the candidates who passed training were then compared to those who failed. A number of trainees withdrew from training due to injury, and their scores were also compared to those who completed the training. RESULTS: Candidates who were not accepted were more depressed, fatigued and confused than those who were accepted for training, and reported higher trait anxiety. There were no significant differences between the candidates who passed training and those who did not. However, injured trainees were tenser, more fatigued and reported higher trait anxiety than the rest. Age, gender, home language, geographical region of origin and race had no significant interaction with outcome results. CONCLUSIONS: While the models could partially discriminate between the mean scores of different outcome groups, none of them contributed meaningfully to predicting individual outcome in diving training. Both models may have potential in identifying proneness to injury, and this requires further study.

Assessing tactile perception: effects of different visual barriers on performance.

Blindfolding candidates when testing their tactile performance may increase their anxiety. This study examined whether different visual barriers would influence tactile performance on timed tasks. It was hypothesised that candidates using a blindfold would be more anxious, but that they would benefit by the potentially positive effects of arousal on performance and not differ from candidates using a screen to limit visual access to task material. 200 participants (ages 19 to 30 years), randomly assigned to the two conditions, completed a tactile perception task, as well as an anxiety scale. In contrast to the expected outcome, the screen sample took significantly longer to complete the task. This was hypothesised to be the result of increased distraction given competing cross-modal attentional demands and the consequent visual and tactile attention switching. Practitioners may need to consider the influences of visual interference when assessing tactile performance.