Mapping the knowledge base for maritime health: 4 safety and performance at sea

There is very little recent investigative work on the contribution of health related impairment and disability to either accident risks or to reduced performance at sea, the only exception being studies on fatigue and parallel data on sleep related incidents. Incidents where health related impairment, other than fatigue, has contributed are very rarely found in reports of maritime accident investigations. This may either indicate the irrelevance of these forms of impairment to accidents or alternatively point to the effectiveness of existing control measures. The main approach to risk reduction is by the application of fitness criteria to seafarers during medical examinations. Where there is a knowledge base it is either, as in the case of vision, a very old one that relates to patterns of visual task that differ markedly from those in modern shipping or, as with hearing, is based on untested assumptions about the levels of impairment that will prevent effective communications at sea. There are practical limitations to the assessment of cognitive functions as these encompass such a wide range of impairments from those associated with fatigue, medication, or substance abuse to those relating to age or to the risks of sudden incapacitation from a pre-existing illness. Physical capability can be assessed but only in limited ways in the course of a medical examination. In the absence of clear evidence of accident risks associated with health-related impairments or disabilities it is unlikely that there will be pressure to update criteria that appear to be providing satisfactory protection. As capability is related to the tasks performed, investigations need to integrate information on ergonomic and organizational aspects with that on health and impairment. Criteria that may select seafarers with health- -related impairment need to be reviewed wherever the task demands in modern shipping have changed, in order to relax or modify them where indicated in order to reduce unjustifiable discrimination

Mapping the knowledge base for maritime health: 2. a framework for analysis

The knowledge base for maritime health has a number of constant features that have become apparent over the last 150 years. These can be used to structure an analysis of the current state of knowledge and to identify where there is sound evidence about the nature and scale of risks and about the effectiveness of intervention to reduce harm. It can also show where there are deficiencies in knowledge and point to the ways in which these could be remedied. Past events, as discussed in the first article, also indicate the dynamics of the political, economic and human interactions that are central to improving knowledge and to its application to improve the health of seafarers. The sources of useful knowledge about seafarer’s health range from single case reports of an unusual disease to long-term studies of common chronic disease incidence. The most accessible events to record are clinically apparent illness, injury, or cause of death, but active investigative studies may look at risks in the environment, personal risk factors, or pre-clinical phases of disease. Comparisons between subsets of a population are needed to look rigorously at health risks or at the effectiveness of intervention. This is best done if information on the at risk population can be used as the basis for deriving the incidence or prevalence of illness and if the populations compared are as similar as possible in every way, except that being studied. Sometimes large studies in onshore populations can provide information that it is not feasible to collect on seafarers. Information on seafarers’ health can be collected in several settings: at sea, on arrival in port, during leave periods, or after retirement. For acute illness and for injury a single setting can provide the basis for estimating risks, but for chronic conditions cases arising in several settings have to be included and the at risk population calculated to enable the incidence to be studied. Knowledge about the health of seafarers can be used to improve prevention both by attention to the conditions of living and working at sea and by selection of seafarers who are considered ‘fit’ for work. It is also important for defining the needs for emergency care at sea and in port. The overall patterns of illness and injury in seafarers and how these compare with other workers are important inputs to regulatory decisions on the measures to be taken to reduce harm from illness and injury. Markers of improved seafarer health can confirm the effectiveness of measures taken with this goal in mind. Reducing the contribution of health-related impairment to accidents and other risks at sea requires knowledge of the effects of such impairments on performance and safety in the routine and emergency tasks of a seafarer. This information can then be used to determine whether someone with an impairment can safely work at sea

The need for international seafarer medical fitness standards

The text of this paper is based on a presentation at the First International Congress of Maritime, Tropical, and Hyperbaric Medicine, 4th July 2009, Gdynia, Poland. The assessment of fitness to work at sea is an important aspect of maritime risk management. The risks in the industry, the approaches used for assessment, and the evidence on which they are based have changed over time. The transition from an industry in which the nationality of seafarers and the ships on which they worked were the same to one in which ownership and crewing have become global means that, as is true for most other aspects of maritime risk management, compatible international criteria for decisions regarding fitness to work are required. Many parties, including flag states, employers and their insurers, and seafarers and their trade unions, are involved in agreeing international medical fitness criteria. While all have a common interest in improved health and safety at sea, each has their own more detailed agenda of sectional interests. The scope for development of agreed standards and the role of the parties involved is reviewed, and the current arrangements for taking this process forward are discussed. Contributions from maritime health professionals and other medical and scientific experts are essential to the development of rational and valid criteria, but the decisions on the level of authority to be given to these and the means adopted for ensuring compliance with them are essentially political issues where the voice of those with subject knowledge is only one among many in the processes for adoption and implementation of any new arrangements

Mapping the knowledge base for maritime health: 1 historical perspective

There have been major developments in the understanding of disease and its treatment in the last 150 years. The development of the knowledge base on patterns of disease and injury in seafarers and on the effectiveness of intervention to prevent and treat them indicates the sorts of information that were collected and the settings in which it was possible to collect it. They also show how it has been used, as well as the reactions of those in the maritime sector to the collection and analysis of health information and to its use as a means of reducing harm

Mapping the knowledge base for maritime health: 3 illness and injury in seafarers

Recent studies of illness and injury in seafarers and of disease risk factors have been mapped. There is a good knowledge base on some aspects of health, especially on causes of death. By contrast there are very few studies on aspects of current importance, such as illness at sea, the scope for its prevention, and its treatment and outcome. Results are presented in terms of the settings in which the investigations were conducted: medical fitness examinations at recruitment and periodically, illness and injury at sea, telemedical advice, evacuation and urgent port referrals, repatriations, illness at other times in serving seafarers, health related cessation of work, and illness after cessation of work. Mortality studies were mapped in a similar way, as were population-based surveys of health and of risk factors. The scope for valid extrapolation of the results from studies in other populations to seafarers is discussed. A more immediate problem of extrapolation relates to the current knowledge base, which is largely derived from own nationality seafarers of the traditional developed world maritime nations. It is uncertain whether this can be validly extrapolated to seafarers from the major crewing countries, who come from populations with very different patterns of illness. Existing studies mirror the priorities of those who commissioned them, in that many of the most valid ones relate to the overall lifetime risks of seafaring in developed countries. These enable comparisons to be made with other occupational groups. The major concerns of many interest groups in the maritime sector about health are now focused on the risks within a single contract period and how these can most efficiently be minimized. Studies on this are limited in scope, are of uncertain validity, and are often used for operational purposes rather than entering the scientific literature. Gaps in knowledge about health risks over a relatively short timescale in seafarers from the major crewing countries have been identified, and the uncertainties about extrapolating from studies in traditional maritime nations to the majority of the world’s seafarers means that a major redirection of effort is needed if maritime health practice is to have a sound knowledge base on illness and injury risks in the future