Catherine S. Gotschall
|In keeping with the conference theme “Towards Consensus,” attendees participated in two semi-structured small group discussions. In these sessions the issues raised by the presenters were considered and efforts made to work towards consensus concerning the issues, where possible. The first session focused on issues relating to health status, quality of life measures, and rehabilitation measures. The second session focused on issues relating to economic measures of injury burden. This section of the Proceedings is a composite summary of the discussions.|
An important issue in any measurement of injury burden is the injured person’s pre-injury state. The discussion centered around two possibilities: establishment of population references against which to compare patients, or asking injured persons about their pre-injury state.
Although population norms would make it easy for an investigator to estimate average pre-injury status, little is known about norms relative to risk levels, which are considered to be an important parameter in establishing the most appropriate population upon which to base an estimated pre-injury state. Some level of consensus was reached that asking injured persons about their pre-injury health status was desirable, but certain limitations needed to be taken into account. These limitations include the need to measure pre-injury state very soon after injury, and that not all instruments were amenable to such an application.
Other considerations discussed include the fact that health changes are often non-linear; many health status instruments are cross-sectional; it is difficult to assess the significance of pain when retrospectively asking about it in a post-injury measurement; it is important to take special care with child population norms; and the effect of depression on the person’s perception of health status must also be included.
There was general agreement over which domains to include in any measure of health status post injury, with the following considered critical:• Symptoms after injury • Health perceptions • Function (physical, cognitive, psychosocial) • Social role (emotional, age sensitive, cultural norms, employment, transportation for movement within community, leisure activities, home management and play) • Subjective well-being; anxiety levels • Pain/discomfort • Vitality (sleep impairment, depression and sexual function) • Productivity – not simply returning to work, but to what level of work
There was also general consensus that at the current stage of development there is no single instrument that can be used to measure overall health status in all cases. Rather, researchers need to choose among the available instruments and supplement them with additional questions, some to make up for short-falls in the coverage of the instrument and others to determine factors that may be unique to a specific injury. The choice of instrument(s) depend(s) on a number of factors, including the goal of the research; whether the research is population-based or clinically-based; the severity of the injury and the timing of the measurement. Many of the attendees expressed the opinion that the Short Form Health Survey (SF-36) was a good instrument to use as a base, but some additional questions must be added in order to capture cognitive function, an important aspect of overall health status missing from the SF-36.
When discussing the issue of modifying an already validated instrument it was agreed that it would be best to add questions at the end, so there would be no need to re-validate anything except the new questions, as even seemingly small changes in question order can change responses. It was also agreed that it is important to report the specific “adaptations” that have been made to the original scale when publishing findings.
Another issue discussed was timing of measurement. At what point after an injury should the measurement occur, should it involve multiple pre-discharge assessments, and will this factor vary depending on the type of injury? The consensus view was that ideally it would be useful for there to be measurement at different points in time; not just once, but that the answer to this question would depend on the body region where the injury occurs.
Biases were also discussed. There is a known bias for self-reporting, but other biases are apparent when proxies are used. Parents, for example, often have a different perception of their child’s injury than the child has, and these perceptions may differ from one parent to the other. More research to assess how individuals describe themselves would be desirable.
The role of depression in injury outcome was considered. There may have been depression pre-event; therefore it is often not possible to know how much of a given patient’s depression falls on which side of the event. This is a particular problem in intentional injuries.
The attendees agreed that there are several factors to consider when developing the next generation of instruments. They include: incorporating screening questions that allow for redirecting based on the initial responses; modifications for specific injuries; accounting for the needs of particular users, since clinicians’ requirements may vary from researchers’; the severity of the injury, time available, the desired level of detail; and the application to injury-specific studies or global studies. There was general agreement that the ideal tool would have a range of administration times from 2 minutes for a “healthy” person to no more than 40 minutes for persons with a serious injury. Other factors discussed include the need to maintain sensitivity to changes in functioning over time, across different conditions, and sensitivity to differences in basic health status as people age.
The group also discussed another important factor to consider in any instrument development, the issue of cultural norms and levels of resources available. The participants were very “Western” oriented, but even in the United States, there is great diversity, with many populations ‘challenged’ and varying from the norm. If it is intended for an instrument to be widely applied it will be necessary to consider not only cultural and economic diversity but also agrarian vs. industrialized populations. Even if it were appropriate to translate a health status scale into other languages, it may not be appropriate to use the same preference weights.
The participants pointed out that there is no professional body with external credibility to develop a consensus document for a quantitative/qualitative process of evaluation for health status measures. It was recommended that an international working group be established to carry out this task and present a report at the next international meeting.
The discussions on measuring the economic costs resulting from injury focused on the characteristics/categories of the costs that should be reported in order to facilitate comparisons and educate readers. These discussions were not an exercise in judging the legitimacy of some categories vs. others, but an effort to standardize the reporting of costs. It is essential to consider that many cost issues will be measured differently in many regions/countries due to variations in laws, cultures, and health care systems. The burden of costs may fall on each society in disparate ways. In any case, the following cost categories were considered to be essential.
The participants identified numerous potential barriers to obtaining quality cost data, including philosophical, ethical and technical issues as well as conflicting agendas. Ideally peer review could minimize some of these difficulties. Other relevant data quality barrier issues are privacy, lack of resources, and standardization of measures such as discount rates. There may also be political barriers. Politicians may not be motivated to address what are considered to be very esoteric and possibly politically volatile issues.
Evaluating costs of injury can be done from a number of perspectives, including societal, employer, family, or health care provider. For example, from society’s point of view, medical costs may not be the most important cost category, particularly if government or another sector is absorbing the largest share; however, the health care provider may consider this to be the most important cost category. One suggestion was that it would be desirable to reach agreement on a hierarchy of issues to provide a measure of consistency. In addition, issues such as transfer payments and double-counting must be addressed and standardized.
Morbidity vs. Mortality
Merging morbidity and mortality costs for cost-effectiveness studies is desirable, as it provides a single denominator. However, this needs to be done with caution as morbidity costs are more intangible, incorporate more components and are often greater than mortality costs. When these costs are merged it is important to have clarity about why the study is being done and the context in which the results are being used.
The groups did not have sufficient time to address the glossary adequately, though it was generally agreed that the glossary was an excellent idea that warranted additional attention and revision, ideally on a regular basis. The glossary should be an organic document that is never considered to be ‘complete.’