Assessment of signs and symptoms after whiplash trauma

The timing of seeking healthcare following an injury is one factor that affects the outcome of an injury assessment made by insurance companies. Insurance companies and courts often refer to the 72—hour rule, stating that seeking healthcare more than 72 hours after trauma means that symptoms are not related to the whiplash trauma. The Swedish Whiplash Commission, with assistance of an expert group from the Swedish Medical Society, noted that although it is reasonable to assume that symptoms related to a whiplash trauma should be apparent within a few days after trauma, there is no scientific evidence to support a definite time limit for seeking healthcare [4]. Another factor influencing the outcome of injury assessment after whiplash trauma is the quality of documentation available from medical charts [4]. Early clinical investigation and proper documentation are essential to settle insurance claims and focus on the management of symptoms according to a Swedish structured management program for the treatment of symptoms after a whiplash trauma [15, 17, 21].

Gender differences in healthcare utilization

In a cross-sectional study by Osiaka et.al [22] of 1.6 million inhabitants in the region of Västra Götaland, a well-defined geographical region in south-western Sweden noted that women were more likely to receive more accessible, less expensive primary healthcare, while men were more likely to receive more expensive specialist inpatient care. Another study by Raine [23] suggest that women generally receive more low cost primary healthcare resources than men. Consequently it has been shown that men sometimes receive more resource and treatment than women, even when their illness/injury is the same [24]. Women referred to a cardiac rehabilitation program are less likely to be instructed on secondary prevention strategies [25–27]. Results from the Framingham Heart Study support the existence of gender-differences in rehabilitation after stroke, with poorer outcome observed in women [28].

Gender differences in whiplash injuries

Holm et al [12] showed there has been an increase in visits to emergency rooms due to whiplash trauma in the western world over the past 30 years, with women seeking care for WAD more often than men. They also found that headrests/car seats constructed to limit head retraction during rear-end collisions have been shown to be beneficial, especially to women [12]. Furthermore, women were found to have more symptoms related to whiplash trauma compared to men [29].

Gender differences in care-seeking behavior and overall management of patients after whiplash trauma can have a large impact on rehabilitation and financial compensation in the event of chronic health problems. It has previously been shown that gender differences concerning care-seeking behavior after whiplash trauma exists if the trauma is work related [30]. However, gender differences in care-seeking behavior for non-work related WAD is not yet studied. Hence, further elucidation of gender differences in patients exposed to a whiplash trauma is warranted.

This study aims to investigate gender differences in care-seeking behavior regarding time elapsed before seeking healthcare, type of healthcare facility sought, treatment given and length of hospital stay immediately after whiplash trauma.

Statistical analysis

A chi-square test was used to analyze differences between men and women in care-seeking behavior and the type of care received. Mann Whitney’s U-test was used to analyze differences between men and women concerning elapsed time between trauma and seeking care. Finally, a student’s t-test was used to compare the length of hospital stay between genders.

Multivariate linear regression was used to analyze the relation between the dependent variable patient delay between trauma and seeking care (days) and gender while adjusting for confiding variables such as age, work related accident and car traffic accident. Prior the multivariate linear regression, the variables were evaluated for the assumptions of linear regression. The dependent variable vas not normally distributed and subsequently transformed to ranked normal score using Blom´s formula [31]. Spearman Rank Correlation was used to decide which variables to put into the multivariate regression. All variables with significant correlation p <0.05 with the dependent variable in Spearman’s rank correlation was put forward into the final multivariate linear regression. The exact value of the beta coefficient as such makes no sense since the dependent variable is transformed. Hence, it is presented as being above or below zero to indicate the direction of a correlation. Statistical significance was set at p< 0.05. The statistical software IBM SPSS version 22 was used.

Gender and insurance claims

In this study, we can see a statistically significant gender difference where women seek healthcare later than men. This may also be clinically significant since it can potentially affect insurance outcomes, based on the theoretical link between care sought later and the willingness of insurance companies to award compensation. "The 72 hour rule” is commonly applied in connection with insurance claims in Sweden and Norway. Seeking care later (72 hours or more after trauma) is likely to reduce the probability of getting any compensation from insurance companies. As recently, as 2015 a study was commissioned by the insurance company Aviva to investigate what the UK can learn from overseas motor insurance companies when addressing rising claims for whiplash [32]. Frontier looked at five European countries, France, Germany, Norway, Spain and Sweden and suggested that the UK should also introduce the“72 hour rule” as a means of declining insurance claims [32]. “Other countries like Norway and Sweden have limitation periods and also require medical reports to be obtained within short periods (72 hours). MedCo could look to include this as part of the process.” [32]. Information from our study opens the way for future economic studies investigating the gender implications of late care seeking and its influence on possible compensation in case of chronic WAD. This study showed gender differences with a clear disadvantage for women. Therefore, future guidelines addressing WAD needs to consider using information channels suitable to both women and men.

Gender and choice of healthcare facility

This study found a statistically significant gender difference where women were more likely to initially seek care after a whiplash trauma at a primary healthcare facility compared to men. This gender difference is unlikely to be of any clinical significance for the single patient but might be of interest when planning allocation of health care resources.

One possible explanation for the difference in seeking level of care could be that in Swedish women visit a primary healthcare facility during pregnancy for antenatal care and postnatal care after childbirth, making it more likely that they would utilize a primary healthcare facility with other healthcare needs, like a whiplash injury [22]. Another explanation might be that women tend to be more burdened by guilt for having been involved in a traffic accident [33]. A further explanation could be women’s responsibility for the home and family means that women do not prioritize their own health, even in the presence of symptoms [34]. Finally, gender differences in health care seeking behavior may also be explained by that women and men are raised with different gender based expectations and structures within the family and labor market [35, 36].

The cultural gender norms mean men seek healthcare at hospital [37]. Similarly, the male role means that men are not ashamed of having been involved in a car accident [38]. According to Conell’s economical gender dimension, another alternative explanation for men attending healthcare early after trauma might be that men have the responsibility for insurance documents at home more often than women [38]. This might result in a greater understanding of the importance of early medical contact to gain adequate documentation and subsequent correct insurance compensation.

Methodological strengths

The main strength in this study is that it is based on clinical encounters in the healthcare system and is not limited to data from an insurance company. Data quality was strengthened as all patients included were examined by the physician in charge who documented and registered a diagnosis according to ICD-10 after taking a history and doing a clinical examination. The quality of this database was closely monitored with regular checks of data quality between 1998 and 2008, and data from this period is of very high quality.

Methodological weaknesses

One weakness is that there are no data regarding insurance claims or compensations in this study. Another weakness is that we have no information concerning how many women were mothers. We do know that the average age for women in this study was 34.0 years and the average age for first-time mothers in Sweden is 27–31 years. Hence, we may assume that a fair proportion of participating women also were mothers.

The missing trauma cases in the present study were 20%. There is no reason to believe that those who did not register were more seriously injured, although that is a possibility. Patients more seriously injured (Abbreviated Injury Scale, AIS 3–5) may have been registered as suffering from something other than neck distortion and whiplash, even if they also had those injuries. Awareness, knowledge and discussions of WAD in the society and among professionals has increased during the last 15 years making it less likely that symptoms indicative of a whiplash injury are ignored and not registered [10].

The level of WAD injury was not classified in the medical documentation, and it is not possible to do so retrospectively. Another limitation is that no follow-up was possible for individuals involved in a whiplash trauma. We can therefore not report the long-term fate or care of these patients. The study base, Skaraborg County, is not necessarily comparable with studies in cities with a population larger than 100,000 where traffic may be more intense.