Deployment-related injury and posttraumatic stress disorder in US military personnel

BACKGROUND

The current military conflicts in Iraq and Afghanistan have resulted in the most US casualties since the Vietnam War. Previous research on the association between deployment-related injury and posttraumatic stress disorder (PTSD) has yielded mixed results.

OBJECTIVES

To examine the effect of battle injury (BI) relative to non-battle injury (NBI) on the manifestation of PTSD symptoms in military personnel and to assess the demographic, injury-specific, and pre-injury factors associated with PTSD following a BI.

PATIENTS AND METHODS

A total of 3403 personnel with deployment-related injury (1777 BI and 1626 NBI) were identified from the Expeditionary Medical Encounter Database. Records were electronically matched to Post-Deployment Health Assessment (PDHA) data completed 1-6 months post-injury. The PTSD screening outcome was identified using a four-item screening tool on the PDHA.

RESULTS

Compared to those with NBI, personnel with BI had more severe injuries, reported higher levels of combat exposure, and had higher rates of positive PTSD screen. After adjusting for covariates, personnel with BI were twice as likely to screen positive for PTSD compared to those with NBI (odds ratio [OR], 2.10; 95% confidence interval [CI], 1.60-2.75). In multivariable analysis among battle-injured personnel only, moderate and serious-severe injury (OR, 1.49; 95% CI, 1.12-2.00 and OR, 1.64; 95% CI, 1.01-2.68, respectively), previous mental health diagnosis within 1 year of deployment (OR, 2.69; 95% CI, 1.50-4.81), and previous BI (OR, 1.96; 95% CI, 1.22-3.16) predicted a positive PTSD screen.

CONCLUSIONS

Military personnel with BI have increased odds of positive PTSD screen following combat deployment compared to those with NBI. Post-deployment health questionnaires may benefit from questions that specifically address whether service members experienced an injury during combat.

Postdeployment symptom changes and traumatic brain injury and/or posttraumatic stress disorder in men

In Operation Iraqi Freedom and Operation Enduring Freedom, blast-related injuries associated with combat are frequent and can result in traumatic brain injury (TBI) symptoms that may be difficult to distinguish from psychological problems. Using data from the Post-Deployment Health Assessment and Reassessment, we identified 12,046 male U.S. Navy sailors and Marines with reported combat exposure from 2008 to 2009. Symptoms potentially associated with blast-related TBI and posttraumatic stress disorder (PTSD) that were reported immediately after deployment were compared with symptoms present several months later. Our study supports others that have found that subjects with blast-related injuries may experience the development or worsening of symptoms during the months following deployment. Additionally, our study found that those who screened positive for PTSD and TBI formed a unique group, with the presence of TBI exacerbating development of PTSD symptoms at reassessment. Providers should recognize the late development of symptoms, consider the possibility of comorbidity, and be prepared to treat multiple symptoms rather than a specific diagnostic category.

Blast-related mild traumatic brain injury is associated with a decline in self-rated health amongst US military personnel

INTRODUCTION

Mild traumatic brain injury (MTBI) has emerged as the preeminent injury of combat from the recent conflicts in Iraq and Afghanistan. Very little is known about short- and long-term outcomes after combat-related MTBI. As a measure of outcome after injury, self-rated health is a reliable, widely used measure that assesses perceived health. The primary aim of this study was to determine the effect of combat-related MTBI on self-reported health status after return from deployment. The secondary objective was to examine predictors of a decline in self-reported health status amongst US service members with MTBI, as compared to those service members with other minor non-TBI injuries.

PATIENTS AND METHODS

MTBI cases and an injured comparison group were identified from the Expeditionary Medical Encounter Database records of 1129 male, US service members who experienced blast-related injuries in Iraq from March 2004 to March 2008. Self-rated health was assessed from the routinely administered pre- and post-deployment health assessment questionnaires by the following question, "Overall, how would you rate your health during the past month?" Possible responses were "poor", "fair", "good", "very good", or "excellent." A distinction was made between minor and major negative changes in health (i.e., very good to fair) based on these self-rated health outcomes captured post-injury.

RESULTS

For all personnel, post-injury levels of self-rated health were statistically significantly worse than pre-injury health rating. At 6months post-injury, service members with MTBI were 5 times more likely to report a major negative change in health as compared to members with other mild injuries. This association was independent of age, rank, branch of service, Injury Severity Score, mental health diagnosis prior to injury, and having been referred to a health care professional.

DISCUSSION

Blast-related injuries, specifically MTBI, during deployment have negative consequences on service members' perception of health. Future research is needed to improve our understanding of the overall effects of MTBI on health and quality of life.

Cigarette smoking, body mass index, and physical fitness changes among male navy personnel

INTRODUCTION

Cigarette smoking has been reported to be higher among deployed military men than among similarly aged civilian or nondeployed men, but the short-term effect of smoking on physical fitness among these young healthy men is unclear. This study examined self-reported smoking status and change in objectively measured fitness over 1-4 years while controlling for body mass index (BMI).

METHODS

This study included a large sample of male U.S. navy personnel who deployed to Iraq or Kuwait between 2005 and 2008. A mixed modeling procedure was used to determine factors contributing to longitudinal changes in both BMI and fitness (measured by run/walk times, curl-ups, and push-ups).

RESULTS

Of the total sample (n = 18,537), the 20% current smokers were more likely than nonsmokers to be enlisted, younger, and have lower BMI measurements at baseline. In addition, smokers had slower 1.5-mile run/walk times and could do fewer curl-ups and push-ups compared with nonsmokers. The run/walk time model indicated that over 4 years, smokers (compared with nonsmokers) experienced a significantly greater rate of decrease in cardiorespiratory fitness, even after controlling for changes in BMI.

CONCLUSIONS

These results call for continued attention to the problem of nicotine use among young healthy men.

Twin studies and the heritability of MS: a conclusion

OBJECTIVE

The classical twin study has the potential to evaluate the relative contribution of genes and environment and guide further research strategies, provided the sampling and methods of analysis are correct. We wish to review all the more informative twin studies on multiple sclerosis (MS).

METHODS

We examined six large population-based twin studies in MS and calculated indices of heritability (h(2)), which is the traditional method of assessing genetic contribution to disease and to allow comparison between studies.

RESULTS

This index was found to vary widely from 0.25 to 0.76 with large confidence intervals that reflect small sample size and prevent robust interpretation.

CONCLUSION

Overall the studies support a genetic contribution to disease; however, the imprecision of the heritability estimates and potential biases that they contain mean that very little inference can be drawn its exact size. Given that the magnitude of genetic effect cannot be measured because of the relative infrequency of MS; the consequent difficulty in collecting an informative sample; and in many countries, the lack of a comprehensive twin register, we suggest that further twin prevalence surveys should not be undertaken. Twin studies could be used more effectively in other ways, such as the co-twin case-control approach.

Schmorl's nodes: Common, highly heritable, and related to lumbar disc disease

OBJECTIVE

Schmorl's nodes (SN) are common, but little is known of their relationship with degenerative change and back pain or genetic and environmental factors influencing their expression. We studied healthy female twin volunteers to determine the prevalence and clinical features associated with SN.

METHODS

Serial sagittal T1- and T2-weighted magnetic resonance images of the lower thoracic and lumbar spine were analyzed in 516 healthy female twins (150 monozygotic and 366 dizygotic). The images were scored for lumbar degenerative change. Presence of SN was noted at cranial and caudal vertebral levels T9 to L5. Data on physical activity and back pain were collected by questionnaire. Heritability of SN was calculated using variance components modeling.

RESULTS

SN were found in 30% of subjects. Of the 374 SN, 153 (41%) were in the lumbar spine and 221 (59%) were in the thoracic spine. SN heritability was >70%. There was a positive association between SN and lumbar disc disease (LDD). SN were more frequent in subjects with back pain (for >/=2 SN: odds ratio [OR] 2.68, 95% confidence interval [95% CI] 1.11-6.47, P = 0.03), but this was largely accounted for by the association of SN with LDD (OR 1.97, 95% CI 0.78-5.0, P = 0.15 adjusted for LDD). No independent association of SN with back pain was identified.

CONCLUSION

SN are common in middle-aged women and are strongly genetically determined. They are associated with lumbar degenerative change, which is a risk factor for back pain, but are not themselves an independent risk factor for back pain.

The genetic contribution to hip joint morphometry and relationship to hip cartilage thickness

A twin study approach was used to explore the genetic determinants of hip joint morphometry and their relationship to hip cartilage thickness. Our analysis used data on anthropometric characteristics and radiographic features of a group of 222 monozygotic (MZ) and 240 dizygotic (DZ) twins. We confirmed that genetic factors account for most of the variation in minimal joint space (MJS) and acetabular anatomy. This genetic variation was largely due to factors unique to MJS itself and not explained by anthropometric variables or measurements of acetabular morphology. Only a small proportion was shared with genetic factors underlying acetabular shape, mainly the centre edge angle.

A gnathodynanometer as an objective means of pain assessment following wisdom tooth removal

There appears to be no information concerning changes in bite strength following wisdom tooth removal. A gnathodynanometer was constructed, calibrated and then tested on 20 normal subjects. Sixty five patients scheduled for third molar surgery were assessed by this device immediately before operation and on the seventh post-operative day. Post-operatively, they were asked to complete a McGill pain questionnaire (MPQ) and indicate their present pain on a numerical rating scale (NRS). Bite strength was reduced in all cases. The side which was most painful tended to have the larger reduction. The reduction in bite strength was found to have a highly significant correlation with the numerical rating scale and a significant correlation with the sensory descriptors of the McGill pain questionnaire. It would appear, therefore, that the gnathodynanometer holds promise as a research tool in oral surgery.

Open letter on family practice training

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Value of penicillin in the prevention of pain, swelling and trismus following the removal of ectopic mandibular third molars

A double-blind randomised placebo-controlled study of the value of systemic penicillin in preventing pain, swelling and trismus following the removal of impacted mandibular third molars and indicates that penicillin may be used justifiably in the more difficult cases.