Non-pharmacologic and Pharmacologic Treatments among Soldiers with and without Chronic Pain and/or Posttraumatic Stress Disorder

Abstract

Objective:

This study examined the prevalence of chronic pain (CP) alone, posttraumatic stress disorder (PTSD) alone, and CP with PTSD (CP/PTSD) during the postdeployment year in Army soldiers. For these clinical subgroups, we examined receipt of nonpharmacologic treatment (e.g., therapeutic exercise, chiropractor), prescription opioids and other pharmacologic treatments, and other healthcare services.

Methods:

The sample was active duty soldiers returning from an Afghanistan or Iraq deployment ending between October 1, 2008 and September 30, 2014. Bivariate statistics compared patterns of healthcare utilization among subgroups. Multivariate logistic regression with additional covariates identified predictors of receiving ≥31 days opioid supply among soldiers with CP, focusing on the role of PTSD alone and PTSD interacted with nonpharmacologic treatment.

Results:

Twelve percent of soldiers received a CP diagnosis, 5% received a PTSD diagnosis, and 1.8% had both conditions. Eighty percent of soldiers with comorbid CP/PTSD received nonpharmacologic treatment and 31.4% received ≥31 days-supply of opioids. Among soldiers with CP, comorbid PTSD and lack of nonpharmacologic treatment was associated with 1.4 (95% CI 1.3–1.6) increased odds of receiving ≥31 days opioid supply. PTSD in combination with specific nonpharmacologic treatment modalities had a varied relationship with opioid receipt, with only PTSD with acupuncture or biofeedback associated with reduced odds (0.8 CI 0.7–0.9).

Conclusion and Implications:

Soldiers with comorbid CP/PTSD have complex and significant healthcare needs. While mental health care and nonpharmacologic treatment were accessed by soldiers with CP/PTSD, additional interventions are needed to mitigate protracted opioid utilization.

INTRODUCTION

Both posttraumatic stress disorder (PTSD)¹ and chronic pain (CP) ² are prevalent and highly comorbid in the US population. A nationally-representative US study indicated that compared to individuals without PTSD, those with PTSD had a higher prevalence of musculoskeletal, digestive, and nerve pain conditions.³ For active duty and veteran populations, the comorbidity is especially noted. CP and PTSD rates are independently higher in active duty service members and veterans compared to their civilian counterparts,⁴ and co-occur with regular frequency after combat deployment.^5–9 Compared to the prevalence of PTSD in civilian populations with CP, the prevalence of PTSD in veterans with CP may be as high as 50%.¹⁰ As such, much of the literature examining the presence of and treatment for comorbid CP and PTSD comes largely from studies of veterans; though given the above statistics, the comorbidity is relevant across both civilian and military settings.

In addition to its prevalence, comorbid CP and PTSD may be associated with worse outcomes and quality of life, relative to having CP or PTSD alone. Compared to veterans with CP only, those with comorbid CP and posttraumatic stress symptoms reported higher pain intensity and levels of pain-related disability.⁶ Among veterans of the Afghanistan or Iraq conflicts who received care in the Veterans Health Administration (VHA) and received an opioid prescription, those who also had a PTSD diagnosis were more likely to receive opioids for pain diagnoses, higher-dose opioids, two or more concurrent opioids, concurrent hypnotic prescriptions, and early opioid refills than those without PTSD and those with other mental health conditions.¹¹ This was mirrored in a nationally representative US civilian sample where comorbidity of CP and PTSD was associated with a greater risk of opioid use disorder.³

It is well-established that mental health disorders among veterans, including PTSD, are associated with increased behavioral health and non-behavioral healthcare utilization,^12–14 yet fewer studies have focused on populations with comorbid chronic pain.^15,16 In a study of veterans treated in the VHA from 2002–2007, those with comorbid pain and PTSD had 7% more primary care visits and 25% more pain specialty visits than the CP-only group, and 46% more primary care visits than the PTSD-only group.¹⁷ Only around 50% of eligible veterans utilize healthcare services in the VHA after leaving the military,^18,19 thus, examining healthcare utilization patterns of military members in the Military Health System (MHS) provides a more complete picture of treatment received among individuals with CP and PTSD comorbidity.

Over the past several years, the MHS has taken steps to address both CP and PTSD with a patient-centered approach.²⁰ This includes establishing interdisciplinary and integrative pain management approaches,^21,22 and promoting clinical practice guidelines for delivering high quality mental health services for military members with PTSD.^23,24 These models often incorporate nonpharmacologic treatments for pain treatment and comorbid conditions.^25,26 The goal of this study was to examine the prevalence of CP alone, PTSD alone, and CP with PTSD during the postdeployment year in Army soldiers. For these clinical subgroups, we examined receipt of nonpharmacologic treatment (e.g., therapeutic exercise, chiropractor), prescription opioids, and other healthcare services. Lastly, because prior research has identified increased risk of adverse outcomes from opioid prescriptions,^27,28 among the subgroup with CP, we examined the association of PTSD with receipt of ≥31days supply of prescription opioids during the postdeployment year.

METHODS

Data sources

Data from 576,425 Army active duty soldiers was extracted from the MHS Data Repository for the Substance Use and Psychological Injury Combat (SUPIC) study. In the SUPIC study, data was included for all soldiers returning from an Afghanistan or Iraq deployment in fiscal years 2008 to 2014. Additional details on the methods for the SUPIC study are described in Larson et. al.²⁹ SUPIC data includes all pharmacy data, outpatient and inpatient specialist and non-specialist healthcare, from all ambulatory claims and admissions in military “direct care” settings and civilian “purchased care” settings covered by TRICARE. Other data sources included pain scores from vital records of the Clinical Data Repository, and deployment information from the Contingency Management System.

This study was approved by Brandeis University’s Committee for Protection of Human Subjects and the Human Research Protection Program at the Office of the Assistant Secretary of Defense for Health Affairs/Defense Health Agency conducted the human subjects review. The Defense Health Agency’s Privacy and Civil Liberties Office executed the data use agreements.

Sample Classification

The sample was classified by two characteristics observed during the postdeployment year: clinically significant CP and receipt of a PTSD diagnosis. Clinically significant CP was defined by duration of a pain diagnosis as the reason for care and duration of moderate or greater pain severity. Specifically, we required the presence of at least two ambulatory records with primary diagnoses of pain conditions identified in our prior research from the same pain category,³⁰ spanning at least 90 days during the year, and self-reported pain scores of 4 to 10 (moderate to severe) on the numeric pain rating scale of two or more encounters spanning at least 90 days.³¹ Soldiers classified as no CP may have received pain treatment but did not meet both duration and pain intensity definitions. PTSD was based on the presence of the ICD-9-CM diagnosis code 309.81 in any position, for any ambulatory or hospital care encounter. In sensitivity analysis we used a more conservative definition of PTSD, requiring either: 1 inpatient PTSD diagnosis; 2 outpatient PTSD diagnoses, or 1 PTSD diagnosis and a positive screen for PTSD on the Primary Care PTSD screen ^32,33 from the postdeployment health assessment or re-assessment surveys (81 percent of the sample). Because we were concerned about under diagnosis of PTSD in active duty soldiers by military providers,^34,35 we based our main analysis on the presence of one diagnosis.

Pharmacologic Treatments

To identify pharmacologic treatments for CP and PTSD, we analyzed records from the DoD Pharmacy Data Transaction Service, a comprehensive file which included all prescriptions dispensed to soldiers. Each prescription record contained the days-supply which we summed for the postdeployment year. We classified opioid prescription utilization during the postdeployment year as opioid days-supply≥7 and ≥31. Our definition of opioid prescriptions can be found in Adams et. al.³⁶ Using the therapeutic classification of the American Hospital Formulary System, we selected other pharmacologic treatments for analysis including tramadol (a weak opioid that was scheduled as a controlled drug in 2014), other analgesics, selective serotonin reuptake inhibitors/ selective serotonin norepinephrine re-uptake inhibitors (SSRI/SNRI), benzodiazepines, and antipsychotics. We calculated the mean annual days-supply for each medication class.

Nonpharmacologic treatment

Using procedure codes on ambulatory claims/encounters, we identified a set of nonpharmacologic treatment modalities that might be used for CP and/or PTSD conditions, based on our review of research and clinical guidelines studies.^37–39 Nonpharmacologic treatments were organized into four larger groups and were not mutually exclusive: (a) therapeutic exercise, (b) chiropractic and osteopathic spinal manipulation, (c) complementary procedures (acupuncture, biofeedback, cold laser), (d) and other physical therapy procedures (e.g., massage, heat, transcutaneous electrical nerve stimulation, traction, ultrasound, lumbar supports). All nonpharmacologic treatment were assessed during the postdeployment year.

Other Healthcare Utilization Measures

As descriptive measures of overall health status, we included summary measures for any inpatient admission, and the number of emergency department (ED) visits during the postdeployment year. Additionally, we included measures of mental health specialty treatment and substance use specialty treatment based on procedure codes.

Functional Measures

As a measure of functional ability, we also report whether soldiers received any outpatient encounter at a military treatment facility with a documented duty limitation (e.g., work restriction) for any reason inclusive of assignment to quarters, restricted duty, or admitted to hospital.

Statistical Analysis

We present estimates of healthcare service receipt among soldiers within four analytic subgroups: no CP or PTSD, CP-only, PTSD-only, and comorbid CP/PTSD. Statistical comparisons of percent with nonpharmacologic treatment utilization were made between CP groups (with and without PTSD) and between PTSD groups (with and without CP). For each medication class we compared mean total days-supply among users. Comparisons were made using Chi-square tests for categorical measures and the test of means for continuous measures, with significance set at p<0.001.

We conducted logistic regression models on annual opioid days-supply≥31 to assess the independent association of receiving a PTSD diagnosis, controlling for four nonpharmacologic treatment modalities. Given the dependent variable was opioid receipt, we restricted the analysis to the CP subgroup (n=70,309). To further investigate the potential role of PTSD as a moderator of nonpharmacologic treatments, interaction terms of PTSD status times each nonpharmacologic treatment modality were added to the regression model. Analyses controlled for age, sex, race/ethnicity, marital status, fiscal year of end of deployment, and military rank. Adjusted odds ratio coefficients with 95% confidence intervals and p values are reported.

We conducted a sensitivity analysis by re-estimating the logistic regression restricting our sample to soldiers who me the more conservative definition of PTSD defined above (81% of the PTSD subsample).

RESULTS

The SUPIC active duty cohort (n=576,425) is predominantly male (89.3%), White/non-Hispanic (57.1%), married (58.4%), and age 18–24 (40.1%). Among the cohort, 12.2% met the definition for clinically significant CP during the postdeployment year. Among soldiers with CP, 14.4% had a comorbid PTSD diagnosis. Among soldiers without CP, 3.8% received a PTSD diagnosis. Among all sociodemographic and military characteristic subgroups, the prevalence of PTSD diagnosis was higher among soldiers with CP than those without CP (Appendix 1).

Over half of soldiers with comorbid CP/PTSD received opioid days-supply≥7 in the postdeployment year, and nearly one-third received opioid days-supply≥31, which was higher than all other subgroups (Table 1). Over one-third of the comorbid CP/PTSD group received tramadol, which was most common in the comorbid subgroup. Receipt of other analgesic medications was nearly universal among soldiers with CP, although the average days-supply was higher among soldiers with CP/PTSD than in those with CP-only. Regarding medications most commonly associated with psychiatric diagnosis, percent utilization of SSRI/SNRI’s, benzodiazepines, and anti-psychotics was higher for soldiers with PTSD or CP than those without these diagnoses and was highest for those with comorbid CP/PTSD. More than one-third of the soldiers with comorbid CP/PTSD received a benzodiazepine prescription and one-third received an antipsychotic prescription.

Table 1.

Prescription utilization and mean days-supply during the postdeployment year among active duty soldiers with and without chronic pain, by PTSD status (n=576,425)¹

Type of prescription	No Chronic Pain				Chronic Pain1
	No PTSD (n = 486,984)		PTSD (n = 19,132)		No PTSD (n = 60,156)		PTSD (n = 10,153)
	n	Percent	n	Percent	n	Percent	n	Percent
Opioid days-supply ≥7 in year	59,823	12.3	4,528	23.7	24,113	40.1	5,513	54.3
Opioid days-supply ≥31 in year	15,951	3.3	1,852	9.7	10,271	17.1	3,191	31.4
Tramadol prescription	28,848	5.9	2,318	12.1	18,232	30.3	3,551	35.0
Annual days-supply, mean (SD)	20.6± 35.8		27.5± 42.2		32.0± 54.5		38.7± 61.5
Other analgesic prescription	277,914	57.1	14164	74.0	57,537	95.6	9,723	95.8
Annual days-supply, mean (SD)	49.3± 54.7		67.7± 70.1		101.1± 81.7		122.8± 99.5
SSRI or SNRI prescription	47,728	9.8	13203	69.0	17,624	29.3	8,496	83.7
Annual days-supply, mean (SD)	117.0± 122.2		177.7± 154.6		138.4± 138.7		240.0± 191.2
Benzodiazepine prescription	29,844	6.1	3,756	19.6	9,156	15.2	3,585	35.3
Annual days-supply, mean (SD)	18.2± 33.1		50.4± 66.0		28.8± 49.4		68.9± 93.7
Anti-psychotic prescription	5,931	1.2	4,664	24.4	2,349	3.9	3,361	33.1
Annual days-supply, mean (SD)	77.5± 89.9		101.9± 103.3		87.4± 108.5		122.3± 126.4

¹At least 2 ambulatory records with primary diagnoses of the same pain category condition spanning at least 90 days during the year, combined with self-reported pain scores of 4 to 10 (moderate to severe) on the numeric rating scale of 2 or more encounters spanning at least 90 days.

Note – Chi-square statistic for each bivariate association of PTSD status and PTSD subgroups was significant at the p ≤.001 level except for other analgesic prescriptions in among the PTSD groups. Abbreviations: PTSD = posttraumatic stress disorder, SD = standard deviation, SSRI/SNRI = Selective serotonin reuptake inhibitors or serotonin-norepinephrine reuptake inhibitors

Receipt of nonpharmacologic treatment and specialty behavioral healthcare was highest among soldiers with comorbid CP/ PTSD (Table 2). More than three-fourths of soldiers with comorbid CP/PTSD received at least one nonpharmacologic treatment, significantly higher than soldiers with CP-only and more than double the percent of soldiers with PTSD-only. The majority of the CP/PTSD group received therapeutic exercise. Utilization of mental health specialty treatment was nearly universal among subgroups with PTSD. Utilization of specialty substance use treatment was higher among the subgroups with comorbid CP/PTSD and PTSD-only compared to subgroups without PTSD.

Table 2.

Nonpharmacologic and specialist service utilization during the postdeployment year among active duty soldiers with and without chronic pain, by PTSD status (n=576,425)¹

Type of service	No Chronic Pain				Chronic Pain
	No PTSD (n = 486,984)		PTSD (n = 19,132)		No PTSD (n = 60,156)		PTSD (n = 10,153)
	n	Percent	n	Percent	n	Percent	n	Percent
Any nonpharmacologic treatment	92,536	19.0	7,355	38.4	41,656	69.2	8,150	80.3
Therapeutic exercise	80,461	16.5	5,990	31.3	37,743	62.7	7,347	72.4
Chiropractic or spinal manipulation	19,861	4.1	1,460	7.6	13,013	21.6	2,467	24.3
Acupuncture, biofeedback, cold laser	4,395	0.9	1,337	7.0	3,191	5.3	1,955	19.3
Other physical therapy procedures2	46,607	9.6	3,705	19.4	28,996	48.2	5,894	58.1
Mental health specialty	259,048	53.2	18,347	95.9	45,399	75.5	10,050	99.0
Substance use specialty	26,347	5.4	3,150	16.5	4,652	7.7	1,714	16.9

¹At least 2 ambulatory records with primary diagnoses of the same pain category condition spanning at least 90 days during the year, combined with self-reported pain scores of 4 to 10 (moderate to severe) on the numeric rating scale of 2 or more encounters spanning at least 90 days.

²Includes Massage, heat, TENS, traction, ultrasound, lumbar supports.

Note – Chi-square statistic for each bivariate association of PTSD status and PTSD subgroups with utilization was significant at the p ≤.001 level. Abbreviations: PTSD = posttraumatic stress disorder.

Soldiers with comorbid CP/PTSD had the highest utilization of overall healthcare services and were the most likely to experience a duty limitation compared to other subgroups (Table 3). Approximately one-third of soldiers with comorbid CP/PTSD had an inpatient admission; this was greater than for those with CP-only (11.5%) or PTSD-only (22.3%). Nearly two-thirds of soldiers with comorbid CP/ PTSD had an ED visit. The PTSD-only group had nearly twice the rate of inpatient admissions, and equivalent rates of ED use, as the CP-only group.

Table 3.

Healthcare utilization and duty limitations during the postdeployment year among active duty soldiers with and without chronic pain, by PTSD status (n=576,425)¹

Overall utilization	No Chronic Pain				Chronic Pain
	No PTSD (n = 486,984)		PTSD (n = 19,132)		No PTSD (n = 60,156)		PTSD (n = 10,153)
	n	Percent	N	Percent	n	Percent	n	Percent
Inpatient admission	22,313	4.6	4,274	22.3	6,935	11.5	3,337	32.9
Emergency department visit	127,384	26.2	9,418	49.2	30,042	49.9	6,694	65.9
Had military duty limitation, assigned to quarters, or admitted to hospital2	197,601	40.6	12,635	66.0	54,148	90.0	9,559	94.1

¹At least 2 ambulatory records with primary diagnoses of the same pain category condition spanning at least 90 days during the year, combined with self-reported pain scores of 4 to 10 (moderate to severe) on the numeric rating scale of 2 or more encounters spanning at least 90 days.

²Had outpatient encounter at a military treatment facility with disposition of assignment to quarters, restricted duty, or admitted to hospital

Note – Chi-square statistic for each bivariate association of PTSD status and PTSD subgroups with utilization was significant at the p ≤.001 level. Abbreviation PTSD = posttraumatic stress disorder.

The results of the logistic regression model shows that soldiers with a PTSD diagnosis and no use of nonpharmacologic treatment modalities had 1.4 times higher odds of receiving an opioid days-supply≥31 relative to soldiers without PTSD (Table 4). The coefficients for the interaction terms of PTSD and nonpharmacologic treatment indicated their effect on opioid receipt for the group with PTSD. Soldiers with PTSD who received chiropractic/spinal manipulation services had increased odds of receiving an opioid days-supply≥31 relative to those with no chiropractic/spinal manipulation care. Those with PTSD who received acupuncture, biofeedback or cold laser had reduced odds of receiving an opioid days-supply≥31 relative to those without such care. The coefficients for the other interaction terms were not significant. The coefficients for covariates indicated significantly reduced odds of receiving an opioid days-supply≥31 among females, the youngest age group (relative to age 30–34), black non-Hispanic, Hispanic, and other race-ethnicity (relative to white), and all ranks (relative to junior enlisted). The odds of receiving an opioid days-supply≥31 were higher among married soldiers (relative to never married), and Asian/Pacific Islander soldiers (relative to white/non-Hispanic).

Table 4.

Adjusted odds ratios for receipt of opioid days-supply≥31 during postdeployment year among active duty soldiers with chronic pain (n= 70,309)¹

Covariates	Adjusted Odds Ratio	(95% CI)	p-value
PTSD	1.4	(1.3, 1.6)	<.001
Therapeutic exercise	1.3	(1.2, 1.4)	<.001
Chiropractor or spinal manipulation	0.7	(0.7, 0.7)	<.001
Acupuncture, biofeedback, or cold laser	1.3	(1.1, 1.4)	<.001
Other physical therapy or TENS	1.8	(1.7, 1.9)	<.001
Mental health specialist	1.6	(1.6, 1.7)	<.001
Substance use specialist	1.3	(1.3, 1.4)	<.001
PTSD x therapeutic exercise	1.1	(1.0, 1.3)	0.050
PTSD x chiropractor or spinal manipulation	1.2	(1.1, 1.4)	<.001
PTSD x acupuncture, biofeedback, or cold laser	0.8	(0.7, 0.9)	0.007
PTSD x other physical therapy or TENS	1.1	(1.0, 1.2)	0.172
Female (reference group male)	0.9	(0.8, 0.9)	<.001
Age group (reference group 30–34)
18–24	0.9	(0.8, 0.9)	0.014
25–29	1.0	(0.9, 1.1)	1.000
35–39	0.9	(0.9, 1.0)	0.026
40+	1.0	(0.9, 1.1)	0.861
Marital status (reference group never married)
Married	1.2	(1.1, 1.2)	<.001
Separated	1.1	(1.0, 1.2)	0.018
Race/Ethnicity (reference group white, non- Hispanic)
American Indian or Alaskan Native	0.9	(0.8, 1.2)	0.778
Asian or Pacific Islander	1.2	(1.1, 1.3)	<.001
Black, non-Hispanic	0.6	(0.5, 0.6)	<.001
Hispanic	0.7	(0.6, 0.7)	<.001
Other	0.7	(0.6, 0.9)	0.003
Fiscal Year of return from index deployment (reference group = 2008)
2009	0.6	(0.5, 0.6)	<.001
2010	0.6	(0.5, 0.6)	<.001
2011	0.6	(0.5, 0.6)	<.001
2012	0.5	(0.4, 0.5)	<.001
2013	0.4	(0.3, 0.4)	<.001
2014	0.4	(0.3, 0.4)	<.001
Rank (reference group = junior enlisted/E1–3)
Senior enlisted	0.9	(0.8, 0.9)	1.000
Junior officer	0.8	(0.8, 0.9)	0.005
Senior officer	0.8	(0.6, 0.8)	0.008
Warrant officer	0.8	(0.7, 0.9)	0.114

¹At least 2 ambulatory records with primary diagnoses of the same pain category condition spanning at least 90 days during the year, combined with self-reported pain scores of 4 to 10 (moderate to severe) on the numeric rating scale of 2 or more encounters spanning at least 90 days. Abbreviation: TENS = Transcutaneous electrical nerve

In sensitivity analysis restricted to confirmed PTSD cases (81% of PTSD sample), these findings were replicated and the coefficients and CIs on the key independent variables were nearly identical, although significance level changed from p <.05 to p <.066 for the interaction of PTSD and therapeutic exercise reflecting the smaller sample size.

DISCUSSION

These findings highlight the unique healthcare needs of patients with comorbid CP/PTSD in a population of active duty soldiers returning from deployment. We found that 12.2% had clinically significant CP with self-report of moderate-severe pain intensity that lasted >3 months in the postdeployment year. Among soldiers with CP, 14.4% had a comorbid PTSD diagnosis, representing 1.8% of the entire active duty study population (n=10,153; data not shown). Soldiers with comorbid CP/PTSD had substantially greater healthcare utilization, including nonpharmacologic treatment, inpatient hospitalizations, and emergency visits. Furthermore, nearly all had documented limited duty restrictions or days out of work. Though such healthcare utilization patterns suggest overall burden, these analyses did not determine whether the non-nonpharmacologic treatment healthcare utilization occurred first, followed by nonpharmacologic treatment-based care. Research is warranted to understand the extent to which early and intensive healthcare intervention mitigates the risk of more expensive healthcare encounters (e.g., hospitalizations) and whether work impairment is influenced by treatment choices (e.g., associated with use of opioids or benzodiazepines).

Recent VA/DoD clinical guidelines urge providers to select short duration opioids when prescribing opioids in treatment of pain and suggest nonpharmacologic treatment as the first line in managing chronic pain.²⁸ In one case-control study of over 18,000 soldiers, those with opioid dependence were 28 times more likely to have a prior PTSD diagnosis than controls.⁴⁰ To improve guideline-concordant care, close monitoring of continued benefits among patients receiving opioids may mitigate the risk of adverse effects, particularly among those with PTSD. Interdisciplinary pain management approaches and nonpharmacologic treatment have been found effective in treating chronic pain,^39,41,42 and the MHS has expanded access to interdisciplinary pain management.^43,44 In the present sample, 16.9% of soldiers with comorbid CP/PTSD were seen by substance use specialists; future research should examine the utility of involving behavioral health clinicians at the time of the decision to initiate opioids among soldiers, particularly those with PTSD. While our data focuses primarily on active duty soldiers, the implications of this study could be beneficial to civilians. Similar to our findings, opioid prescription use is documented to be higher among civilians with PTSD and chronic pain.⁴⁵ Moreover, the likelihood of opioid use disorder among civilians with PTSD and chronic pain is higher than those without either conditions.³

Nonpharmacologic treatment such as acupuncture, yoga, cognitive-behavioral therapy and meditation have been associated with clinical improvements of PTSD symptoms or clinical improvements in managing both PTSD and CP.^46–52 The VA/DoD Clinical Practice Guideline for Management of Posttraumatic Stress Disorder and Acute Stress Reaction suggests that mindfulness, yoga, acupuncture, massage may facilitate a relaxation response.⁵³ Consistent with this, our study finds that receipt of acupuncture, biofeedback, or cold laser was more likely to be associated with reduced opioid use for those with comorbid CP/PTSD than for those with CP-only. Our data shows spinal manipulation to be effective for soldiers with CP but not in the presence of PTSD. Future research should examine if there is something about spinal manipulation that exacerbates hyperarousal or other PTSD symptoms.

We report very high utilization of mental health specialty treatment among soldiers with PTSD and note that the MHS has worked to identify PTSD among military members, including systematic screening for PTSD after deployment.³² We could not assess from the medical record the degree to which behavioral health therapy was trauma-focused, nor did we assess the duration or timing of therapy.

Overall, the present findings highlight the need for integrative, patient-centered models of care to ensure patients with CP or PTSD are assessed (early) for comorbid conditions, given their prevalence and increased subsequent healthcare utilization. As healthcare systems move to adopt value-based initiatives, it is important to consider the unique healthcare needs of those with comorbid CP/PTSD, such as the role of coordinating care among multiple providers and consolidating multidisciplinary treatments in single clinics (e.g., multidisciplinary pain or behavioral health centers). Mitigating the risk of inpatient and ED admissions in patients with comorbid CP/PTSD through more intensive treatment schedules and coordinated care, may not only improve patient outcomes, but reduce long-term healthcare costs and burden overall.

Limitations

There are several limitations to this study, primarily associated with the observational study design and reliance on secondary analysis of administrative data. Without random assignment to treatment, we cannot infer any causal relationships. Further, we did not study the sequence of diagnoses and treatment events; thus, we cannot distinguish the causal relationship between CP and PTSD, or causal relationships between these conditions and their comorbidity with healthcare utilization. It is likely that the prevalence of PTSD was underestimated because it required utilization of services that resulted in the identification of a diagnosis rather than population screening and assessment. Finally, opioid prescribing for active duty service members began to decline in 2011⁵⁴ in the middle of our study window. While we did include a measure of fiscal year of end of deployment in the logistic regression models to control for changes over time, additional research is needed to determine if study findings persist as prescribing trends continue to change after the end of our study period.

Conclusion

Soldiers with comorbid chronic pain and PTSD have complex treatment needs and require access to specialty care. This study provided evidence that mental health specialty services were widely utilized, but some nonpharmacologic modalities may be underutilized. Results also reflected a high prevalence of opioid receipt and prescriptions for benzodiazepines and antipsychotic medications that warrant close monitoring, particularly among soldiers with comorbid CP/PTSD. Future studies should assess the impact of MHS-wide changes to pain management and mental health care in improving guideline-concordant care.

Highlights:

• In the postdeployment year, posttraumatic stress disorder (PTSD) was three times more common among soldiers who had chronic pain (CP) compared to soldiers without such pain.

• Receipt of opioids for greater than 30 days was almost twice as likely in soldiers with CP and PTSD, than for those with CP absent PTSD.

• 80% of soldiers with CP and PTSD received some nonpharmacologic treatment, most commonly therapeutic exercise.

• 99% of soldiers with a PTSD diagnosis were seen by a mental health clinician.

Previous presentation:

• The Military Health System Research Symposium, Kissimmee, FL, August 2017

• The College on Problems of Drug Dependence, San Diego, CA, June 2018