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Suicide Among Vietnam-Era Veterans
FOOTNOTES
Author affiliation: 1 Department of Psychiatry, Washington University School of Medicine, St.
Louis, MO, 63108. 2 David M. Ledgerwood is now at the Department of Psychiatry, University
of Connecticut Health Center, Farmington, CT, 06030. 3 Department of Surgery, St. Louis
University Health Sciences Center, St. Louis, MO, 63110. 4 Surgical Service, Department of
Veterans Affairs Medical Center, St. Louis, MO, 63103. 5 Department of Mathematics,
Washington University, St. Louis, MO, 63105.
Reprint address: Rumi Kato Price, Department of Psychiatry, Washington University School of
Medicine, 40 N. Kingshighway, Suite 2, St. Louis, MO 63108-1332.
Risk of Completed and Attempted Suicide in Middle-Aged Vietnam-Era Veterans:
Results from Two National Samples
Rumi Kato Price1, David M. Ledgerwood1,2 , Nathan K. Risk1, Katherine S. Virgo3,4,
Edward L. Spitznagel5, Collins E. Lewis1
Suicide Among Vietnam-Era Veterans
Running Head: Suicide Among Vietnam-Era Veterans
Word Counts: abstract 99; text 4474 (excluding acknowledgments and references)
Tables and Figures: number of tables, 3; number of figures, 0.
MeSH keywords: suicide, suicide attempt, veterans, Vietnam, psychiatric disorders,
substance use disorders
Risk of Completed and Attempted Suicide in Middle-Aged Vietnam-Era Veterans:
Results from Two National Samples
Suicide Among Vietnam-Era Veterans - 2
Abstract
A lingering controversy exists regarding the extent of suicidal risk among Vietnam veterans.
Using two large national data sets, we examined risk for suicidality among Vietnam-era veterans
ages 40 to 60 who currently constitute 23% in this age group of U.S. men. Compared to others of
this age group, the odds ratio was 1.96 for Vietnam-era veterans’ completed suicide, and 1.51 for
attempted suicide. The excess risk appears to result from incremental differences in several
demographic and behavioral factors. A comprehensive intervention targeting physical, mental
health, and substance abuse problems would reduce suicidal risk among aging at-risk Vietnam-
era veterans.
Suicide Among Vietnam-Era Veterans - 3
Risk of Completed and Attempted Suicide in Middle-Aged Vietnam-Era Veterans:
Results from Two National Samples
More attention has recently been given to the prevention of adolescent suicide (Gould,
Greenberg, Velting, & Shaffer, 2003; Novick, Cibula, & Sutphen, 2003) and suicide in the
elderly (Ron, 2002; Waern, Rubenowitz, & Wilhelmson, 2003) than to suicide in mid-life.
Recent statistics for the United States show the suicide rate among the 40 to 60 age group in
2001 as 23.14 per 100,000 for males and 6.89 for females (CDC, 2003), and these rates have
been relatively stable over the past three decades (Riggs, McGraw, & Keefover, 1996). Among
males, the rate in 2001 compares to a suicide rate of 16.63 per 100,000 in youth (ages 15-24) and
35.29 per 100,000 in the elderly aged 70 years or older (CDC, 2003). These figures indicate that
the suicide rate for middle-aged men is actually higher than the rate for men in younger age
groups. A critical gap exists in our knowledge about the epidemiology and prevention of suicide
in middle-aged men, perhaps reflective of the reluctance of males in this age group to seek help
(Moller-Leimkuhler, 2003).
Approximately 9.2 million individuals served in the U.S. military during the Vietnam-era
period (August 1964 to April 1975), of whom about 3.4 million were deployed in Vietnam
(Department of Veteran Affairs, 2003). Almost three decades later, Vietnam-era veterans
currently make up about 23% of men in the age group of 40 to 60 years old in the U.S. (CDC,
2003). The estimates of completed suicide among Vietnam-era veterans, however, have varied
among reports (Pollock, Rhodes, Boyle, Decoufle, & McGee, 1990). Evidence for an excess risk
for suicide among Vietnam-era veterans is equivocal (Bullman & Kang, 1995) depending on
Suicide Among Vietnam-Era Veterans - 4
many factors including deployment to Vietnam (Watanabe & Kang, 1995), military branch
(Crane, Barnard, Horsley, & Adena, 1997), rank, age group, years since discharge (CDC Vietnam
Experience Study, 1987), and draft eligibility (Hearst, Newman, & Hulley, 1986). It is difficult to
assess accurately the excess risk of suicide among Vietnam-era veterans in part because of a
“healthy worker effect” (Crane et al., 1997). Veteran cohorts tend, in general, to be healthier than
their civilian counterparts because of the selection process for military service as well as the
requirement to maintain a specified level of physical fitness. Indeed, mortality studies of
veterans show that their overall mortality rate is significantly lower than the rates of comparable
civilian groups. This appears to hold true across different eras, genders (Thomas, Kang, &
Dalager, 1991), and nationalities (Crane et al., 1997). Nonetheless, suicide risk appears to be
elevated among selected subgroups of veterans, such as Vietnam veterans with combat exposure
(Farberow, Kang, & Bullman, 1990) or physical injury (Bullman & Kang, 1996), when compared
with other groups of Vietnam veterans or other veterans.
Psychiatric and environmental risk factors for suicidality have been well delineated
through decades of research (Clark & Fawcett, 1992; Blumenthal & Kupfer, 1990; Moscicki,
1997). Furthermore, general population and clinical studies have found common predictors of
both completed suicide and non-fatal suicidality, such as aging (Owens, 1990), not being married
(Petronis, Samuels, Moscicki, & Anthony, 1990), living alone (Owens, 1990), feeling hopeless
(Wetzel, 1976), having a physical illness (Perry, Jacobsberg, & Fishman, 1990), having a
psychiatric illness (Nordentoft & Rubin, 1993), particularly depression (Hintikka et al., 1998;
Kovacs, Goldston, & Gatsonis, 1993), as well as alcoholism (Murphy, 1992; Lewis, Rice,
Andreasen, Clayton, & Endicott, 1985) and drug abuse (Saxon, Aldrich, & Kuncel, 1978; Roy,
Suicide Among Vietnam-Era Veterans - 5
2001).
Among veteran populations, psychiatric disorders in general (Fontana & Rosenheck,
1995; Thompson, Katz, Kane, & Sayers, 2000), but more specifically post-traumatic stress
disorder (PTSD) (Kramer, Lindy, Green, Grace, & Leonard, 1994; Drescher, Rosen, Burling, &
Foy, 2003) and depression (Farberow et al., 1990), are associated with both suicide and non-fatal
suicidality. In addition, predictors of suicidality among combat veterans include physical trauma
(Bullman & Kang, 1996) and survivor guilt (Hendin & Hass, 1991; Hyer, McCranie, Woods, &
Boudewyns, 1990). Comorbidity of PTSD, depression, and other psychiatric difficulties appears
to be associated with greater exposure to traumatic events (Engdahl, Dikel, Eberly, & Blank,
1998; Beckham et al., 1998). Both alcoholism (Windle, 1994; Fu et al., 2002) and drugs (Price,
Risk, Haden, Lewis, & Spitznagel, in press) have also been linked to increased suicidality among
Vietnam veterans.
No studies, to our knowledge, have systematically compared veterans with non-veteran
men of the same age group to identify common and unique risk and protective factors that predict
both completed and attempted suicide. The current study analyzes two large general-population
data sets to examine death by suicide and non-fatal attempted suicide among Vietnam-era
veterans between the ages 40 to 60, compared with all other men of the same age group. The first
data set, the 1993 National Mortality Followback Survey (NMFS), contains information about
deceased individuals, and provides information about factors that may have contributed to the
completed suicide (CDC, 1998). The second data set, the National Longitudinal Alcohol
Epidemiologic Survey (NLAES) (Grant, Peterson, Dawson, & Chou, 1994), includes measures of
suicidal ideation and suicide attempts from in-person interviews with individuals (Grant &
Suicide Among Vietnam-Era Veterans - 6
Hasin, 1999). Both data sets include large numbers of men between the ages of 40 to 60, and
both surveys were conducted during the same time period. Furthermore, each data set includes a
sufficient number of similar measures of risk and protective factors for suicidality, thus providing
a unique opportunity to compare common and unique factors for completed and attempted
suicide.
The current study has practical and clinical significance not only for the well-being of
veterans but also for their family members and the healthcare system at large. The rate of suicide
in this sizable population of Vietnam-era veterans is expected to increase as they grow older.
Examining the issue of suicide as a possible long-term adverse consequence of war will allow the
mental health system to better understand the needs of military service veterans and prepare for
the potentially increasing morbidity of currently active U.S. service men (NYT, 2004) in the
future.
MATERIALS AND METHODS
Data sets
The 1993 National Mortality Followback Survey (NMFS) collected data on individuals
across the United States who were 15 years and older and who died in 1993. Three linked records
for 22,957 decedents constitute the NMFS data set, including death certificate information, a
proxy respondent questionnaire, and medical examiner records for deaths. Death certificates from
the Current Mortality Sample represented a 10% probability sample of death certificates received
by the National Center for Health Statistics (which in turn was about 10% of all deaths occurring
in the U.S. in 1993) (NMFS, 1998). The proxy interviews were completed with next-of-kin, or, if
Suicide Among Vietnam-Era Veterans - 7
next-of-kin was unavailable, another person who was familiar with the decedent. African
Americans and those who died of external causes including suicide were among several
oversampled groups.
The National Longitudinal Alcohol Epidemiologic Survey (NLAES) was conducted in
1992 by the Bureau of the Census under the design and sponsorship of the National Institute on
Alcohol Abuse and Alcoholism. The NLAES is a national probability household survey of the
population aged 18 years and older in the contiguous 48 states. One adult was selected at random
from each household resulting in a representative sample of the civilian, non-institutionalized
population (n = 42,862) (Grant et al., 1994). This large cross-sectional national survey contains
sufficient information on risk and protective factors for non-fatal suicidality (Grant & Hasin,
1999).
The portions of the two data sets available in the public domain without respondents’
identifiers were analyzed. In both data sets, the Vietnam-era veteran category is defined as U.S.
men who served in the military between August 1964 through April 1975. This included both
those who were, and who were not, deployed to Southeast Asia during the Vietnam conflict. The
age group of 40 to 60 years was selected for the current study. This age group represented 76.2%
and 81.3% of the Vietnam-era veterans in the NMFS and NLAES respectively. A total of 2,825
men were selected from the NMFS data set, consisting of 494 (17.5%) Vietnam-era veterans and
2,331 “other” men (all men except Vietnam-era veterans). The sample excluded 19.4% (n = 675)
of the deceased in this age category of men due to missing proxy interviews. The unweighted rate
of completed suicide was 9.0% in the excluded group compared to 8.9% among those included in
the current study. From the NLAES, a total sample of 5,462 men were selected, consisting of
Suicide Among Vietnam-Era Veterans - 8
1,277 (23.4%) Vietnam-era veterans and 4,185 “other” men.
We did not include men of the entire age range of Vietnam-era veterans because of the
study’s focus on middle-aged men. Such inclusion criteria would have reduced the advantage of
examining common factors, since predictors of suicidality are substantially different across age
groups (Conwell et al., 1998). The excluded age groups of Vietnam-era veterans in the NMFS
sample were 14.2% who were younger than 40 and 9.6% who were older than 60. In the NLAES,
13.4% were younger than 40 and 5.3% were older than 60. Given the small numbers of Vietnam-
era veterans in these age categories (e.g., n = 62 deceased veterans ages 61 or older in NMFS),
analyses separately of these sub-samples were judged under-powered.
Measures
NMFS. Cause of death was determined by the death certificate. Medical
examiner/coroner reports were gathered for individuals whose cause of death was homicide,
suicide, accident or undetermined (NMFS, 1998). Two non-fatal suicidality questions concerning
the deceased were available from the proxy interviews: communication of suicide intent (“At any
time in the last month of life, did (name) ever talk about taking his own life?”) and morbid
thought (“During the last month of life, did (name) express a wish to die, or say that he wished
that death would come quickly?”). The veteran’s status and a number of variables known to be
associated with suicide were included in the proxy questionnaire.
NLAES. This survey was designed to assess a variety of psychiatric disorders and
substance use disorders, with an emphasis on alcohol-related behaviors, according to the
Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) (APA, 1994).
Three questions were included in the depression section: morbid thought (“During that time
Suicide Among Vietnam-Era Veterans - 9
when your mood was at its lowest/you enjoyed or cared least about things, did you ...feel like you
wanted to die?”), suicidal ideation (“... think about suicide from time to time?”) and attempted
suicide ( “... attempt suicide?”). These questions were asked for lifetime conditioned on
depressed mood, but the section also assessed past-year suicidality without depressed mood.
Other variables selected for the current study were also obtained from self-report by the
probands.
Differences between NMFS and NLAES. The outcome measures of the two data sets
were different: while non-fatal suicidality was assessed in both surveys, completed suicide was
assessed only in the NMFS, and attempted suicide only in the NLAES. Furthermore, the NMFS
identified predictors of completed suicide compared to other deaths, whereas the NLAES
identified predictors of attempted suicide in comparison to no suicide attempts.
Ten predictor measures available in both the NMFS and the NLAES were selected after
an initial series of analyses. These included age, race, education, employment, marital status,
living alone, alcohol problems, drug use problems, depression, and health problems. The
measures differed in three important ways. First, the NMFS information was collected from
death documents and proxy interviews, and the NLAES information was obtained from live
probands. Second, the measures used for each survey differed in scope and time frame (Table 1).
The measures of alcohol problems, drug use, and depression were assessed for the past year in
the NMFS, whereas they were assessed for lifetime in the NLAES. Third, because the NMFS
data were based on proxy interviews, precise diagnostic categorization was not possible. Thus,
alcohol problems represented a syndrome approximating alcohol dependence; similarly,
depression represented a syndrome suggestive of major depression. DSM-IV diagnoses of
Suicide Among Vietnam-Era Veterans - 10
alcohol dependence and major depression were available from the NLAES data set.
Data analysis
Taking advantage of large sample sizes of the two surveys, prevalence rates of suicidality
were obtained separately for the Vietnam-era veterans and “others.” Because the NMFS survery
contains only the deceased respondents, estimates of the number of suicides were separately
obtained by combining the information from the NMSF data and vital statistics for the entire
population corresponding to the two groups of men in the age group 40 to 60.
Weighted estimates of prevalence rates, and coefficients for logistic regressions were
obtained with standard errors adjusted by the SUDAAN Taylor series linearization method
(Shah, Barnwell, & Bieler, 1996). The differences in prevalence rates of suicidality, as well as
demographics and behavioral characteristics, between the two groups were assessed for each
logistic regression coefficient for Vietnam-era veterans using the Wald P2 statistic. Odds ratios
and confidence intervals for Vietnam-era veterans’ excess risk for suicidality compared to
“other” men of the same age group were also presented. For multivariate logistic regression
analyses, the outcome was completed suicide in the NMFS and lifetime attempted suicide in the
NLAES. The analyses were conducted separately for Vietnam-era veterans and “others.”
Confidence intervals around odds ratios were adjusted with use of the Taylor series method.
Even though the age group of 40 to 60 years old was selected, the age distribution was still
different between Vietnam-era veterans and “other” men and between the two data sets, thus age
by decade was controlled as a covariate in the multivariate analyses. Finer age groups were
determined to be unnecessary based on preliminary analyses. The model fit was assessed by an F
statistic and a C index. The former assesses the extent of the model’s deviation from the null
Suicide Among Vietnam-Era Veterans - 11
hypothesis of no fit; the latter assesses the extent of the model’s predictive power which varies
between 0.5 (under the null hypothesis) and 1.0 (perfect prediction). The magnitude of the
differences in odds ratios of predictors were individually assessed using the estimates of
individual beta coefficients and their standard errors. Additionally, analyses were repeated using
the combined two groups to assess the excess risk of suicidality for Vietnam-era veterans
controlling for other predictors.
RESULTS
Increased risk for suicidality among Vietnam-era veterans
NMFS. The estimated proportion of completed suicides among Vietnam-era veterans
ages 40 to 60 in 1993 is 22.64 per 100,000. The estimated proportion of completed suicides in
the “other” men ages 40 to 60 in 1993 is 20.43 per 100,000. These numbers are based upon the
weighted numbers of suicides in the NMSF data for these two categories and the corresponding
total numbers in the population. While the veteran population did have a slightly higher death
rate (ratio = 1.11), the ratio was not significantly different (95% confidence interval (CI) = 0.64,
1.58). The standard error of the ratio was computed using the delta method (Beers, 1957).
Among the deceased men in the age group of 40 to 60, however, 5.6% of Vietnam-era
veterans’ deaths were due to suicide compared to 2.9% of “other” men’s deaths being due to
suicide (Table 2). The odds ratio (OR) was 1.96 (95% CI = 1.23, 3.12), significant at p < 0.05
level. Based on proxy interviews, 11.1% of Vietnam-era veterans communicated about their
suicidal intent in the last month compared to 4.8% of “others” (OR = 2.50, 95% CI = 0.78, 8.03).
The percentage who expressed morbid thoughts in the last month was 25.5% in Vietnam-era
Suicide Among Vietnam-Era Veterans - 12
veterans compared to 15.3% among “other” men (OR = 1.89, 95% CI = 0.85, 4.20). Neither
measure of non-lethal suicidality was significantly different between the two groups.
NLAES. In the 40 to 60 age group, 2.7% of Vietnam-era veterans reported an attempted
suicide sometime in their lives compared to 1.8% of “other” men (OR = 1.51, 95% CI = 0.95,
2.39). Suicidal ideation was expressed by 10.7% of Vietnam-era veterans compared to 8.4% of
“other” men (OR=1.31, 95% CI = 1.03, 1.66). Morbid thoughts were expressed by 11.0% of
Vietnam-era veterans compared to 9.1% of “other” men. Only the percentage of patients with
suicidal ideation differed significantly between the two groups.
Demographic and behavioral characteristics
In both the NMFS and NLAES data, Vietnam-era veterans compared to “other” men of
the same age group were younger and more likely to have completed high school. In the NLAES
(but not NMFS), Vietnam-era veterans were also significantly more likely to be employed, to
have a DSM-IV diagnosis of alcohol dependence, and to have a history of illicit drug
experimentation. Vietnam-era veterans, however, reported fewer health problems than other men.
Relative importance of risk and protective factors for completed and attempted suicide
NMFS. Results of logistic regression analyses run separately for Vietnam-era veterans
and “other” men ages 40 to 60 are presented in Table 3. The overall model fit indicates the model
contained important predictors for deceased veterans’ suicide (F = 5.07, df = 10, p < .0001).
Among Vietnam-era veterans, deceased African American veterans were only one-fifth as likely
as non-African American veterans to have died by suicide. Those who lived alone were over
three times more likely to die by suicide. Vietnam-era veterans with alcohol problems were
nearly five times as likely to die by suicide as those without alcohol problems. Depression was
Suicide Among Vietnam-Era Veterans - 13
also significantly associated with completed suicide, with depressed Vietnam-era veterans more
than three times as likely to die by suicide as non-depressed Vietnam-era veterans. Health
problems and employment were also significantly associated with completed suicide, but both
were in the opposite direction than expected: employment increased the risk of completed suicide
and health problems were a protective factor for completed suicide. However, the results are
confounded, because most deaths were natural deaths that were positively associated with lack of
employment and health problems, both of which were assessed for the year prior to death.
Predictors of completed suicide among “other” men showed patterns similar to those for
Vietnam-era veterans, with a significant overall model fit (F = 10.68, df = 10, p < .0001). Being
African American was a significant protective factor in that the risk was roughly one-eighth the
risk of non-African Americans. Drug use, even at an experimental level, tripled the risk for
completed suicide as compared with non-drug users. Again, health problems and employment
were significant predictors; however, the results were confounded by a majority of non-suicide
deaths resulting from serious medical illnesses.
NLAES. The overall models are statistically significant for both Vietnam-era veterans
and “other” men (F = 6.05 and F = 10.68 respectively; df = 10, p < .0001 for both). The C index
values of 0.87 and 0.82, respectively, indicate that the predictive power of the NLAES models
was better than in the NMFS models (C = 0.71 for Vietnam-era veterans and C = 0.66 for other
men). Among Vietnam-era veterans, employed veterans were less than half as likely as non-
employed veterans to attempt suicide (association in the expected direction), and married
veterans were significantly less likely to attempt suicide than unmarried veterans. Drug use and
depression were significant risk factors for attempted suicide, placing a veteran at about three and
Suicide Among Vietnam-Era Veterans - 14
half times the risk of non-drug using, or non-depressed veterans. Veterans with health problems
were at about five times the risk of attempting suicide as compared to veterans without such
problems.
Results for “other” men were similar for employment, depression and health problems,
which were all significant predictors in this group. However, being an African American was a
significant protective factor in that the risk for attempted suicide was roughly one-sixth the risk
level for non-African Americans. On the other hand, marital status was not a significant
protective factor. While drug use did not appear to increase risk for attempted suicide
significantly, clinical alcohol dependence increased the odds by almost three times.
Unique predictors among Vietnam-era veterans
The levels of risk for completing suicide shown from the NMFS were significantly
different between Vietnam-era veterans and “other” men for alcohol problems (p = 0.04) and
depression (p = 0.02) (Table 3, 5th column). Those factors are significantly more important risk
factors for completed suicide among Vietnam-era veterans in comparison to risk factors for
“other” men. For NLAES, age uniquely affected the risk of attempted suicide. For Vietnam-era
veterans, being 50 years old or older decreased the risk by more than two-thirds, but age did not
make a difference for other men (p = 0.07) (Table 3, far right column). Additionally, being
married and not having health problems were more important protective factors against suicide
attempt (p = 0.05 and p = 0.06, respectively). However, there were no significant differences in
the levels of risk of attempted suicide for any factor.
Excess risk for Vietnam-era veterans controlling for demographic and behavioral factors
Combining both Vietnam-era veterans and “other” men, deceased Vietnam-veterans were
Suicide Among Vietnam-Era Veterans - 15
found to be 50% (OR = 1.50) more likely to have died from suicide than deceased “other” men,
controlling for the demographic and behavioral factors assessed separately for the two groups
previously. However, the estimate was non-significant (95% CI = 0.87, 2.59). Excess risk for
suicidal attempts for Vietnam-era veterans was 20% (OR = 1.20), and again the estimate was
non-significant (95% CI 0.73, 1.97).
DISCUSSION
Among men 40 to 60 years old in the U.S., deceased Vietnam-era veterans were more
likely to have died from suicide compared to other deceased men of the same age group.
Significant risk factors for completed suicide among Vietnam-era veterans included living alone,
alcohol problems, and depression. The sole significant protective factor was being African
American. The risk for attempted suicide among Vietnam-era veterans, while elevated, was not
significantly different from the risk of “other” men of the same age group. Significant risk factors
for attempted suicide among Vietnam-era veterans included drug use, depression, and health
problems, whereas significant protective factors were being older, employed, and married.
Predictors for completed and attempted suicide among Vietnam-era veterans were similar to
those of “other” men of this age group. However, stronger associations of alcohol problems and
depression with completed suicide were found for Vietnam-era veterans. Marginal differences
were found for age, marital status, and health problems as predictors of attempted suicide
between the two groups. When controlling for risk and protective factors simultaneously,
Vietnam-era veteran status did not significantly increase the risk for suicide and suicide attempts.
The findings are consistent with other studies of male veterans that did not focus on combat
Suicide Among Vietnam-Era Veterans - 16
veterans (e.g., Thoresen, Mehlum, & Moller, 2003).
Employment and health problems in NMFS showed associations with suicide in the
opposite direction than expected. Employment was a risk factor for completed suicide and health
problems was protective against completed suicide. These anomalies are a result of the nature of
the data set. Most of the deceased in the sample died from natural causes. Thus, physical illnesses
leading to unemployment toward the end of life had a stronger association with non-suicidal than
suicide deaths.
Some limitations are inherent in the study of completed suicide and other non-fatal
suicidality. The methodologies for data collection were rather different between the NMFS and
NLAES. To obtain the sample size of Vietnam-era veterans who completed suicide available in
NMFS (estimated n = 27) from a single data set containing both deceased and live subjects, a
survey would have to include about 470,000 live male respondents of this age group at the
baseline to be followed up in the subsequent year, including a search of over 2,800 death
certificates (with a 0.6% death rate). A survey of that scale has never been done in suicide
research, nor is it likely to be conducted in the near future.
The statistically significant finding of the study, an increased risk of completed suicide
among Vietnam-era veterans ages 40 to 60 (OR=1.96; 95% CI = 1.23, 3.12) compared to the
general population of the same age group, needs a cautionary interpretation, because the overall
mortality of the Vietnam-era veterans was likely to be lower than that of “other” men due to a
healthy worker effect. Based on the estimated numbers of suicides in 1993 among men ages 40 to
60, the excess risk of completed suicide among Vietnam-era veterans is estimated to be 16%
higher than that of the of the other men in the general population in the U.S. (but not statistically
Suicide Among Vietnam-Era Veterans - 17
significant). Thus, the significantly elevated risk of death by suicide means not so much that the
absolute number of suicides among Vietnam-era veterans is much higher than the number in the
general population. Rather, Vietnam-era veterans disproportionately died by suicide in 1993 even
though they are generally healthier than the rest of the U.S. male population of this age group.
At issue in suicide deaths are the validity of ICD coding (Moyer, Boyle, & Pollock, 1989)
and multiple versus single causes of death (Tardon, Zaplana, Hernandez, & Cueto, 1995;
Mackenbach, Kunst, Lautenbach, Bijlsma, & Oei, 1995). Such limitations are ameliorated by the
use of mixed methodologies (i.e., death certification, autopsy results, and proxy interview) in the
NMFS. Under-reporting is an issue with the measure of non-fatal suicidality. Research has
shown that as many as 30% of those who commit or attempt suicide (Clark & Fawcett, 1992) and
as many as 50% of depressed individuals who die by suicide (Fawcett et al., 1990) do not report
their suicidal intent. Furthermore, there is some indication that uncommunicated suicide
increases with age (Conwell et al., 1998). Nonetheless, under-reporting of suicidality applies to
almost all suicide research.
Neither the NMFS nor the NLAES included measures on combat and related trauma, or
resultant symptoms of PTSD. Thus, it was not possible to examine increased risks for combat
Vietnam veterans. In the current study, the odds ratio of depression for completed suicide was
3.14 among deceased Vietnam-era veterans compared to 0.88 among other deceased men. It is
possible (and likely) that some symptoms assessed by proxies are surrogates of PTSD symptoms,
or depression was exacerbated by PTSD in this sample. Measures of methods used when
attempting suicide were not available in NLAES, thus suicide lethality measures could not be
included in the analyses. A higher risk of death by suicide among Vietnam-era veterans found in
Suicide Among Vietnam-Era Veterans - 18
this study may in part be due to their greater familiarity with fire arms.
In summary, limited to men in the age group of 40 to 60 years, this study provides good
evidence for a significantly higher proportion of deaths by suicide and inconclusive results for an
elevated risk for attempted suicide among Vietnam-era veterans, compared to the rest of the male
population. However, our results demonstrate that many of the factors that are characteristics of
completed and attempted suicide among Vietnam-era veterans are similar to those for the general
population of middle-aged men. Only a few statistically significant differences were found
between Vietnam-era veterans and “other” men based on the predictors of suicidality available
across the two data sets. The excess risk of completed and attempted suicide among Vietnam-era
veterans, compared to other males of the age group 40 to 60, appears in large part to have
resulted from incremental differences in several demographic and behavioral factors. When these
factors are controlled, Vietnam-era veteran status was not a significant risk factor. Therefore, an
intervention that places an emphasis on the combination of physical, mental health, and
substance abuse problems could be useful in reducing the suicidality risk among aging Vietnam-
era veterans. Consideration should also be given to a similar strategy for the current generation of
young military men serving in global war zones to reduce the risk of their suicide in years to
come.
Suicide Among Vietnam-Era Veterans - 19
ACKNOWLEDGMENTS
This work was supported in part by the Independent Scientist Award (K02DA00221) and
research grant (R01MH60691) to the first author. Editorial assistance by Suzanne Culter and
clerical assistance by Miyuki Ono are both greatly appreciated.
Suicide Among Vietnam-Era Veterans - 20
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TABLE 1
Comparisons of Time Frame and Content of the Measures Between the National Mortality Followback Survey, 1993, and the National
Longitudinal Alcohol Epidemiologic Survey, 1992
NMFSa NLAESb
Time frame Measure content Time frame Measure content
Outcome Past year Completed suicide Lifetimec Attempted suicide
Predictors
Education Time of death No high school diploma Time of interview No high school diploma
Employment Past year Any work at all in the past year Time of interview Employed full-time or part-time
Marital status Time of death Being married Time of interview Being married
Living alone Past year Lived alone Time of interview Living alone
Alcohol
problems
Past year Three or more of alcohol symptoms
related to alcohol dependenced
Lifetime DSM-IV diagnosis of alcohol
dependence
Drug use Past year Any non-prescribed use or overuse of
psychoactive substances, including 11
typese
Lifetime 12 times or more use of illicit drug,
including eight types of psychoactive
substancese
Depression Past year Four or more symptoms suggestive of
clinical major depressionf
Lifetime DSM-IV diagnosis of major
depression excluding the symptom of
suicidality
Health
problems
Lifetime Two or more major health problemsg Lifetime Two or more major health problemsg
Note. Age and race measures are identical across the two surveys.
a The National Mortality Followback Survey, 1993.
b The National Longitudinal Alcohol Epidemiologic Survey, 1992.
c The combined measure includes lifetime assessment of attempted suicide conditioned on depressive mode and/or attempted suicide
in past year without report of depressive mode.
d Available symptoms include frequent drinking, spending a lot of time drunk or hungover, failure to cut down, annoyed by criticism
of drinking, felt guilty about drinking, morning drinking, or advised by a doctor to stop or decrease drinking.
e For NMFS, substances include antidepressants, cocaine, hallucinogens, heroin, marijuana, methadone, pain killers, sedatives,
steroids, stimulants, or tranquilizers; for NLAES, substances include cocaine, heroin, marijuana, methadone, pain killers, sedatives,
stimulants, tranquilizers, and others.
f Available symptoms include change in appetite, drowsy or sluggish, feelings of guilt, having trouble concentrating, long periods of
crying, trouble sleeping, and being withdrawn.
g For NMFS, health problems include Alzheimer’s, cancer, cirrhosis, diabetes, emphysema, and stroke; for NLAES, problems include
arthritis, cancer, cirrhosis, diabetes, epilepsy, emphysema, heart attack, high blood pressure, hepatitis, and stroke.
TABLE 2
Demographic and Behavioral Characteristics of Men 40-60 Years Old in the National Mortality Followback Survey and the National
Longitudinal Alcohol Epidemiologic Survey
NMFSa NLAESb
Vietnam-era
veteran
(n = 494)
Other
(n = 2,331)
Vietnam-era
veteran
(n = 1,277)
Other
(n = 4,185)
Suicidality
Completed suicide (%) 5.6* 2.9* ... ...
Attempted suicide (%) ... ... 2.7 1.8
Communication of suicide intent (%) 11.1 4.8 ... ...
Suicidal ideation (%) ... ... 10.7* 8.4*
Morbid thought (%) 25.5 15.3 11.0 9.1
Demographic
Age (% 50 years old or older) 39.8* 68.9* 19.3* 46.4*
Race (% African American) 21.8 19.2 9.5 9.7
Education (% no high school diploma) 20.7* 38.7* 6.5* 18.0*
Employment (% employed) 48.3 42.5 86.2* 83.1*
Marital status (% currently married) 54.4 53.9 79.7 81.0
Behavioral
Living alone (%) 16.2 20.1 10.9 10.5
Alcohol problems (%)c 35.6 30.0 23.6* 17.4*
Drug use (%)c 10.9 6.4 21.8* 12.3*
Depression (%)c 29.3 30.5 9.1 7.6
Health problems (%)c 23.6 31.9 13.3* 16.2*
Note. The percentages are shown separately for Vietnam-era veterans and others. They are weighted with standard errors adjusted by
the SUDAAN Taylor series method. * indicates p < .05 based on using the Wald P2 statistic testing an unadjusted logistic regression
coefficient for Vietnam-era veterans compared to “others” (two-tail test).
a The National Mortality Followback Survey, 1993, men aged 40 to 60 years old at the time of death.
b The National Longitudinal Alcohol Epidemiologic Survey, 1992, men aged 40 to 60 years old at the time of interview.
c See Table 1 for a description of each of the four behavioral measures.
TABLE 3
Comparing the Relative Magnitude of Associations of Predictors for Suicide and Suicide Attempt Between Vietnam-Era Veterans and
Other Males of Ages 40 to 60 Years Old
NMFSa (outcome = completed suicide) NLAESb (outcome = attempted suicide)
Predictors
Vietnam-era
veteran
(n = 494)
Other
(n = 2,331) p-value for
differences
of beta
coefficients
Vietnam-era
veteran
( n = 1,277)
Other
(n = 4,185) p-value for
differences
of beta
coefficientsOR 95% CI OR 95% CI OR 95% CI OR 95% CI
Age (50 years or older) 0.54 0.20, 1.50 0.60 0.38, 0.96 0.86 0.26* 0.07, 0.95 0.93 0.54, 1.59 0.07
Race (African
American) 0.20* 0.06, 0.66 0.12* 0.06, 0.22 0.47 0.57 0.17, 1.87 0.16* 0.05, 0.57
0.15
Education (no high
school diploma) 0.53 0.15, 1.78 1.43 0.87, 2.36 0.14 1.01 1.28, 3.58 1.23 0.53, 2.85 0.79
Employment (currently
employed) 3.98* 1.42, 11.11 2.01* 1.24, 3.25 0.24 0.43* 0.20, 0.93 0.40* 0.21, 0.75 0.86
Marital status
(currently married) 1.94 0.67, 5.64 1.02 0.57, 1.81 0.30 0.18* 0.05, 0.64 0.72 0.37, 1.38 0.05
Living alone 3.42* 1.16, 10.09 1.42 0.78, 2.57 0.16 0.59 0.17, 2.10 1.04 0.52, 2.07 0.44
Alcohol problemc 4.90* 2.04, 11.76 1.69 1.03, 2.78 0.04 2.05 0.79, 5.33 2.94* 1.68, 5.17 0.51
Drug usec 2.13 0.74, 6.15 3.01* 1.45, 6.26 0.60 3.55* 1.42, 8.86 1.64 0.90, 2.99 0.16
Depressionc 3.14* 1.23, 7.98 0.88 0.49-1.58 0.02 3.78* 1.65, 8.65 4.23* 2.29, 7.81 0.83
Health problemsc 0.10* 0.02, 0.51 .25* 0.14, 0.46 0.29 4.93* 2.12, 11.44 1.90* 1.08, 3.32 0.06
Model fitd F = 5.07
C = 0.71
F = 10.68
C = 0.66
F = 6.05
C = 0.87
F = 10.68
C = 0.82
Note. The adjusted odds ratios (OR) and 95% confidence intervals (CI) are shown separately for Vietnam-era veterans and “others.”
They are weighted with standard errors adjusted by the SUDAAN Taylor series method. * indicates p < .05 for the regression
coefficient for individual logistic regression. A p-value listed in the last column for each data set is the significance level of the t-value
for the difference of two regression coefficients between Vietnam-era veterans and “others” (two-tail test).
a The National Mortality Followback Survey, 1993, men aged 40 to 60 years old at the time of death.
b The National Longitudinal Alcohol Epidemiologic Survey, 1992, men aged 40 to 60 years old at the time of interview.
c See Table 1 for a description of each of the four behavioral measures.
d df = 10, p < 0.0001 for all F statistics. The C index varies from 0.5 under the null hypothesis to the maximum 1.00.
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