Table 1 Characteristics of studies that have investigated the association between deployment to the Gulf War and symptoms of pain amongst veterans
From: Pain in veterans of the Gulf War of 1991: a systematic review
Study | Sample | Study design | Measured outcomes | Response rate and bias | Confounding | Notes |
|---|---|---|---|---|---|---|
Sutker 1993 | 215 GWV 44 NGV Sampled from 5 National Guard and Army Reserve units as part of debriefing programme | Questionnaire administered by VA staff 4–10 months after return from Operation Desert Shield/Storm | General aches and pains as measured by the Health symptom checklists | 70% GWV response (306 eligible) 91 GWV excluded from analysis for failure to complete the majority of measures administered, however, they 'did not differ on descriptive variables' from those that were analysed. Number of eligible NGVs unclear | Bonferonni adjustment showed no sig. effects for sex/race although women and non-white participants tended to report more health complaints | Symptom presence included the report of the symptom at least once a week over the past 30 days |
Sostek 1996 | 57 GWV 44 NGV members of a single National Guard Unit | Questionnaire survey | Joint pain Abdominal pain (infra or supra umbilical location) | 62% GWV (92 sampled) 100% NGV (44 sampled) Unclear what percentage of the unit was sampled | No adjustments were made for confounding. Groups were said to be similar on a range of socio-demographic variables with the exception of age. Gulf veterans were significantly older. | Authors suggest that bias may be present in their study as a significantly higher proportion (p≤0.05) of Gulf veterans report experiencing a 'change in the colour of fingernails' (a control symptom) |
Iowa 1997 | 1896 GWV 1799 NGV DoD Manpower Data Center used to create a stratified random sample from 28,968 military personnel from Iowa | Cross-sectional telephone interview survey Sept 1995 – May 1996 | Bodily pain | 78% GWV (2421 eligible) 73% NGV (2465 eligible) Those who were regulars, enlisted, navy or coast guard, aged up to 25 years and black or other ethnic background less likely to participate | Controlled for stratification variables: military service (regular/National Guard), age, sex, race, branch of service and rank | Response reliability for 165 interviews kappa 0.39–0.79 |
Doebbeling 2000 | see Iowa 1997 | see Iowa 1997 | Pain or aches in more than 1 joint Back pain | see Iowa 1997 | see Iowa 1997 | |
Voelker 2002 | See Iowa 1997 | see IOWA 1997 | Bodily pain on SF-36 | see Iowa 1997 | See Iowa 1997 | Effect size is the standardised mean difference on the bodily pain subscale of the SF36 |
Peloso 2002 | See Iowa 1997 | See Iowa 1997 | Chronic widespread pain | See Iowa 1997 | See Iowa 1997 | Outcome – pain present in last year and last month, moderate or greater severity and involvement of upper and lower extremities and trunk |
Fukuda 1998 | 1163 GWV 2538 NGV Sampled veterans were active duty members of the Air Force, from Florida or Pennsylvania and who were on base at the time of the survey | Cross-sectional population survey Jan – March 1995 | Joint pain Muscle pain Chest pain | Veterans were not sampled according to Gulf status so no differential response rates are given. Unit response rate 35% – 73% | No report of adjustment made for potential confounders. | |
Goss Gilroy 1998 | 3113 Canadian GWV 3439 Canadian NGV Sampled from Department of National Defence human resources data files | Cross-sectional survey | Serious trouble with back pain | 73% GWV (4262 eligible) 60% NGV (5699 eligible) | NGVs matched on sex, age group and regular/reserve status | Only data for male veterans is presented. |
Proctor 1998 | 186 GWV from Fort Devens 66 GWV from New Orleans 48 Germany deployed veterans | Cohort study Spring 1994 – Autumn 1996 | Joint pain Chest pain | 53% Fort Devens (353 sampled, 2949 eligible) 34% New Orleans (194 sampled, 928 eligible) 51% Germany deployed. Participants were recruited after taking part in a previous study | Published odds ratios were weighted for sampling design and adjusted for age, sex and education | |
Proctor 2001 | See Proctor 1998 | See Proctor 1998 | Chronic back pain Bodily pain on SF-36 | See Proctor 1998 | See Proctor 1998 | |
Ishoy 1999 | 686 GWV 231 NGV Selected from Danish Armed Forces personnel database | Cross-sectional survey Feb 1997-Jan 1998 | Joint pain Muscle pain | 84% GWV (821 eligible) 58% NDV (400 sampled) Non-response meant GWV more likely to be older males | Controls matched for gender, age and profession | |
Unwin 1999 | 3284 GWV 1815 Bosnia veterans 2408 Era controls Random sample taken from the UK MoD database Service men only | Cross-sectional postal survey August 1997-Nov 1998 | Pain without redness or swelling in several joints Chest pain | 70% GWV (4250 eligible) 62% Bosnia (4250 eligible) 63% Era (4246 eligible) Responders were significantly older and more likely to be in service but didn't differ on SF36 ratings | Sample was stratified by service, status, sex, age, rank and fitness. Analyses restricted to male veterans. Potential confounders (age, marital status, rank, education, employment, still serving or discharged, smoking, alcohol consumption and GHQ score) are adjusted for by logistic regression | |
Unwin 2002 | 236 GWV 217 Bosnia veterans 192 Era controls Service women only | See Unwin 1999 | Pain without redness or swelling in several joints | 72% GWV 66% Bosnia 58% Era | Analyses restricted to female veterans. | |
Kang 2000 | 11441 GWV 9476 NGV Stratified random sample taken from the DoD Manpower Data Center | Population based survey 1995–1997 | Joint pain Muscle pain Back pain Abdominal pain | 76% GWV (15000 eligible) 63% NGV (15000 eligible) Non responders were more likely to be younger, unmarried, non-white and enlisted | Estimates were weighted to control for stratification variables: gender and unit component | |
Knoke 2000 | 524 GWV 935 NGV Sampled from active duty US Naval mobile construction battalion personnel (Seabees). Personnel had to be in residence at either Port Hueneme or Gulfport | Questionnaire survey carried out in 1994 | Pains in lower back Pains in heart/chest Moving joint pain Unusual muscle pain Chest pain Abdominal pain Earlobe pain | 65% GWV 46% NGV | Analyses restricted to male veterans. | 'Earlobe pain' was included as a validity symptom as it was thought not to have a physiologic basis |
Steele 2000 | 1435 GWV 409 NGV DoD Manpower Data Center used to create a stratified random sample from 16,566 military personnel from Kansas | Population based telephone survey Feb – Aug 1998 | Joint pain Muscle pain Body pain (hurts all over) Abdominal pain or cramping Moderate/multiple pain symptoms | 65% response (3138 eligible) Overall, Gulf and female veterans were more likely to respond. | Published odds ratios are adjusted for sex, age, income level and education level. | Women and reservists deliberately over sampled due to increased reporting of ill health in those groups. Veterans had to be either separated or retired from military or currently serving in the reserves. |
Cherry 2001 | 8210 GWV 3981 NGV Random sample taken from the UK MoD database | Cross-sectional survey Dec 1997-Sept 1999 | Stomach pain Pain in your chest Widespread pain | 86% GWV (9505 eligible) 84% NGV (4749 eligible) Non responders were younger | NGV sample stratified by sex, age, service and rank to frequency match GWV sample. | Widespread pain defined as "axial skeletal and contra lateral body pain" for at least 24 hours in the past month |
Gray 2002 | 3831 GWV 4933 deployed elsewhere 3104 non-deployed All active duty Seabees regardless of whether still in service at time of study identified through Defense Manpower Data Center | Cross-sectional survey May 1997 – May 1999 | Unusual muscle pain Joint pain Chest pain Stomach pain/ulcer | Total eligible 18,945 64% response Respondents more likely to be reservists, married, Caucasian, and deployed elsewhere. | Published odds ratios adjusted for age, gender, active-duty/reserve status, ethnicity, smoking, alcohol use. | Reliability for self-reported physician-diagnosed medical conditions in 519 subjects retested 6 months apart: Kappa = 0.6 |
Simmons 2004 | 23,358 GWV 17,730 NGV Stratified random sample from UK MoD database | Cross-sectional postal survey Aug 1998-March 2001 | Muscular pain/weakness Chest pains/tightness | 48% response overall. Pain data available for: 45% GWV (51581 eligible) 34% NGV (51688 eligible) | Analysis restricted to male veterans. Published odds ratios adjusted for age, service, rank, service status at time of survey, alcohol and smoking | |
Kelsall 2004 | 1456 GWV 1588 NGV Stratified random sample from Australian Defence Force database | Cross-sectional postal survey Aug 2000-April 2002 | General muscle pain Pain without redness or swelling in several joints Low back pain | 78% GWV (1871 eligible) 54% NGV (2924 eligible) Non responders were younger and of lower rank. | Analyses restricted to male veterans. Published odds ratios adjusted for sex, 3 yr age band, service and rank. |