Malingering? No Evidence in a Predominantly Hispanic Workers' Compensation Population with Chronic Pain

Sample 

We purposefully sampled medical records from 1995 to 2005 and included all records of patients with a history of pain ≥3 months and a full psychologic evaluation. Patients had a variety of medical diagnoses, including: physical trauma from motor vehicle or heavy machinery; joint, upper/lower extremity, or back pain; median, ulnar, or brachial plexus neuropathy; and other neuralgia, neuritis, radiculitis, and musculoskeletal symptoms. About 57% had received surgical treatment to correct the underlying cause of their pain but continued to experience unrelenting persistent pain. The same psychologist conducted all evaluations using the Oswestry Pain Questionnaire (Oswestry), Psychosocial Stressors Severity (PSS), Patient Problem Report (PPR), and the Global Assessment of Function (GAF). All patients received standard treatment for underlying medical condition, psychologic support, and pain management. Pain management incorporated a signed contract, a prescription for return to work, exercise, weight management, and medications as indicated, such as analgesics, adjuvants (antidepressants, sleep aids, etc.), and neuroleptic medications. In addition, the physician provided compassionate patient-centered care, spending 30 minutes or more providing education and guidance, emotional support, and active listening at the majority of visits.

Data Collection Methods 

From October through December 2006, we extracted, coded, cleaned, and imported data into a computer statistical program (SAS version 9.1) for analysis by a university statistician. We ensured intercoder reliability by periodically confirming extracted and coded dated with the research assistant trained to extract and code data.

Demographic data were extracted from the primary medical record or the psychologist report, or both, and included gender, marital status, education, occupation, and ethnicity. Measured outcomes included: pain severity; malingering and psychologic distress, such as depression, suicidal ideation, and substance use or abuse; work and litigation status; and level of functioning assessed by Oswestry, PSS, PPR, and GAF as documented by the psychologist (Table 1).

Table 1. Measured Outcomes

	Outcome	Type of Measure	Frequency	Reported Reliability & Validity
	Pain severity	Equidistant 0-10 numeric rating scale (from no pain to worst pain possible)	Psychologist visit Each clinic visit	McQuay & Moore (2006, p. 416)
	Malingering	Psychiatric diagnosis based on DSM criteria	Psychologist visit
	Return to work (RTW)	Self-report	Psychologist visit Each clinic visit
	Litigation status	Self-report	Psychologist visit
	Functioning
	Oswestry Pain Questionnaire—indicator of how pain affects an individual's ability to manage everyday life	10-item survey that allows individuals to rate overall intensity of pain and impact of pain on personal care, lifting, walking, sitting, standing, sleeping, sex life, social life, and travel Items measured using 0-5 Likert rating scale, with 0 indicating no limitation due to pain and 5 noting maximum limitation; the total score ranges from 0-50; when doubled it converts into a disability rating	Psychologist visit	Rocchi, Sisti, Benedetti, et al. (2005)
	Patient Problem Report (PPR)—rating of 18 psychosocial and environmental problems during the year before the onset of chronic pain and since the onset of chronic pain	Each item rated on a 4-point Likert scale from no problem to extreme problem. Items include work, interpersonal relationships, general and social activities, finances, drug and alcohol use, self-esteem, physical and emotional health, suicidal impulses, social support, and health care	Psychologist visit	APA (2000) Skodol (1991) Skodol & Shrout (1989)
	Psychosocial Stressors Severity (PSS)—rating of the impact of psychosocial and environmental stressors on factors that affect or are affected by the diagnosis, treatment, and prognosis of psychiatric illnesses	One-item 3-point Likert scale that rates the PSS as mild, moderate, or severe; rating determined by difference in PSS before and after chronic pain	Psychologist visit	APA (2000) Skodol (1991) Skodol & Shrout (1989)
	Global Assessment of Function (GAF) scale—rating overall psychologic, social, and occupational functioning of people ≥18 years of age	100-point measurement broken into 20-point increments. Each 10-point range has two components: one for symptom severity and one for functioning; when symptoms and functioning are discordant, the rating reflects the worse of the two; higher ratings reflect higher levels of functioning	Psychologist visit	APA (2000) Endicott et. al (1976) Goldman, Skodol, & Helmick (1992)

Analysis 

The analyses consisted of descriptive statistics, Pearson correlations, multiple regression, and chi-square. Upon request, the statistician calculated odds ratio to quantify the relationships between high-interest categorical variables, such as gender, ethnicity, litigation status, and education with work status at the time of the last follow-up visit with the surgeon. We calculated both a priori and post hoc power analyses for a medium effect size, power of .80, and alpha of .05. Based on a priori analysis, data from 85 medical records were needed to meet correlational significance (Cohen, 1992). Post hoc power analysis indicated that a sample size of 67 and 87 were necessary to reach statistical significance for multiple regression and chi-square measurements, respectively.

Demographic Data and Pain Level 

The sample (n = 91) closely reflects the population of the U.S.-Mexico border city where the clinic practice is located. The majority were Hispanic (81.3%), female (70.3%), and married (60.44%). Educational level was more-or-less evenly split into three groups: grade school or less, high school, and college or post–high school training. Eighty-seven (93%) were workers' compensation patients and one-third were litigating for compensation related to work-related or other injury (Table 2). At the time of the first visit to the psychologist, the typical patient was 42.6 years old experiencing high levels of daily pain (7/10) for 3.5 years. Average follow-up time by the surgeon after psychological evaluation was 2 years (Table 3).

Table 2. Demographic Data

		n	%
	Gender (n = 91)
	Female	64	70.33
	Male	27	29.67
	Ethnicity (n = 91)
	Non-Hispanic	17	18.68
	Hispanic	74	81.32
	Education (n = 91)
	Grade school and less	28	30.77
	High school	29	31.87
	Post–high school/college	34	37.36
	Marital status (n = 91)
	Married	55	60.44
	Not married	36	39.56
	Litigation status (n = 90)
	No	60	66.66
	Yes	30	33.33

Table 3. Age and Pain Severity

		Age, yrs	Pain duration, psychologist visit, yrs	Pain duration, last FU visit by surgeon, yrs	FU by surgeon after psych evaluation, yrs	Pain level, initial visit	Pain level, usual psych visit	Pain level, least psych visit	Pain level, worst psych visit
	n	91	91	91	90	89	89	89	89
	Mean	42.64	3.46	5.76	2.43	7.49	7.04	5.02	9.15
	Median	42	3	5	2	8	7	5	9
	Mode	43	1	4	2	8	7	5	10
	SD	10.05	3.57	4.2	2.03	2.27	1.54	2.06	1.05
	Range	17-70	0.08-22	0.5-23	0-10	2-10	3-10	0-10	5-10

FU = follow-up.

Malingering and Psychological Distress 

No participant received a diagnosis of malingering by the psychologist; nor did anyone receive a diagnosis of chronic pain syndrome, i.e., pain disorder associated with psychologic factors, a condition that attributes pain to psychosocial stressors with little or no underlying medical condition (APA, 2000, p. 499). Nonetheless, the participants experienced extreme distress in terms of mood and function. Over 92% of patients (83 out of 90) had mood disorders, with the majority (70 out of 83) documented as secondary to chronic pain. Of the remaining seven patients with primary psychiatric diagnoses, one was diagnosed with conversion disorder and the others with adjustment disorders all related to pain. The psychologic distress due to chronic pain was severe enough that about one-third of patients (32.3%, 29 out of 90) reported thoughts of self-harm, suicidal ideation, or suicide attempt (Table 4). Despite the high rate of suicidal ideation, we found no documentation of suicide in the medical records of this population, nor were any records omitted because of this.

Table 4. Suicidal Ideation and Substance Use as Documented by Psychologist

		n	%
	Suicidal thoughts (n = 90)
	None	61	67.78
	Thoughts of self-harm	6	6.67
	Suicide ideation	14	15.56
	Suicide attempt	9	10.00
	Alcohol use (n = 91)
	None	64	70.33
	Slight	19	20.88
	Social drinker	2	2.20
	Moderate	6	6.59
	Tobacco use (n = 90)
	None	66	72.53
	Slight	9	9.89
	Moderate	10	10.99
	Heavy	6	6.59

Per the psychologist report, all patients denied illicit drug use, and the majority denied alcohol (64 out of 91) and tobacco (66 out of 91) use. According to the PPR, out of 88 individuals, 83 reported no problem, three a mild problem, one a moderate problem, and one a severe problem with alcohol, and no one reported problems with drug use before the onset of pain. There was no difference in the number of individuals reporting problems with alcohol and drug use after pain incident (Table 4).

Work Status and Litigation 

Work was defined as employment, retirement, or returning to school or retraining as a student. Six individuals (6.6%) reported not working before the onset of chronic pain. At the time of the psychologist visit, about 64% (58 out of 91) were not working, and the number of students increased from one to five. At the last follow-up visit with the physician, the number of unemployed patients (six, 6.6%) was no different from the number of nonworkers before onset of chronic pain. However, the persons not working at the last follow-up visit were not necessarily those individuals who were not working at the initial visit to the surgeon. At the last follow-up visit by the surgeon seven individuals (7.7%) were classified as disabled based on Social Security criteria (Table 5).

Table 5. Work Status at Three Different Time Periods

		Not Working	Working	Retired	Student	Disabled
	Before pain/injury	6 (6.6%)	81 (89%)	3 (3.3%)	1 (1.1%)	na
	Time of psychologist visit	58 (63.7%)	25 (27.5%)	3 (3.3%)	5 (5.5%)	na
	Time of last follow-up visit with surgeon	6 (6.6%)	72 (79.1%)	5 (5.5%)	1 (1.1%)	7 (7.7%)

Functioning 

The psychologist documented Psychosocial Stressors Severity (PSS) scores for 86 and Global Assessment of Function (GAF) for 87 patients. Almost 84% reported that stressors severely affected their health. Likewise, the majority of individuals experienced pain and other psychosocial symptoms that led to moderate (57.5%) or serious (27.6%) difficulty in social, occupational, or school functioning (See Table 6). The areas of the PPR that patients reported most problematic were emotions, social relationships and activity, finances, physical health, self-esteem, and support (p > .001).

Table 6. Stressors and Function

		n	%
	Psychosocial Stressors Severity (n = 86)
	Mild	1.16	1
	Moderate	15.12	14
	Severe	83.72	86
	Global Assessment of Function∗ (n = 87)
	Serious difficulty (41-50)	24	27.59
	Moderate difficulty (51-60)	50	57.47
	Some difficulty (61-70)	12	13.79
	Good in all areas (71-80)	1	1.15

∗ Ranking for social, occupational, or school functioning.

Correlations and Differences 

Gender, ethnicity, age, education, litigation status, or total PPR scores in the year before the onset of the chronic pain condition were not significantly associated with work status, level of pain, or GAF scores. Likewise, there was no statistical difference in work status at the time of the last follow-up visit with the physician based on gender, ethnicity, marital status, level of education, or report of litigation for compensation. However, function using GAF total scores, was negatively correlated with total Oswestry scores (−0.3455; p = .0014), usual pain level (−0.221; p = .0411), and total PPR at time of psychologist visit (−5,318; p > .0001). In other words, as reported pain severity and impact of pain on psychological, emotional, social, and physical health (Oswestry and PPR) increased, general interpersonal, social, and occupational function (GAF) declined (Table 7). To quantify the relationships between high-interest categorical variables with work status on follow-up, the statistician calculated odds ratio for each pair. Odds ratio for return to work indicated no difference based on age, gender, ethnicity, duration of pain, or litigation status (Table 8).

Table 7. Maximum Likelihood Estimates for Work Status at Last Visit with Surgeon (n = 91)

	Parameter	df	Estimate	Standard Error	Wald chi-squared	Pr > χ2
	Gender	1	0.1430	0.3446	0.1723	0.6781
	Ethnicity	1	−0.3618	0.4479	0.6527	0.4192
	Education: grade school and less	1	0.2063	0.5499	0.1408	0.7075
	Education: high school	1	−0.9239	0.6749	1.8744	0.1710
	Education: post high school/college	1	0.5599	0.6186	0.8191	0.3654
	Marital status	1	0.1819	0.3525	0.2663	0.6058
	Litigation status	1	0.1645	0.3452	0.2272	0.6336

Table 8. Odds Ratio Estimates for Return to Work Status at Time of Last Visit

	Effect	Point Estimate	95% Wald Confidence Limits
	Gender	1.331	0.345	5.139
	Ethnicity	0.485	0.0084	2.807
	Litigation	1.390	0.359	5.378
	Marital status	1.439	0.361	5.726
	Age	0.939	0.871	1.012
	Duration of pain	0.901	0.168	4.839
	Length of foloow-up	1.014	0.195	5.279

Limitations 

Like all archival research, the design of this study is limited by the lack of control over data that were available. We have no record of the number of patients referred to the psychologist who did not go or who went but did not return to us for follow-up. Over a period of ten years, the practice of medicine and psychology changed, as did reporting methods. Therefore, our access was limited to the psychologic testing that remained consistent over ten years. Conversely, the same physician and psychologist conducted the assessments over the same time period, lending some uniformity to evaluation and treatment.