Am. J. Respir. Crit. Care Med., Volume 163, Number 2, February 2001, 329-334
Department of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland; Pulmonary and Critical Care Medicine, University of Cincinnati, Cincinnati, Ohio; Division of Pulmonary and Critical Care Medicine, Medical University of South Carolina, Charleston, South Carolina; Division of Pulmonary and Critical Care Medicine, Georgetown University, Washington, DC; Division of Pulmonary and Critical Care Medicine, Mount Sinai Medical Center, New York, New York; and Pulmonary and Critical Care Division, University of Pennsylvania, Philadelphia, Pennsylvania
| ABSTRACT |
|---|
Sarcoidosis, a chronic, multisystem disease, impacts quality of life and may increase depression risk. No previous study has reported the depression prevalence among U.S. Sarcoid patients. This cross-sectional study examined sociodemographic and disease morbidity factors associated with depression. Patients diagnosed for <1 yr and treated at one of six centers were eligible (n = 176); 154 completed a questionnaire of demographics, treatment, access to medical care, and a short-form Center for Epidemiologic Studies Depression Scale (CES-D). The primary outcome variable was a CES-D score of >= 9, indicating clinical depression. The prevalence of depression was 60%. Gender, income, access to medical care, dyspnea on exertion, and number of systems involved were associated with depression. Female sex, decreased access to medical care, and increased dyspnea predicted depression (odds ratio [OR] = 3.33, 11.64, and 2.78, respectively) after adjusting for race, income, and steroid therapy. Despite tertiary care access, patients reported medical care limitation. Health care providers must be sensitive to multiple barriers faced by chronic Sarcoid patients; acknowledging depression risk and improving access to medical care will promote better overall health among Sarcoid patients. Future studies of Sarcoidosis will need to address depression diagnosis and treatment.
| INTRODUCTION |
|---|
Sarcoidosis is a granulomatous disease that typically affects people in the most productive years of their lives with a peak incidence in the third to fifth decades (1). The United States age-adjusted annual prevalence for whites is 10-12/100,000 and for African-Americans, 30-39/100,000 (2); studies done in the United States show that African-American race predicts a more severe prognosis with worse pulmonary disease than white race (1). The burden of chronic Sarcoidosis includes such symptoms as fatigue, night sweats, dyspnea, cough, and chest pain. Chronicillnesses such as Sarcoidosis not only place physical demands on patients but emotional burdens as well (4). To date the only known study of depression in Sarcoidosis, conducted in the Netherlands, showed a high prevalence of depression even after adjusting for severity of disease, demographic factors, and cognitive style (7). However, because the Netherlands Sarcoid population is 99.5% white implying less severe disease (8) and the country has uniform health care coverage implying better access to health care, these results may not generalize to the U.S. population. Sarcoid patients in the United States are predominately African-American and studies have shown that African-Americans are more likelyto be below the poverty line and are disproportionately at risk for access limitations to medical care (9). This study examined the prevalence and predictors of depression, including race, sex, income, and access to care, in a diverse sample of U.S. patients with chronic Sarcoidosis.
| METHODS |
|---|
Patient Population
From August 1996 to August 1997 patients with Sarcoidosis were recruited from Sarcoid clinics at six participating centers: Georgetown University, Washington, DC; Johns Hopkins Hospital, Baltimore, Maryland; Medical University of South Carolina, Charleston, South Carolina; Mount Sinai Medical Center, New York City, New York; University of Cincinnati Medical Center, Cincinnati, Ohio;and University of Pennsylvania, Philadelphia, Pennsylvania. All six centers are tertiary care referral centers for Sarcoidosis. Eligible patients were 18 yr of age or older and had a diagnosis of Sarcoidosis for greater than 1 yr. All clinic patients seen during the recruitment period were screened for eligibility. Of 175 consecutive patients who met these criteria, 18 patients refused to participate, three patient records were incomplete, leaving 154 patients who agreed to participate and completed the study.
Data Collection
Eligible subjects were asked to participate in the study during a routine clinic appointment. After informed consent was obtained, the patients completed a questionnaire during this visit in a quiet, private setting. For patients with vision, literacy, or language problems, the coordinator read the questionnaire to the patient. The examining physician or research staff completed a second medical questionnaire. Site study coordinators reviewed all questionnaires and forms for completeness and sent them to the coordinating center at the Johns Hopkins Asthma and Allergy Center.
Measures
The patient questionnaire included items assessing patient race, sex, income, and access to medical care. A modified short-form of the Center for Epidemiologic Studies Depression Scale (CES-D) was used to measure depression. The examining physicians and site study coordinators ascertained the symptoms and medical history using a standardized protocol.
Total Health Access Scale
We developed a summary Total Health Access (THA) Scale to measure the patient's overall access to medical care. The THA Scale is a scale of five yes/no questions that assess limitations in access to both physicians and medications (Figure 1). Responses were rated and summed to create a Total Health Access Scale score ranging from 5 representing no reported limitation to health care to zero representing limitation in all areas. The mean standardizeditem Cronbach alpha for this scale was 0.78 indicating good inter-item reliability.
Center for Epidemiologic Studies Depression Scale
The CES-D scale is a simple self-report measure that has been widely used to measure depression in both clinical and community based studies (10, 11). The CES-D has been found to have high internal consistency (r = 0.85), acceptable test-retest stability (r = 0.53), good concurrent validity by clinical criteria (r = 0.54 to 0.75 with Raskin Rating Scale; r = 0.56 with clinical depression severity rating), and excellent concurrent validity by self-report criteria (r = 0.83 with Symptom Check List-90) (10). The full CES-D has 20 items; a score of 16 and higher indicates depression. Several shortened forms of the CES-D have been shown to have excellent comparability to the full 20-item scale with good reliability and validity. For brevity purposes, we shortened the CES-D to 11 questions (Appendix ) selected to reflect depressive affect, positive affect, and somatic symptoms. The Cronbach alpha for this 11-item scale was 0.83 indicating good inter-item reliability.
The CES-D responses rated the frequency of symptoms in the past week on a four-point scale from ''rarely'' (less than 1 d a week) to ''most of the time'' (nearly every day). Positively worded items were reverse scored compared with the negatively worded ones; the items were then added up for a composite score. If the patient answered fewer than 9 items, a CES-D score was not calculated. If items were missing, the sum of the completed items was divided by the proportion of the answered items to calculate a final CES-Dscore. A score of 9 was used to indicate depression (slightly more stringent than the proportional score of 16 for the 20-question CES-D).
Medical Questionnaire
The examining physicians and the study coordinators completed the medical questionnaires based on the patient encounter and the medical record. Information regarding the presence of current symptoms, history, physical exam, treatment, and recent chest X-ray was included. These were completed during the patient's visit; a review of the medical record was used for missing information.
Statistical Analysis
Statistical analyses of demographic, medical, and psychological factors used the chi2 and Fisher exact tests for categorical data and t test for continuous data. Wilcoxon rank-sum test for trends was used with the CES-D scores as the dependent variable. Logistic regression was used to analyze which baseline variables were significantly related to depression. Candidate variables for regression analysis were chosen to reflect the following patient domains: demographics (race and sex), socioeconomics (median income and THA scale),and disease severity (dyspnea on exertion and steroid therapy). Because of small sample number, races other than African-American and white were not included in the multivariate analysis. Because two of the THA questions referred to the cost of health care, reporting zero to two limitations were grouped together. Analyses were performed using Stata Statistical Software (Release 6.0; Stata, College Station, TX).
| RESULTS |
|---|
Patient Demographics
A total of 154 patients completed the survey 136 on their own and 18 with assistance (Table 1); those requiring assistance were not statistically different from those who did not. The mean age was 47 yr; there were 121 women and 33 men. In 1997, the mean poverty level was just above $16,000 in the United States; in our study population, 44% fell below that level. In addition, 30% had Medicaid or other public insurance plan, and 10% were without insurance.
In the United States, Sarcoidosis affects predominately African-Americans and women. African-Americans comprised 71% of our study patients; they were twice as likely to be single than non-African-Americans, but there were no age or sex differences. African-Americans were three times more likely to fall below the poverty level compared with non-African-Americans (p < 0.01) and were twice as likely to possess Medicaid, other public health plan, or no insurance (p = 0.01). African-American patients carried the diagnosis ofSarcoidosis nearly twice as long as non-African-Americans (11.2 versus 6.4 yr; p < 0.01). Sixty-nine percent of female and 82% of male patients were African-American. Forty percent of the female patients had private insurance compared with 27% of men; and only 9% had no insurance versus 15% of men. There were no statistically significant differences between male and female patients in age, income, or education.
Disease Morbidity
Sarcoid diagnosis was made by tissue in 85% of patients, by Kveim in 4%, and by Lofgren's syndrome (fever, polyarthritis, bilateral hilar adenopathy, and erythema nodosum) in 2%; the remaining 10% had a clinical presentation and course compatible with Sarcoidosis. There were no clinically significant, statistical differences between those diagnosed by tissue and those diagnosed by other means. Ninety-five percent of the patients were symptomatic at the time of the study. The most commonly reported symptoms were dyspnea on exertion (55%), cough with or without sputum production (45%), fatigue (30%), wheeze (29%), arthralgia (16%), and uveitis (16%). Ninety-two percent had pulmonary involvement, which included hilar adenopathy, symptoms, or abnormal pulmonary function testing. Eighty-five percent of the patients reported taking an average of 1.5 Sarcoid medications (range 0-5). Of patients taking medications, 78% were taking daily oral steroids, and 22% took nonsteroid therapy, such as antimalarials, inhaled bronchodilators, or methotrexate.
Access to Medical Care
Twenty percent of all patients reported being unable to see a physician when they wanted to see one (Table 4). Specifically, 10% of the patients felt they could not get medical care for Sarcoidosis when they needed it. Fifteen percent reported delaying seeking medical care because of cost. Nineteen percent had difficulty getting medication prescribed when they needed it, and 11% could not get their Sarcoid medications because they could not afford it. Patients below the poverty level were twice as likely to reportthree or more limitations to medical care than those who earned an income greater than twice the poverty level. Type of insurance was significantly associated with decreased access to care; only 4% of patients with private insurance reported three or more limitations to access as compared with 15% of Medicare patients, 23% of Medicaid patients, and 75% of those with no insurance (p < 0.01). Despite a racial difference in income, and both race and sex differences in insurance, there was no statistically significant race or sex difference in reported access to medical care.
Depression
Of the154 participants, 144 patients completed enough of the CES-D survey to calculate a score; 60% of the 144 were depressed. Women were more likely to be depressed, 66% compared with only 38% of men. Although a greater proportion of Hispanic and African-American patients were depressed, this was not statistically significant. However, if race and sex were considered together, African-American women possessed odds of being depressed that was almost four times greater than African-American men (odds ratio [OR] = 3.7l; p = 0.006); there was no statistically significant difference between white men (OR = 1.6) and women (OR = 1.8) and African-American men.
In bivariate analyses, ability to pay for medical care was significantly associated with depression; Medicare, Medicaid, and the lack of insurance all predicted high prevalence of depression (p <= 0.01). Seventy-two percent of patients below the poverty level were depressed compared with 49% of those who earned double the poverty line income (p = 0.04). Those who felt they could not see a physician in the last 12 mo when one was needed had an 89% prevalence of depression; and 100% of those who felt they could not get medical care specifically for Sarcoidosis when they needed it were depressed (Figure 1). In fact, for patients reporting any access limitation, the prevalence of depression rose by 30%. Forty-nine percent of those without limitation were depressed compared with 72% of those with one or two limitations, 89% of those with three, and 100% of those with four or five reported limitations.
As more systems were involved with Sarcoidosis, the prevalence of depression increased (Table 3); 76% of those with more than three systems involved were depressed compared with 14% of those with one system or asymptomatic disease. The only specific symptom to predict depression was dyspnea on exertion. Neither the type of treatment nor the number of medications predicteddepression in the study population.
When multivariate logistic regression was performed (Table 4), female patients were more likely to be depressed. Because two of the access questions addressed cost of care limitations, 0-2 limitations were grouped together. Those who reported three or more limitations had odds of being depressed that were 11.64 times greater than those with 0-2 limitations. The presence ofdyspnea on exertion, after adjusting for other factors, continued to predict depression. As in bivariate analysis, multivariate analysis did not reveal that steroid therapy was associated with increased depression.
| DISCUSSION |
|---|
In this study we measured the prevalence and predictors of depression in a U.S. patient population with chronic Sarcoidosis. Previous studies of patients with chronic diseases have reported associations between symptomatology and socioeconomic factors with depression (4, 12, 13). Ninety-five percent of the participants in this study reported symptoms associated with their Sarcoidosis, and 92% had pulmonary involvement (either radiologic abnormalities or respiratory symptoms); this is slightly higher than in a previous study of chronic Sarcoidosis (14). Because it has been estimated that 50 to 90% of patients with Sarcoidosisare asymptomatic (15), the high prevalence of symptomatic patients in this study likely results from the tertiary nature of the participating centers caring for more chronic Sarcoid patients; presumably,the asymptomatic patient is less likely to be diagnosed and less likely to require subspecialist care.
The most startling finding of this study is the high prevalence of depression; 60% of patients reporting symptoms of clinical depression. Increasing number of systems involved with disease and dyspnea on exertion, the most common symptom reported, predicted depression. A limitation of the CES-D, as a self-report survey, is that positive responses may result from symptoms of medical disease or from depression; our high prevalence may in part be due to symptom-loaded questions. However, the CES-D has been shown to correlate well with psychological assessment (16), and our prevalence is consistent with other chronic respiratory diseases (17, 18). Validation studies of the CES-D have shown that it can discriminate those at high risk for clinical depression; the sensitivity and specificity for depression depend on the cutoff used to separate depressed from nondepressed. The cutoff of 16 in the long-form CES-D correctly identifies 60% of those who are depressed and falsely labels 15% (11). Although our specific short-form CES-D has not been validated, multiple, other short-form CES-Ds have excellent comparability to the long-form CES-D usinga proportionate cutoff to indicate clinical depression (19).
Although pulmonary involvement did not predict depression, the presence of pulmonary disease was exceedingly high (92%), precluding any meaningful analyses of this variable. Other studies have also shown that decreased respiratory endurance correlates with decreased quality of life in Sarcoid patients (7). Although dyspnea on exertion in not an exact measure of respiratory endurance, it does suggest a decrease in respiratory reserve from which to draw during normal activities of life. Sixty-four percent of our patients were taking chronic steroids, postulated to cause dysphoria. However, previous studies on depression as a side effect of steroid use have been inconsistent, and no clear link between steroid use and depression has been found (20, 21). Our study also fails to show that steroid therapy predicts depression even after adjusting for other factors.
Drent and coworkers have studied the prevalence of depression among Sarcoid patients in the Netherlands (7). They found that the prevalence of depression was 4% in asymptomatic Sarcoidosis using the Beck Depression Inventory, and in symptomatic Sarcoidosis, the prevalence increased to 30%. Different study design and patient population may account for our study's higher prevalence of depression. In the Netherlands' study, patients with significant comorbidity were excluded, whereas in our study they were included. Also, there is evidence that our study patients had a higher prevalence of pulmonary disease as evidenced by increased reporting of respiratory symptoms (55% versus 40.5% in Drent's cohort of patients) (22). Our study population had a higher prevalence of symptoms (95% versus 58%); this increased symptomatology would predict higher prevalence of depression. Socioeconomic differences such as the lack of uniform health insurance in the United States, in contrast to the Netherlands, may also have contributed to thedifference.
Socioeconomic factors have been shown to play a large role in patient access to medical care both medications and physicians (9). Our study included only patients who were already receiving care in a tertiary care Sarcoid clinic, yet nearly 20% still reported being unable to see a physician when they felt like they needed one. We found that the patients' insurance status, income, and access to medical care were highly correlated and predicted depression. It is unclear if patient reports of reduced access to care reflectcurrent barriers limiting care or past experiences of limitations. The results of this new tool, the THA Scale, are dramatic and internally consistent, suggesting it may be a useful tool for future study. Although there was no statistical interaction between access and depression, it is conceivable that in a tertiary-care setting, these depressed patients perceive a lack of power and a consequent limitation in access to medical care. The high ratesof depression observed among our lower income patients who report access limitations may be reflective of the overall burdens and challenges in day-to-day life faced by the individuals living in poverty. Other studies have found that as income decreases, depression increases (23). Studies of asthma have consistently found that low income, racial minority status, and Medicaid or no insurance predict decreased health care utilization (26).
Although African-American patients in our study were more likely to have socioeconomic and disease severity risk factors for depression, we found that race did not predict depression in either bivariate or multivariate analyses. Other studies of race and depression have also failed to show a consistent racial differencein depression prevalence after adjusting for socioeconomic factors such as income and education (23, 24). So, although thereis a race difference in the U.S. Sarcoid population compared with Sarcoid populations in other parts of the world, race alone cannot explain our high prevalence of depression.
In our study, we found that sex predicted depression; however, many have questioned the sex bias of depression scales. Zung and coworkers found that in patients visiting primary care providers, women were more likely to be depressed than men (23% versus 16%) (27). In Los Angeles County, Frerichs and coworkers found that women were more likely to be depressed than men (24% versus 13%) at all ages (18 to greater than 70 yr of age) although the difference decreased with age (25). In one validation study, the CES-D has been found to have some sex bias resulting from certain questions (''people were unfriendly,'' ''people disliked me,'' ''life a failure,'' ''talked less,'' and ''crying spells''), which when removed, reduced the sex bias; but did not decrease the validity of the shorter survey (6). Our 11-question CES-D did not include these questions to explain the sex difference. However, in another validation study conducted by Callahan and Wolinsky three different questions (''fearful,'' ''bothered by things,'' and ''mind on what I was doing'') were found to have race and sex biases; these questions are included in our CES-D survey (28). Despite the biases found, the CES-D and short-form CES-D scales retained validity in their ability to distinguish between depressed and nondepressed populations.
The prevalence of depression in a healthy community has been estimated to be 2% for major depression and 1% for minor depression (11). Because of the high prevalence of respiratory symptoms, our patients may be best compared with patients with chronic obstructive pulmonary disease (COPD). The prevalence of depression in patients with COPD has been found to be between 29% and 50% depending upon the severity of disease (12, 17, 18). In these studies the mean age was between 62 and 65 yr which is older than our population (mean age = 47 yr). Therefore, our higher prevalence of depression may be partly related to age because other studies have found that younger age correlates with increased depression (23, 25, 29). Sarcoidosis has been compared with rheumatoid arthritis with respect to depression because of the constitutional symptoms and the need for daily medication. Previous surveys of patients with rheumatoid arthritis using the CES-D have found rates of depression between 34 and 46% (5). A side-by-side comparison conducted in the Netherlands of Sarcoid and rheumatoid arthritis patients without comorbidity showed that arthritis patients had poorer quality of life than Sarcoid patients (22); however, that study did not include any depression assessment. The researchersconcluded that quality of life was more severely affected and included more aspects of quality of life in patients with rheumatoid arthritis because of increased disease severity. This supports our results, which also show that those with more severe disease (more systems involved) are more likely to bedepressed.
The high prevalence of depression among the Sarcoid patients in this study was bly associated with female sex, lower socioeconomic status, poor access to care, and increased disease severity. The decreased respiratory reserve leading to dyspnea on exertion affects quality of life, including depression. Many of the patients who are at risk for depression are also at risk for access to medical care difficulties; whether these are causally related or colinear cannot be determined. Sarcoidosis affects a population at risk for poor quality of care, poor access to health care system, and depression. Constitutional symptoms, usually attributed to Sarcoidosis, may reflect underappreciated depression. Health care providers must be sensitive to multiple barriers facedby chronic Sarcoid patients; acknowledging and improving access to medical care and assessing for depression will promote better overall health among Sarcoid patients. Future studies of Sarcoidosis will need to address the best way to diagnose and treat depression in these patients.
| Footnotes |
|---|
Correspondence and requests for reprints should be addressed to Dr. Cynthia Rand, Ph.D., Johns Hopkins Asthma and Allergy Center, 5501 Hopkins Bayview Circle, Baltimore, MD 21224.
(Received in original form April 18, 2000 and in revised form August 23, 2000).
Acknowledgments: The authors thank Theresa Johnson, R.N., Susan Stein, M.A., Donna Winget, C.C.R.C., Marilyn Marshall, and Dawn Marie Dow without whom this study would not be possible.
Supported in part by the Eudowood Foundation (Hospital for the Consumptives of Maryland).
| References |
|---|
1. American Thoracic Society. Statement on sarcoidosis. Am J Respir Crit Care Med 1999;160:736-755.
2. Rybicki BA, Major M, Popovich J Jr,, Maliarik MJ, Iannuzzi MC. Racial differences in sarcoid incidence: a 5-year study in a health maintenance organization. Am J Epidemiol 1997; 145: 234-241
3. Johns CJ, Zachary JB, Ball WC. A ten-year study of corticosteroid treatment of pulmonary sarcoidosis. Johns Hopkins Med J 1974; 134: 271-283
4. Friis R. , Nanjundappa G. Diabetes, depression, and employment status. Soc Sci Med 1986; 23: 471-475
5. Blalock SJ, DeVellis RF, Brown GK, Wallston KA. Validity of the Center for Epidemiological Studies Depression Scale in arthritis populations. Arthritis Rheum 1989; 32: 991-997
6. Stommel M, Given BA, Given CW, Kalaian HA, Schulz R, McCorkle R. Gender bias in the measurement properties of the Center for Epidemiologic Studies Depression Scale (CES-D). Psychiatry Res 1993; 49: 239-250
7. Drent M, Wirnsberger RM, Breteler MHM, Kock LMM, de Vries J, Wouters EFM. Quality of life and depressive symptoms in patients suffering from sarcoidosis. Sarcoid Vasculitis Diffuse Lung Dis 1998; 15: 59-66 .
8. Wirnsberger RM, de Vries J, Wouters EFM, Drent M. Clinical presentation of sarcoidosis in the Netherlands: an epidemiological study. Neth J Med 1998; 15: 53-60 .
9. Okada LM, Sparer G. Access to usual source of care by race and income in ten urban areas. J Comm Health 1976; 1: 163-174 .
10. Radloff LS. The CES-D Scale: a self-report depression scale for research in the general population. Appl Psychol Meas 1977; 1: 385-401 .
11. Roberts RE, Vernon SW. The Center for Epidemiologic Studies Depression Scale: its use in a community sample. Am J Psychiatry 1983; 140: 41-46
12. Jones PW, Baveystock CM, Littlejohns P. Relationships between general health measured with the sickness impact profile and respiratory symptoms, physiological measures, and mood in patients with chronic airflow limitation. Am Rev Respir Dis 1989; 140: 1538-1543
13. Hajiro T, Nishimura K, Tsukino M, Ikeda A, Koyama H, Izumi T. Comparison of discriminative properties among disease-specific questionnaires for measuring health-related quality of life in patients with chronic obstructive pulmonary disease. Am J Respir Crit Care Med 1998; 157: 785-790
14. Johns CJ, Schonfeld SA, Scott PP, Zachary JB, MacGregor MI. Longitudinal study of chronic Sarcoidosis with low-dose maintenance corticosteroid therapy: outcome and complications. Ann NY Acad Sci 1986; 465: 702-712 .
15. Hosoda Y, Yamaguchi M, Hiraga Y. Global epidemiology of Sarcoidosis: what story do prevalence and incidence tell us? Clin Chest Med 1997; 18: 681-694
16. Knight RG, Williams S, McGee R, Olaman S. Psychometric properties of the Centre for Epidemiologic Studies Depression Scale (CES-D) in a sample of women in middle life. Behav Res Ther 1997; 35: 373-380
17. Light RW, Merrill EJ, Despars JA, Gordon GH, Mutalipassi LR. Prevalence of depression and anxiety in patients with COPD: relationship to functional capacity. Chest 1985; 87: 35-38
18. McSweeny AJ, Grant I, Heaton RK, Adams KM, Timms RM. Quality of life of patients with chronic obstructive pulmonary disease. Arch Intern Med 1982; 142: 473-478
19. Kohout FS, Berkman LF, Evans DA, Cornoni-Huntley J. Two shorter forms of the CES-D depression symptoms index. J Aging Health 1993; 5: 179-193
20. The Boston Collaborative Drug Surveillance Program. Acute adverse reaction to prednisone in relation to dosage. Clin Pharm Ther 1971;13: 694-698.
21. Patten SB, Williams JV, Love EJ. A case-control study of corticosteroid exposure as a risk factor for clinically diagnosed depressive disorders in a hospitalized population. Can J Psychiatry 1995; 40: 396-400
22. Wirnsberger RM, DeVries J, Jansen TLThA, Van Heck GL, Wouters EFM, Drent M. Impairment of quality of life: rheumatoid arthritis versus Sarcoidosis. Neth J Med 1999; 54: 86-95
23. Cockerham WC. A test of the relationship between race, socioeconomic status, and psychological distress. Soc Sci Med 1990; 31: 1321-1326
24. Fernandez ME, Mutran EJ, Reitzes DC, Sudha S. Ethnicity, gender, and depressive symptoms in older workers. Geriontologist 1998; 38: 71-79 .
25. Frerichs RR, Aneshensel CS, Clark VA. Prevalence of depression in Los Angeles County. Am J Epidemiol 1981; 113: 691-699
26. Smith LA, Finkelstein JA. Sociodemographic factors and asthma. In: Weiss KB, Buist AS, Sullivan SD, editors. Asthma's impact on society: the social and economic burden. New York: Marcel Dekker; 2000. p. 219-246.
27. Zung WWK, Broadhead WE, Roth ME. Prevalence of depressive symptoms in primary care. J Fam Prac 1993; 37: 337-344 .
28. Callahan CM, Wolinsky FD. The effect of gender and race on the measurement properties of the CES-D in older adults. Med Care 1994; 32: 341-356
29. Parkerson GR, Broadhead WE, Tse CJ. Anxiety and depressive symptoms identification using the Duke Health Profile. J Clin Epidemiol 1996; 49: 85-93
| APPENDIX |
|---|
Center for Epidemiologic Studies Depression Scale Questions
1 I was bothered by things that usually don't bother me.
2 I did not feel like eating, my appetite was poor.
3 I had trouble keeping my mind on what I was doing.
4 I felt everything I did was an effort.
5 I felt sad.
6 I felt hopeful about the future.
7 I felt fearful.
8 My sleep was restless.
9 I was happy.
10 I felt lonely.
11 I could not get going.