Psychosomatics 39:263-272, June 1998
© 1998 The Academy of Psychosomatic Medine
A Symptom Checklist to Screen for Somatoform Disorders in Primary Care
Kurt Kroenke, M.D.,
Robert L. Spitzer, M.D.,
Frank V. deGruy, III, M.D., and
Ralph Swindle, Ph.D.
Received May 7, 1997; revised November 10, 1997; accepted November 20, 1997. From the Regenstrief Institute for Health Care (KK), Richard Roudebush Veterans Affairs Medical Center (RS), Indiana University School of Medicine (KK, RS), Indianapolis; New York State Psychiatric Institute and the Department of Psychiatry, Columbia University, New York, New York (RLS); and the Department of Family Practice, University of South Alabama College of Medicine, Mobile, Alabama (Dr. deGruy). The work for this study was done at the authors' institutions. Address reprint requests to Dr. Kroenke, Regenstrief Institute for Health Care, RG–6, 1001 West 10th St., Indianapolis, IN 46202.
|
ABSTRACT
|
Current DSM-IV somatoform diagnoses may inadequately capture many somatizing patients in primary care. By using data from two studies (1,000 and 258 patients, respectively), the authors determined 1) the optimal threshold on a checklist of 15 physical symptoms to screen for a recently proposed somatoform diagnosis, multisomatoform disorder (MSD), and 2) the concordance between MSD and somatization disorder. The optimal threshold for pursuing a diagnosis of MSD was seven or more physical symptoms. The majority (88%) of the patients who met criteria for MSD had either full or abridged somatization disorder. MSD was intermediate between abridged and full somatization disorder in terms of its association with functional impairment, psychiatric comorbidity, family dysfunction, and health care utilization and charges.
Key Words: Primary Care • Somatoform Disorders • Symptom Checklist
|
INTRODUCTION
|
Somatoform disorders are present in at least 10%–15% of primary care patients.1–3 Such disorders are characterized by prominent physical complaints that cause significant functional impairment but, despite appropriate evaluation, lack a physical explanation. Both clinicians and researchers have an interest in identifying such disorders for numerous reasons. First, somatoform disorders produce impairment in patient functioning and quality of life comparable to mood and anxiety disorders.4–7 Second, somatoform disorders are associated with increased health care costs and utilization as a result of excessive clinic visits, diagnostic testing, prescriptions, subspecialty referrals, and surgical procedures.4–8 Third, patients with these disorders are much more difficult and challenging to care for than patients with most other mental disorders.7,9 Fourth, effective treatment strategies have recently been developed for aiding in the management of the somatizing patient in primary care.10–12
Many primary care clinicians characterize patients with these disorders with informal labels such as somatizers, functional illness, or multiple somatic complaints. The DSM-IV classification has several limitations for diagnosing the somatizing patient in primary care. First, most patients do not meet the high symptom threshold required for somatization disorder, yet they still demonstrate considerable functional impairment, psychiatric comorbidity, and excess health care utilization.1,4–6,13–15 Second, the clinician must inquire about not only current but also lifetime symptom experiences, a cumbersome task usually not feasible in a busy primary care setting. Undifferentiated somatoform disorder is the DSM-IV diagnosis provided for the somatizing patient whose illness does not meet criteria for somatization disorder. However, this diagnosis is a relatively recent arrival (first included in DSM-III-R), may be overly inclusive (a single unexplained symptom suffices), and lacks published evidence of its validity.
Multisomatoform disorder (MSD) has recently been proposed as an alternative to undifferentiated somatoform disorder7 and is defined as three or more currently bothersome unexplained physical complaints (from a 15-symptom checklist), plus a history of chronic somatization (i.e., unexplained symptoms, more days than not, for at least 2 years). In a study of 1,000 primary care patients,2 MSD was present in 8% of the cases and, compared with mood and anxiety disorders, was associated with comparable functional impairment, more disability days, and greater health care utilization.7
Interviewing a patient to establish the presence or absence of a somatoform diagnosis can be time-intensive, because the clinician must gather sufficient information from the patient and/or medical records to ascertain that a physical explanation for somatic complaints is unlikely. If a symptom-count threshold with suitable operating characteristics (sensitivity, specificity, predictive value) could be determined, more detailed evaluation could be reserved for the subset of patients most likely to have clinically significant somatoform disorders.
By using data from the Primary Care Evaluation of Mental Disorders (PRIME-MD) and the Somatization in Primary Care studies, we address two major questions: 1) What is the optimal threshold on a screening checklist of 15 physical symptoms for prompting a primary care clinician to pursue a diagnosis of a somatoform disorder? and 2) What is the concordance between MSD and somatization disorder? In Table 1, the key terms used in this article are defined.
|
METHODS
|
PRIME-MD 1000 Study
To determine the optimal physical symptom threshold, data were analyzed from the PRIME-MD 1000 study, a mental health survey of 1,000 patients in four primary care sites. The patients had a mean age of 55 years (range: 18–91); 60% were women, 58% were white, and 28% were college graduates. The Institutional Review Boards of each site approved the study protocol, and each patient gave signed, informed consent. Details of the PRIME-MD study, including patient sampling procedures, have been previously described.2
All subjects were evaluated with PRIME-MD, a validated diagnostic interview that consists of a 26-item self-administered Patient Questionnaire (PQ) and an accompanying Clinician Evaluation Guide (CEG).2 Criteria-based DSM-III-R diagnoses were made in five categories: mood, anxiety, somatoform, alcohol, and eating. (With minor modifications, the revised PRIME-MD yields DSM-IV diagnoses.) The subjects also completed the Somatic Symptom Inventory.16
The somatoform section of the PQ inquires about 15 physical symptoms or symptom clusters that account for over 90% of physical complaints (excluding upper respiratory symptoms such as cough, coryza, and sore throat) reported in the outpatient setting.17,18 These 15 symptoms are stomach pain; back pain; headache; chest pain; dizziness; fainting; palpitations; shortness of breath; bowel complaints (constipation or diarrhea); dyspeptic complaints (nausea, gas, or indigestion); fatigue; trouble sleeping; pain in joints or limbs; menstrual pain or problems; and pain or problems during sexual intercourse. The symptoms are prefaced in the PQ by the query: "During the past month, have you been bothered a lot by 1) stomach pain? 2) back pain?...."
In the original study, the clinicians filled in the CEG somatoform module for any patient who endorsed three or more physical symptoms on the PQ. In the CEG, the clinician is asked to decide: "Based on your clinical judgment, does the symptom have a physical explanation that is adequate to explain its severity and associated disability?" Only if the clinician answered "No" was the symptom classified as somatoform. An important exception is that if the patient meets criteria for a mood or anxiety disorder, symptoms explicitly part of the diagnostic criteria for that disorder (e.g., fatigue or insomnia for a mood disorder, cardiopulmonary or gastrointestinal symptoms for panic disorder) are not counted as somatoform. In short, PRIME-MD requires that a physical symptom be recently bothersome and physically unexplained before it is classified as somatoform. A patient with three or more somatoform symptoms plus at least a 2-year history of chronic somatization is diagnosed with MSD, whereas those who have three or more somatoform symptoms but do not meet the chronicity criterion are diagnosed with somatoform disorder, not otherwise specified (NOS).
Somatization in Primary Care Study
To determine the concordance between MSD and somatization disorder, data were analyzed from the Somatization in Primary Care Study, a representative sample of 286 patients drawn equally from the waiting rooms of three family practices in or near Mobile, Alabama. Because of the small number of men (n=28), we focus on the 258 women, whose mean age was 47 years; 81% were Caucasian, 17% African American, and 2% other.
An 11-item screener19 was used to select a representative sample of adults weighted for somatizing patients. All patients were evaluated with the Diagnostic Interview Schedule (DIS),20 which in its somatization module inquires about the full list of 35 possible symptoms required to establish a diagnosis of somatization disorder. This sample included 85 women with somatization disorder by DSM-III-R criteria, 84 women with 6 to 12 unexplained symptoms, referred to as abridged somatization disorder,13 and 89 women with fewer than 6 unexplained symptoms. The DIS raw data file was recoded to conform to the PRIME-MD diagnosis of MSD, and patients with MSD were compared with patients meeting DSM-III-R criteria for full, abridged, or no somatization disorder.
Functional status and quality of life was assessed with the Medical Outcome Study 36-Item Short-Form Health Survey.21 A family genogram was obtained by a structured interview and included family-of-origin data on childhood conflict, alcohol abuse, criminal behavior, physical violence, and abuse. Health care visits and charges were determined by review of medical records and billing.
Statistical Analysis
Chi-square analysis and analysis of variance were used for univariate comparisons of categorical and continuous variables, respectively. The sensitivity, specificity, and predictive values of various symptom thresholds for MSD were calculated.22 The likelihood ratio associated with each specific symptom count was also calculated.23 The concordance between PRIME-MD somatoform symptom counts and DSM-III-R abridged and full somatization disorder was determined. Multivariate logistic regression analysis was performed to examine whether all physical symptoms or only certain symptoms were independently associated with MSD. To determine whether symptoms grouped into certain domains and whether these domains were differentially associated with MSD, factor analysis was conducted with the maximum likelihood method, using both varimax and oblique rotations.
|
RESULTS
|
What Symptom Threshold Should Prompt Further Evaluation for Somatoform Disorders?
MSD was diagnosed in 82 (8.2%) of the 1,000 patients in the PRIME-MD 1000 study and somatoform disorder NOS in 42 (4.2%). There was a strong correlation (r=0.74) between the PRIME-MD physical symptom count and the Somatic Symptom Inventory score.
Table 2 shows the performance characteristics of various physical symptom thresholds for predicting MSD. As with any diagnostic test, sensitivity declines and specificity increases as the threshold for a "positive" test (in this case, symptom count) is progressively increased. The decline in sensitivity is relatively small with each additional physical symptom until the threshold is raised from seven symptoms to eight, at which point sensitivity drops more dramatically, from 85% to 68%. The positive and negative predictive values for a physical symptom threshold of seven indicate that 25% of patients who endorse seven or more physical symptoms on the PRIME-MD questionnaire will have MSD, whereas only 2% of patients who endorse 6 or fewer symptoms will have MSD.
We also assessed the optimal physical symptom threshold for predicting whether a patient had three or more somatoform symptoms, irrespective of chronicity (i.e., either MSD or somatoform disorder NOS). For diagnosing this group of 129 patients who had either MSD (n=82) or somatoform disorder NOS (n=47), a physical symptom threshold of seven again appeared an optimal compromise between sensitivity (76%) and specificity (79%). The positive and negative predictive values at this threshold were 35% and 96%, respectively.
Table 3 shows the likelihood ratios associated with specific physical symptom counts, calculated as the ratio of the probability of a given symptom count in patients with and without MSD. For example, there were 80 patients who endorsed seven physical symptoms on the PRIME-MD, and the likelihood ratio associated with a symptom count of seven was (14/82)÷(66/918)=2.37. This means that a physical symptom count of seven is 2.37 times more likely to occur in the patients with MSD than in the patients without MSD (compared with a likelihood ratio of only 0.93 for a physical symptom count of six). Results were similar when applied to the 129 patients who had either MSD or somatoform disorder NOS, where likelihood ratios for six and seven physical symptoms were 0.92 and 2.56, respectively. Likelihood ratios are a way of combining sensitivity and specificity information into a single number, and these findings provide additional evidence for using a physical symptom count of seven or greater as a trigger for more detailed probing to diagnose somatoform disorders in primary care.
Individual Symptoms and MSD
The association between individual symptoms (both any physical symptom as well as the subset that were somatoform) and MSD was examined with both univariate and multivariate analyses. Each of the 15 symptoms had a significant univariate association with MSD: the unadjusted odds ratios were typically in the range of 3 to 8 for most physical symptoms, and 10 to 30 for somatoform symptoms. To assess the strength of each symptom as an independent predictor of MSD, adjusted odds ratios were calculated by using multivariate logistic regression analysis, controlling for the presence of each of the other 14 symptoms. As shown in Table 4, fewer symptoms remained as independent predictors, but these symptoms were from all three domains identified by factor analysis (described next) rather than clustering in a single domain. Of note, the rank ordering of somatoform symptoms as predictors differs somewhat from physical symptoms in general. For example, the patients with abdominal pain were only 1.6 times more likely to have MSD than the patients without abdominal pain, but the former were 12 times more likely to have MSD if their abdominal pain was unexplained. On the other hand, diarrhea/constipation was an insignificant predictor, whether all patients with this symptom or only those whose symptom was somatoform were analyzed. Fatigue went from being the strongest predictor when all patients with fatigue were included to being the weakest predictor when only those with unexplained fatigue were included. This finding may in part be due to the fact that as one of the diagnostic criteria for mood disorders, fatigue is not counted as somatoform by the PRIME-MD algorithm if criteria for a mood disorder are met.
On factor analysis, two symptoms (menstrual pain and painful sex) were removed because of low communalities with the other items, and the remaining 13 items were refactored. An interpretable simple structure emerged from the oblique solution suggesting three intercorrelated factors: cardiopulmonary (chest pain, palpitations, fainting, shortness of breath, and dizziness); gastrointestinal (stomach pain, diarrhea/constipation, nausea/gas); and general pain/fatigue (back pain, joint/limb pain, headaches, fatigue, and sleep problems). Cronbach's alpha for these three scales ranged from 0.59 to 0.67, reasonable internal consistency for scales with only a small number of items. These three factors accounted for 46% of the total variance.
Discriminant analysis revealed that each factor was strongly and independently correlated with the discriminant function for MSD; the correlation coefficients for the cardiopulmonary, gastrointestinal, and fatigue/pain factors were 0.84, 0.82, and 0.65, respectively. Results were similar when the dependent variable was somatoform disorder, NOS. Logistic regression analysis confirmed that each of the three factors independently predicted a somatoform diagnosis. Both symptom-level and factor-level analyses indicates that the best combination of screening items for these somatoform diagnoses are symptoms from multiple domains rather than a single somatic dimension.
Concordance of PRIME-MD MSD and DIS Somatoform Diagnoses
Of the 286 patients in the Somatization in Primary Care Study, 146 qualified for a diagnosis of MSD. Most MSD patients met criteria for either full (53%) or abridged (35%) somatization disorder; only 12% did not meet criteria for one of these somatoform diagnoses. Looked at another way, MSD had a sensitivity of 72% (129 of the 180 patients with either full or abridged somatization disorder had MSD) and a specificity of 84% (89 of the 106 patients with neither full nor abridged disorder did not have MSD).
Table 5 provides data on the 258 women patients according to level of somatization. MSD is intermediate between abridged and full somatization disorder in terms of multiple, clinically relevant variables, including functional impairment, psychiatric comorbidity, family dysfunction, and health care utilization and charges.
|
DISCUSSION
|
Two important findings emerge from our analysis of the PRIME-MD 1000 and Somatization in Primary Care data sets. First, the physical symptom count for triggering further evaluation for somatoform disorders when using the 15-symptom checklist can be raised from the original threshold of three to a higher one of seven. In the PRIME-MD 1000 study, this would have reduced the proportion of patients requiring further probing to establish or exclude a somatoform diagnosis from 67% to 28%, a critical consideration given the busy nature of primary care practice. Second, MSD is a moderately severe somatizing disorder associated with substantial impairment in all eight domains of health-related quality of life, considerable psychiatric comorbidity, high rates of family dysfunction, and excess health care utilization.
While several screening indices have been previously proposed for somatization disorder, these indices were not derived from primary care samples. A seven-symptom index proposed by Othmer and DeSouza24 was studied in a small sample of psychiatric outpatients with multiple unexplained physical complaints, while an 11-item index developed by Swartz and colleagues19 was derived from the Epidemiologic Catchment Area study, a large mental health survey conducted in the general population. Primary care patients with physical complaints may differ substantially from both patients referred to mental health specialists as well as individuals interviewed in the community (i.e., "nonpatients"). Indeed, subsequent evaluation of these indices in a primary care sample did show some decrement in their performance.25
Of note, the PRIME-MD 15-symptom checklist includes 5 of the 7 symptoms in the Othmer-Desouza index (all except amnesia and lump in the throat) and 9 of the 11 symptoms in the Swartz index (all except weakness and feeling sickly). This may explain in part the high concordance between PRIME-MD and DIS somatoform diagnoses.
Increasingly, studies have shown that restricting one's attention to diagnosing the relatively uncommon somatization disorder fails to capture an important group of somatizing patients in primary care who experience global functional impairment, psychiatric comorbidity, difficult doctor–patient relationships, and excess health care utilization.1,4–9,13–15 Strategies that are useful for managing somatization disorder26 also appear effective in patients with abridged somatization disorder.10 Since most patients with MSD have either abridged or full somatization disorder, they probably should be managed in a similar fashion pending further clinical trials.
Abridged somatization disorder as defined by Escobar and studied by others is a lifetime history of 4 medically unexplained symptoms for men or 6 for women out of the list of 35 potential symptoms proposed for somatization disorder in DSM-III-R.4,13,15 Escobar labeled this the Somatic Symptom Index, or SSI–4/6.13 Recently, the number of symptoms required to diagnose somatization disorder has been reduced from 13 of 35 (DSM-III-R) to 8 of 33 (DSM-IV). Rief and colleagues27 have preliminary data from 108 psychiatric inpatients showing that 3 unexplained symptoms for men or 5 for women out of the list of 33 DSM-IV somatization symptoms (SSI–3/5) is equivalent to Escobar's SSI–4/6. Both the SSI–4/6 and SSI–3/5 require clinicians to inquire about twice as many symptoms as our 15-symptom checklist and to take not only a current but also a lifetime symptom history. Diagnostic efficiency is a major issue in primary care where the average visit is only 13 minutes.17
Why did the patients with MSD (three or more current unexplained symptoms) have similar or more impairment, psychiatric comorbidity, family dysfunction, and excess health care utilization than the patients with abridged somatization disorder (6–12 lifetime unexplained symptoms)? Three reasons for this somewhat counterintuitive finding can be gleaned from Table 1. First, MSD is based upon current rather than lifetime somatoform symptom counts. Second, MSD relies upon a 15-symptom rather than 35-symptom checklist. It is likely that the majority of patients meeting criteria for MSD would have higher somatoform symptom counts if past symptoms not currently bothersome were allowed and if a symptom checklist more than twice as long were used. Indeed, this finding was verified in our sample, in which 88% of the patients meeting criteria for MSD on the recoded DIS had either full or abridged somatization disorder. Third, since MSD is diagnosed by a symptom threshold rather than range, it includes most patients with full as well as abridged somatization disorder, whereas the latter, by definition, excludes patients with full somatization disorder. Although MSD combines in a single category patients with varying degrees of somatization, somatoform symptom counts can be used as one measure of MSD severity since previous work has shown that functional impairment is directly correlated with the number of unexplained symptoms.7
Analysis at both the individual symptom level as well as the three-factor level suggests it is not the type of symptom but rather the total symptom count that most strongly predicts a somatoform diagnosis. Cloninger has reviewed the historical shifts regarding symptom grouping and somatization disorder.28 The original criteria for Briquet syndrome, from which DSM-III criteria for somatization disorder were derived, required at least 1 symptom in at least 9 of 10 possible groups. DSM-III dropped requirements about the number of groups, because the total number of somatization symptoms was highly correlated with the number of somatization groups. DSM-IV has resurrected a requirement for number of groups: at least four pain symptoms, two gastrointestinal symptoms, one conversion symptom, and one sexual symptom. The abbreviated criteria for somatization disorder in the International Classification of Disease, 10th Edition, require symptoms to be distributed over at least two of four groups (cardiopulmonary, gastrointestinal, genitourinary, and skin and pain symptoms), although the conversion symptom category required in DSM-IV is excluded altogether. While all agree that symptom counts are important, requiring symptoms from a certain number of groups (and if so, which specific groups) is still open to debate.
Several limitations of our analysis should be mentioned. First, patients in one of our two samples (Somatization in Primary Care Study) were interviewed with the DIS rather than actual completion of the PRIME-MD symptom checklist. Although we suspect most patients that we classified as having MSD by recoding DIS responses would have been similarly diagnosed had they completed the PRIME-MD 1000, this should be verified in future studies. Second, symptoms in the PRIME-MD 1000 sample were classified as somatoform by the primary care physician; independent assessment of symptoms by a second rater with calculation of interobserver agreement would have further strengthened our findings. It is also important to compare, in both primary care as well as psychiatric patient samples, the diagnostic efficiency and concordance of the three abridged somatization disorder constructs: SSI–4/6, SSI–3/5, and MSD.
Third, we assessed concordance of MSD with full and abridged somatization disorder, as determined by DSM-III-R rather than DSM-IV criteria, partly because the original patient samples were assembled by using DSM-III-R criteria and also because most of the prior research on abridged somatization disorder has been based on DSM-III-R criteria. Had DSM-IV criteria been used, however, it would have been unlikely to alter our findings, since recent field trials have shown that most patients who meet DSM-III-R criteria for somatization disorder will meet DSM-IV criteria as well.29
Fourth, the specificity of a seven-symptom cut-off might decline in medical populations in which there are a large number of patients with illnesses like AIDS (acquired immunodeficiency syndrome), tuberculosis, metastatic cancer, systemic lupus erythematosus, and other multisystem diseases. However, such patients constitute only a small proportion of primary care clinic populations and usually have obvious clues on history or physical examination that their diagnosis is not somatoform. Indeed, recent studies have shown that the primary care physician's gestalt about a symptom being medically unexplained is quite good and that few patients with symptoms initially judged to be somatoform were later found to have occult, serious physical disorders at follow-up.30,31
MSD is a moderately severe somatoform diagnosis intermediate in severity between full and abridged somatization disorder and should be considered when a patient reports 7 or more of the 15 physical symptoms that comprise a simple screening checklist. This symptom threshold identifies a subgroup of primary care patients at higher risk of having clinically significant somatization. Clinicians and researchers could use the symptom checklist either by itself or as part of the PRIME-MD diagnostic instrument. Identification of somatoform disorders in primary care is warranted because of their prevalence, impaired functioning and quality of life, excess costs and utilization, and patient difficulty, as well as emerging evidence for management strategies that have at least some degree of efficacy.
|
ACKNOWLEDGMENTS
|
The development of the PRIME-MD was underwritten by an unrestricted educational grant from the Roerig and Pratt Pharmaceuticals division of Pfizer Inc., New York. The Somatization in Primary Care Study was supported by a grant from the National Institute of Mental Health (Grant No. MH45441), Bethesda, MD.
The authors thank the following persons for their help in project design and data collection: Janet Williams, Steven Hahn, Mark Linzer, David Brody, and Linda Dickinson.
|
REFERENCES
|
-
Kirmayer LJ, Robbins JM: Three forms of somatization in primary care: prevalence, co-occurrence, and sociodemographic characteristics. J Nerv Ment Dis 1991; 179:647–655[Medline]
-
Spitzer RL, Williams JBW, Kroenke K, et al: Utility of a new procedure for diagnosing mental disorders in primary care: the PRIME-MD 1000 study. JAMA 1994; 272:1749–1756[Abstract]
-
Kellner R: Functional somatic symptoms and hypochondriasis: a survey of empirical studies. Arch Gen Psychiatry 1985; 42:821–833 [Abstract]
-
Katon W, Lin E, Von Korff M, et al: Somatization: a spectrum of severity. Am J Psychiatry 1991; 148:34–40 [Abstract/Free Full Text]
-
Smith GR, Monson RA, Ray DC: Patients with multiple unexplained symptoms: their characteristics, functional health, and health care utilization. Arch Intern Med 1986; 146:69–72 [Abstract]
-
Swartz M, Landerman R, George LK, et al: Somatization disorder, in Psychiatric Disorders in America, edited by Robins LN, Regier DA. New York, Free Press, 1991, pp. 220–257
-
Kroenke K, Spitzer RL, deGruy FV, et al: Multisomatoform disorder: an alternative to undifferentiated somatoform disorder for the somatizing patient in primary care. Arch Gen Psychiatry 1997; 54:352–358[Abstract]
-
Smith GR: The course of somatization and its effects on utilization of health care resources. Psychosomatics 1994; 35:263–267[Abstract/Free Full Text]
-
Hahn SR, Thompson KS, Wills TA, et al: The difficult doctor–patient relationship: somatization, personality and psychopathology. J Clin Epidemiol 1994; 47:647–657 [Medline]
-
Smith GR, Rost K, Kashner TM: A trial of the effect of a standardized psychiatric consultation on health outcomes and costs in somatizing patients. Arch Gen Psychiatry 1995; 52:238–243 [Abstract]
-
Speckens AEM, van Hemert AM, Spinhoven P, et al: Cognitive behavioural therapy for medically unexplained physical symptoms: a randomized controlled trial. BMJ 1995; 311:1328–1332[Abstract/Free Full Text]
-
Goldberg RJ, Novack DH, Gask L: The recognition and management of somatization: what is needed in primary care training. Psychosomatics 1992; 33:55–61[Abstract/Free Full Text]
-
Escobar JI, Rubio-Stipec M, Canino G, et al: Somatic Symptom Index (SSI): a new and abridged somatization construct. Prevalence and epidemiological correlates in two large community samples. J Nerv Ment Dis 1989; 177:140–146 [Medline]
-
Deighton CM, Nicol AR: Abnormal illness behaviour in young women in a primary care setting: is Briquet's Syndrome a useful category? Psychol Med 1985; 15:515–520
-
Hiller W, Rief W, Fichter MM: Further evidence for a broader concept of somatization disorder using the Somatic Symptom Index. Psychosomatics 1995; 36:285–294 [Abstract/Free Full Text]
-
Wyshak G, Barsky AJ, Klerman GL: Comparison of psychiatric screening tests in a general medical setting using ROC analysis. Med Care 1991; 29:775–785 [Medline]
-
Schappert SM: National Ambulatory Medical Care Survey: 1991 summary. National Center for Health Statistics. Vital Health Stat 1993; 230:1–15
-
Kroenke K, Arrington ME, Mangelsdorff AD: The prevalence of symptoms in medical outpatients and the adequacy of therapy. Arch Intern Med 1990; 150:1685–1689[Abstract]
-
Swartz M, Hughes D, George L, et al: Developing a screening index for community studies of somatization disorder. J Psychiatr Res 1986; 20:335–343 [Medline]
-
Robins LN, Helzer JE, Croughan J, et al: National Institute of Mental Health Diagnostic Interview Schedule: its history, characteristics, and validity. Arch Gen Psychiatry 1981; 38:381–389[Abstract]
-
Ware JE, Sherbourne CD: The MOS 36-Item Short-Form Health Survey (SF-36): I. Conceptual framework and item selection. Med Care 1992; 30:473–483[Medline]
-
Sackett DL, Haynes RB, Tugwell P: Clinical Epidemiology: A Basic Science for Clinical Medicine. Boston, MA, Little, Brown, 1985
-
Radack KL, Rouan G, Hedges J: The likelihood ratio: an improved measure for reporting and evaluating diagnostic test results. Arch Pathol Lab Med 1986; 110:689–693[Medline]
-
Othmer E, DeSouza C: A screening test for somatization disorder (hysteria). Am J Psychiatry 1985; 142:1146–1149 [Abstract/Free Full Text]
-
Smith GR, Brown FW: Screening indexes in DSM-III-R somatization disorder. Gen Hosp Psychiatry 1990; 12:148–152[Medline]
-
Smith GR, Monson RA, Ray DC: Psychiatric consultation in somatization disorder: a randomized, controlled study. N Engl J Med 1986; 314:1407–1413 [Abstract]
-
Rief W, Heuser J, Mayrhuber E, et al: The classification of multiple somatoform symptoms. J Nerv Ment Dis 1996; 184:680–686[Medline]
-
Cloninger CR: Somatization disorder, in DSM-IV Sourcebook, Vol. 2, edited by Widiger TA, Frances AJ, Pincus AH, et al. Washington, DC, American Psychiatric Association, 1996, pp. 885–892
-
Yutzy SH, Cloninger CR, Guze SB, et al: DSM-IV field trial: testing a new proposal for somatization disorder. Am J Psychiatry 1995; 152:97–101[Abstract/Free Full Text]
-
Martina B, Bucheli B, Stotz M, et al: First clinical judgment by primary care physicians distinguished well between nonorganic and organic causes of abdominal or chest pain. J Gen Intern Med 1997; 12:459–465[Medline]
-
Kroenke K: Symptoms and science: the frontiers of primary care research. J Gen Intern Med 1997; 12:509–510[Medline]
This article has been cited by other articles:
|
|
|
|
 
J. L. Jackson and K. Kroenke
Prevalence, Impact, and Prognosis of Multisomatoform Disorder in Primary Care: A 5-Year Follow-up Study
Psychosom Med,
May 1, 2008;
70(4):
430 - 434.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. A. A. Kanaan, J. P. Lepine, and S. C. Wessely
The Association or Otherwise of the Functional Somatic Syndromes
Psychosom Med,
November 1, 2007;
69(9):
855 - 859.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. Hasin and H. Katz
Somatoform and Substance Use Disorders
Psychosom Med,
November 1, 2007;
69(9):
870 - 875.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
K. Kroenke, M. Sharpe, and R. Sykes
Revising the Classification of Somatoform Disorders: Key Questions and Preliminary Recommendations
Psychosomatics,
August 1, 2007;
48(4):
277 - 285.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
B. A. Arnow, E. M. Hunkeler, C. M. Blasey, J. Lee, M. J. Constantino, B. Fireman, H. C. Kraemer, R. Dea, R. Robinson, and C. Hayward
Comorbid depression, chronic pain, and disability in primary care.
Psychosom Med,
March 1, 2006;
68(2):
262 - 268.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
R E Clouse and P J Lustman
USE OF PSYCHOPHARMACOLOGICAL AGENTS FOR FUNCTIONAL GASTROINTESTINAL DISORDERS
Gut,
September 1, 2005;
54(9):
1332 - 1341.
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. J. Barsky, E. J. Orav, and D. W. Bates
Somatization Increases Medical Utilization and Costs Independent of Psychiatric and Medical Comorbidity
Arch Gen Psychiatry,
August 1, 2005;
62(8):
903 - 910.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. C. Smith, J. C. Gardiner, J. S. Lyles, C. Sirbu, F. C. Dwamena, A. Hodges, C. Collins, C. Lein, C. W. Given, B. Given, et al.
Exploration of DSM-IV Criteria in Primary Care Patients With Medically Unexplained Symptoms
Psychosom Med,
January 1, 2005;
67(1):
123 - 129.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. J. Barsky and D. K. Ahern
Cognitive Behavior Therapy for Hypochondriasis: A Randomized Controlled Trial
JAMA,
March 24, 2004;
291(12):
1464 - 1470.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
H. J. Grabe, C. Meyer, U. Hapke, H.-J. Rumpf, H. J. Freyberger, H. Dilling, and U. John
Specific Somatoform Disorder in the General Population
Psychosomatics,
August 1, 2003;
44(4):
304 - 311.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. D. Richardson, C. C. Engel Jr., S. C. Hunt, K. McKnight, and M. McFall
Are Veterans Seeking Veterans Affairs' Primary Care as Healthy as Those Seeking Department of Defense Primary Care? A Look at Gulf War Veterans' Symptoms and Functional Status
Psychosom Med,
July 1, 2002;
64(4):
676 - 683.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
K. Kroenke, R. L. Spitzer, and J. B. W. Williams
The PHQ-15: Validity of a New Measure for Evaluating the Severity of Somatic Symptoms
Psychosom Med,
March 1, 2002;
64(2):
258 - 266.
[Abstract]
[Full Text]
|
|
|
|
|
|
|
A. Feder, M. Olfson, M. Gameroff, M. Fuentes, S. Shea, R. A. Lantigua, and M. M. Weissman
Medically Unexplained Symptoms in an Urban General Medicine Practice
Psychosomatics,
June 1, 2001;
42(3):
261 - 268.
[Abstract]
[Full Text]
|
|
|
|
|
|
|
K. Kroenke
Studying Symptoms: Sampling and Measurement Issues
Ann Intern Med,
May 1, 2001;
134(9_Part_2):
844 - 853.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
G. C. Smith, D. M. Clarke, D. Handrinos, A. Dunsis, and D. P. McKenzie
Consultation-Liaison Psychiatrists' Management of Somatoform Disorders
Psychosomatics,
December 1, 2000;
41(6):
481 - 489.
[Abstract]
[Full Text]
|
|
|
|
|
|
|
R. Noyes Jr., D. R. Langbehn, R. L. Happel, L. R. Sieren, and B. A. Muller
Health Attitude Survey: A Scale for Assessing Somatizing Patients
Psychosomatics,
December 1, 1999;
40(6):
470 - 478.
[Abstract]
[Full Text]
|
|
|
|
|
|
|
P. G. O'Malley, J. L. Jackson, K. Kroenke, I. K. Yoon, E. Hornstein, and G. J. Dennis
The Value of Screening for Psychiatric Disorders in Rheumatology Referrals
Arch Intern Med,
November 23, 1998;
158(21):
2357 - 2362.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
G. A. Fava, P. Porcelli, and K. Kroenke
Multisomatoform Disorder
Arch Gen Psychiatry,
August 1, 1998;
55(8):
756 - 757.
[Full Text]
[PDF]
|
|
|
|
TOP
ABSTRACT
INTRODUCTION