The contribution of epidemiology to psychosomatic medicine

OBJECTIVE

To discuss the contribution of epidemiology and epidemiological methods to psychosomatic medicine.

METHOD

Critical review of the literature, including both philosophical concepts and empirical data.

RESULTS

The adjective "psychosomatic" has been used in two different ways: in the so called "psychosomatic" or holistic approach to medicine; and in a narrower approach, referring to particular disorders in which psychological factors were considered to have a fundamental aetiological role. While the ideal of the holistic, "humanistic" or "anthropological" approach should probably be never abandoned, the practical limitations of encompassing models, including Engel's bio-psycho-social model are also obvious: they may be heuristically sterile. On the other side, in relation to the narrow psychosomatic approach, psychogenetic views in the so called "psychosomatic illnesses" have been strongly criticized on empirical grounds. The potential of epidemiological methods to study these illnesses, but also "somatopsychic" disorders is shown in a number of papers in the empirical literature. We have grouped such contributions, including our own experience, in the five categories suggested by M. Shephered for epidemiological methods in general: 1) the completion of the spectrum of disease; 2) the establishment of outcome; 3) the actuarial assessment of morbid risk; 4) the evaluation of the efficacy of treatment; and 5) the conceptual construction of diagnosis and classification.

CONCLUSIONS

The contribution of epidemiological data to areas of interest in psychosomatic medicine has been relevant in recent years. The potential of epidemiological methods in this area is very important both to increase knowledge and to improve the quality of clinical practice.

Screening of somatization disorder: validation of the Spanish version of the Othmer and DeSouza test

The objective of this study was to validate the Spanish version of the Othmer and DeSouza Screening Test for Somatization Disorder. We have designed a validity study using the Standardized Polyvalent Psychiatric Interview, an instrument specifically designed to diagnose psychiatric morbidity in medical settings as the 'golden rule'. The control group displayed 'functional' and 'presenting' somatization. The Othmer and DeSouza Screening Test, with a threshold of three symptoms, shows 88% sensitivity, 78% specificity and a misclassification rate of 17%. It is concluded that Othmer and DeSouza's screening test, with a threshold of three symptoms, is a useful tool for the diagnosis of somatization disorder in medical and primary care settings in Spain. Discrepancies with US findings are discussed on a cross-cultural basis.

Somatisation in primary care in Spain: I. Estimates of prevalence and clinical characteristics. Working Group for the Study of the Psychiatric and Psychosomatic Morbidity in Zaragoza

BACKGROUND

This is the first attempt to study the prevalence and clinical characteristics of somatisation (ST) in a representative primary care sample in Spain.

METHOD

The sample consisted of 1559 consecutive patients attending eight randomly selected health centres in Zaragoza, Spain, examined by two-phase screening. First phase (lay interviewers): Spanish versions of GHQ-28, CAGE questionnaire, substance abuse, Mini-Mental State Examination. Second phase (research clinicians and psychiatrists): Standardised Polyvalent Psychiatric Interview, which permits the reliable coding of Bridges & Goldberg's ST criteria.

RESULTS

The prevalence of somatisers was 9.4% (34.5% of the cases) and most patients (68.7%) were diagnosed in the depression or anxiety DSM-IV categories. The severity was moderate in 401% and 66.6% were chronic (six or more months). No significant demographic differences were found with non-cases. Backache was the most frequent somatic presentation (71.4+%).

CONCLUSIONS

ST in primary care is a much broader phenomenon than categories such as somatoform disorders reflect. It may be less influenced by sociodemographic factors, but more chronic than previously reported.

Somatisation in primary care in Spain: II. Differences between somatisers and psychologisers. Working Group for the Study of the Psychiatric and Psychosomatic Morbidity in Zaragoza

BACKGROUND

This study is the first attempt to document the differences between somatisers (STs) and psychologisers (PGs) in Spanish primary care patients.

METHOD

A sample of 1559 consecutive patients attending eight randomly selected health centres in Zaragoza, were examined in a two-phase screening using Spanish versions of GH-28, CAGE questionnaire, substance abuse, MMSE and SPPI. STs and PGs were diagnosed according to operationalised Bridges & Goldberg's criteria.

RESULTS

ST was found to be three times more prevalent than PG, but the ratio ST: PG was highest (10.5) in the DSM-IV category dysthymia. Generalised anxiety disorder was the most frequent diagnosis in STs and major depressive episode the most frequent in PGs. No significant differences between the two groups have been found in demographic characteristics. Total GHQ scores were significantly higher in PGs, but global SPPI scores were not. Most psychopathological scores were higher in PGs, but both somatic symptoms and suspiciousness were higher in STs. The psychopathological findings are consistent with hypotheses related to blame avoidance and defensiveness in STs.

CONCLUSIONS

ST is three times more prevalent than PG, but the ratio ST: PG depends heavily on diagnostic categories. While most psychopathological scores are higher in PGs, both patient groups are similarly disturbed. Previously assumed socio-demographic differences between STs and PGs have not been found in this study.

Anxiety, depression and management of medically unexplained symptoms in medical clinics

This study assessed the prevalence of medically unexplained symptoms in cardiology, gastroenterology and neurology outpatient clinics at a large teaching hospital and investigated the current clinical management of these patients. Data were collected retrospectively from the casenotes of all new referrals to these clinics over a two month period. The total number of new patients seen was 343, of whom 120 (35%) had a final diagnosis of 'functional' disorder, 204 (59.5%) a final diagnosis of organic disorder and 19 (5.5%) remained undiagnosed. The number of investigations was similar in patients whether the eventual diagnosis was 'functional' or organic (median 2, range 0-9 in each case). However, the cost of investigation was significantly higher for the organic group (median 89 pounds compared with 41 pounds, p > or = 0.01). Anxiety and depression were documented in 33% of patients with unexplained symptoms. In 73 (61%) of patients with an eventual 'functional' diagnosis, the information that organic disease had been excluded was communicated to the GP, but there was no advice about further management. Four percent were referred to psychiatrists and 2% started on antidepressants. The paucity of recommended management strategies for patients with a 'functional' diagnosis suggests that physicians see their role with this group of patients as primarily one of exclusion of organic disease. It is suggested that more positive management strategies, including treatment of anxiety and depression, might lead to greater patient satisfaction and play a role in reducing the development of chronic somatisation.

[Somatization disorders in primary care: differential clinical aspects. Study Group of Psychic and Psychosomatic Morbidity of Zaragoza, Primary Care Section]

BACKGROUND

To identify specific sociodemographic and psychopathological features of somatization disorder (SD) patients in relation to other patients with psychiatric and organic morbidity in primary care (PC) setting.

METHODS

A group of SD patients from PC was compared with other two control groups: the first one made of patients with psychiatric morbidity (with or without organic disease) and the second group of patients with only organic disease without psychiatric morbidity. Polivalent standardized psychiatric interview (PSPI), a specific psychiatric interview for PC settings, was used as diagnostic instrument.

RESULTS

1) there is a female predominance in SD statistically significant compared with organic patients and with a trend to significance in relation to psychiatric patients. Age, marital status and educational level show no significant differences among the groups; 2) in relation to psychopathology, SD patients show, in relation with organic patients, statistically higher levels in all items measured by PSPI. On the contrary, SD overwhelmed psychiatric patients in just four items: somatic symptoms, fatigue, reported anxiety and hystrionism as well as sexual problems and lack of social support, and 3) high psychiatric morbidity (85%) in SD, most of them affective and anxiety diagnosis, make it difficult to differentiate from the other patients suffering from psychiatric morbidity in PC.

CONCLUSION

Patients with SD show a very different profile compared with those with organic disease in relation to psychiatric symptoms and social problems. On the other hand, when compared with patients with psychiatric disorders, differences are rather scarce. In addition, affective and anxiety comorbidity associated make it difficult the diagnosis. For this reason, the use of screening instruments for SD seems mandatory.

HIV-related knowledge and risk behaviors of street youth in Belo Horizonte, Brazil. The Street Youth Study Group

Individual interviews were conducted with 379 youth who work and/or live on the streets of a large Brazilian city to assess HIV-related knowledge, sources of information, risk behaviors, and prevention beliefs and strategies. Respondents demonstrated high levels of factual knowledge about HIV transmission (84% correct) coupled with high levels of misconceptions about casual transmission (53% correct) and intermediate levels of knowledge about prevention (64% correct). Only 54% of the respondents had heard about AIDS recently, and 37.5% said they talked to someone about AIDS. The most common sources of information about HIV/AIDS were the mass-media and friends. Over half the sample reported taking precautions to reduce their risk of HIV infection; however, the proportion of youth taking effective precautions was low. Among the 247 youth (65% of the sample) who had initiated sexual activity, lifetime condom use was reported by 18%, and condom use at last intercourse by 10%. Youth with higher levels of knowledge were more likely to report behavior changes to avoid HIV infection. These findings underscore the urgent need for prevention programs tailored to street youth in developing countries.

Response of foot-and-mouth disease virus C3 Resende to immunological pressure exerted in vitro by antiviral polyclonal sera

The foot-and-mouth disease virus (FMDV) shows a remarkable antigenic variability. Like other RNA viruses, FMDV has a high mutation rate and it has been proposed that selection exerted by antibodies of the host could play a major role in its evolution. In this work, antiserum-resistant variants of FMDV (Nr variants) were selected upon 25 serial passages of a cloned C3 Resende strain on secondary monolayers of fetal bovine kidney (FBK-2) cells in the presence of subneutralizing levels of antiviral polyclonal sera (APS). After serial passage under immune selective pressure, the five Nr variant populations selected from five independent serial passages--their controls remaining unmodified--acquired the following characteristics: (i) increased resistance to neutralization by APS; (ii) five different antigenic specificities detected by enzyme-linked and neutralization assays using monoclonal antibodies; (iii) the same modification (residue 146, S to L) at the major antigenic site of VP1 (G-H loop, the 135-160 region); and (iv) specific changes for each Nr population outside the major antigenic site of VP1 at residues 46, 48 and 49 of the 40-60 region of VP1 (B-C loop). These results extend our previous work on selection of Nr variants using polyclonal sera, and add new information with regard to antigenic variation, mainly concerning the involvement of the 40-60 region of VP1 in the process of immune selection.

Social networks and daily activities of street youth in Belo Horizonte, Brazil. Street Youth Study Group

Social networks and daily activities of children and adolescents living and/or working on the streets of a large Brazilian city were examined. Drawing on data collected through structured surveys, in-depth interviews, focus group discussions, and field observations, we described street youths' family situation, social resources, institutional experiences, survival activities, and problem behaviors and investigated differences attributable to age, gender, and living situation (at home or on the street). Youngsters who lived at home and worked on the street appeared to be experiencing orderly development despite their impoverished circumstances. Youngsters who lived on the street showed hallmarks of psychological and physical risk, including parental loss, diminished social support, substance abuse, and early onset of sexual activity. Possible implications of these contextual differences for development are discussed, and directions for future research are suggested.

Low flow veno-venous ECMO: an experimental study

Clinical use of extracorporeal membrane oxygenation (ECMO) and carbon dioxide removal (ECCO 2R) have become well established techniques for the treatment of severe respiratory failure; however they require full cardiopulmonary bypass, representing major procedures with high morbidity. We theorized the possibility of an efficient low flow veno-venous extracorporeal membrane gas exchange method. Four mongrel 12 kg dogs were submitted to veno-venous extracorporeal membrane gas exchange via a jugular dialysis catheter using a low flow (10 ml/min) roller pump and a membrane oxygenator for a period of four hours. Respiratory rate was set at 4 breaths/min with a FiO 2 of 21% and ventilatory dead space was increased. Adequate gas exchange was obtained (pO 2139, pCO 224, Sat 99.4%), without major hemodynamic changes or hematuria. Our results demonstrate the feasibility of a low flow, less aggressive system. Further research should be considered.

Evaluation of the clinical usefulness of APACHE II and SAPS systems in the initial prognostic classification of acute pancreatitis: a multicenter study

The clinical usefulness of the APACHE II and SAPS systems in the early prognostic classification of patients with acute pancreatitis has been evaluated in a prospective multicenter study. We aimed to identify early those patients with acute pancreatitis who should be monitored closely to expedite the detection and treatment of complications. One hundred eighty-two patients with acute pancreatitis were included; 28 were classified as severe, having developed at least one major complication of the disease. The scores obtained through the APACHE II and SAPS systems in these severe cases were significantly higher than the scores in the mild cases of acute pancreatitis (p < 0.001). The sensitivity of these systems in the prognostic classification of acute pancreatitis was 70.4% for APACHE II and 66.7% for SAPS, and the specificity was 79.1% for both. When applying APACHE II and SAPS systems in the early phase of acute pancreatitis, the possibility of misdiagnosing the severity exists, thus limiting the application of these systems in the initial assessment of prognostic classification. In conclusion, APACHE II and SAPS systems are of limited clinical utility in the early prognostic evaluation of acute pancreatitis because of their low positive predictive value.

[Anxiety scales and Goldberg's depression: an efficient interview guide for the detection of psychologic distress]

OBJECTIVES

Validation of Goldberg's Anxiety and Depression scales in our settings.

DESIGN

Transverse study. Two phases screening at population previously stratified and randomly allocated. SITE. National Health Institute's Primary Care Centres at the city of Zaragoza.

PATIENTS AND OTHER PARTICIPANTS

444 patients, aged 19 and older, who attend their general practitioner for a new episode of illness. The sample has been previously stratified by sex and age.

MEASUREMENTS AND MAIN RESULTS

At the first stage the sample has been studied with a Health Survey consisting of a variety of sound validity (General Health Questionnaire-28 items version, spanish version of Folstein's mini Mental Status Examination, CAGE and another drug and over the counter products screening questionnaire) and the new scales, that we attempt to validate. At the second stage "the possible cases" chosen at the first phase and 10% of possible non cases are assessed with a comprehensive Psychiatric Interview: EPEP (Standardized Polyvalent Psychiatric Interview).

CONCLUSIONS

The new scales E.A.D.G. have supported their validity for the screening of the most prevalent psychiatric disturbances in primary care settings. Their validity for the screening of the most prevalent psychiatric disturbances in primary care settings. They have outstanding and promising advantages when compared to traditional methods: brevity, simplicity, discriminatory ability between anxiety and depression and usefulness as an interview guideline.

Sexual practices and attitudes of street youth in Belo Horizonte, Brazil. Street Youth Study Group

Street youth are at risk of HIV infection worldwide. To develop effective prevention strategies, information about the meanings and functions of sexual activity for street youth is needed. In this paper, data from structured questionnaires, focus group discussions, in-depth interviews and field observations are used to build up a picture of the sexual culture of 9-to-18-year-olds living and/or working on the streets of a large Brazilian city. The findings reveal that these children and adolescents engage in sexual behavior that puts them at risk of sexually transmitted diseases, including HIV/AIDS, and reinforce that sex is a multi-determined and entrenched behavior in this population. Interventions must take into account the fact that for street youth, sex is used as a means of ensuring survival, seeking comfort, finding pleasure, and dealing with psychological issues that arise during adolescence.

A new interview for the multiaxial assessment of psychiatric morbidity in medical settings

A new semistructured instrument, the Standardized Polyvalent Psychiatric Interview or SPPI has been developed primarily for assessing medical patients. It has been built on the Clinical Interview Schedule and is intended to evaluate individuals in a multiaxial schema: psychopathology, including duration and severity of disorder; somatic disturbance; social problems and social supports: and pre-morbid personality, with special emphasis on 'neuroticism'. The SPPI generates enough information to allow the use of different research diagnostic criteria, including DSM-III-R, ICD-10 and Goldberg's criteria of 'attribution' of somatic symptoms and 'relationships between psychiatric and physical disorder'. It also includes a section related to recommended treatment. The new interview fulfils standards of feasibility, face and content validity. An incomplete block design, inter-rater reliability study was carried out with a consecutive sample of 48 out-patients referred to the Psychosomatic-Liaison Service of the University Hospital of Zaragoza. A broad range of agreement coefficients were calculated, the results being quite acceptable (most kappas are in the range from 0.7 to 0.9) and tending to support the procedural validity of the interview.

Different glutathione redox status and lipid peroxidation in the cortex and the medulla of the rat kidney subjected to ischemia-reperfusion stress

When the rat kidney is subjected to ischemia and reperfusion, changes in glutathione content and in lipid peroxidation are produced in the cortex and in the medulla. The cortex shows a decrease in the glutathione content and a higher sensitivity to development of lipid peroxidation, the medulla being less affected. Reperfusion restores the glutathione concentration of the cortex during the first hours of reflow. The lipid peroxidation observed in the cortex and the medulla during reperfusion is higher than in ischemia. The protective role of glutathione and the response of the cortex and the medulla to ischemia-reperfusion injury are discussed.

[Effect of quinolones on mice experimental infection by Plasmodium berghei and their possible therapeutic usefulness]

The search for new antimalarial drugs is important for many reasons, specially because of the resistance of plasmodia. Some clinical and laboratory studies have recently indicated that quinolones, currently in use for treatment of bacterial infections, have antimalarial activity. So, we evaluated the possible action of ciprofloxacin, norfloxacin, ofloxacin and pefloxacin in mice experimentally infected by Plasmodium berghei, by the oral route. Taking into account parasitemia and mortality, we came to conclusion that these drugs are not effective, as judged by the methods used.

Changes in the xanthine dehydrogenase/xanthine oxidase ratio in the rat kidney subjected to ischemia-reperfusion stress: preventive effect of some flavonoids

The enzyme xanthine oxidase has been implicated in the tissue oxidative injury after ischemia-reperfusion. This enzyme, which is a source of oxygen free radicals, is formed from a dehydrogenase form during ischemia. The ratio dehydrogenase/oxidase of rat kidney homogenates decreases during the ischemia and the reperfusion. Two flavonoids, quercetin and silybin, characterized as free radical scavengers, exert a protective effect preventing the decrease in the dehydrogenase/oxidase ratio observed during ischemia-reperfusion. The mechanism of this effect and the role of flavonoids in the ischemia-reperfusion tissue damage is discussed.