Medically unexplained symptoms: An epidemiological study in seven specialities

https://doi.org/10.1016/S0022-3999(01)00223-9Get rights and content

Abstract

Objectives: This study aimed to estimate the prevalence and risk factors for medically unexplained symptoms across a variety of specialities. Methods: A cross-sectional survey was conducted at two general hospitals in southeast London between 1995 and 1997. Eight hundred and ninety consecutive new patients from seven outpatient clinics were included. Demographic and clinical characteristic variables were assessed. Results: Five hundred eighty-two (65%) of the subjects surveyed returned completed questionnaires. A final diagnosis was available in 550 (62%). Two hundred twenty-eight (52%) fulfilled criteria for medically unexplained symptoms. The highest prevalence was in the gynecology clinic (66%). After adjustment for confounders, medically unexplained symptoms were associated with being female, younger, and currently employed. Psychiatric morbidity per se was not associated with the presence of medically unexplained symptoms, but was more likely in those complaining of multiple symptoms. Those with medically unexplained symptoms were less disabled, but more likely to use alternative treatment in comparison with those whose symptoms were medically explained. Patients with medically unexplained symptoms were more likely to attribute their illness to physical causes as opposed to lifestyle factors. Conclusions: Medically unexplained symptoms are common across general/internal medicine and represent the most common diagnosis in some specialities. Medical behavior, training, and management need to take this into account.

Introduction

Medically unexplained symptoms are a common problem across general medicine. They can be presentations of recognized psychiatric disorders such as anxiety or depression; a part of operationally defined unexplained syndromes such as chronic fatigue syndrome, irritable bowel syndrome, or fibromyalgia; or simply exist as symptoms in the absence of a defined organic diagnosis. Medically unexplained symptoms are an important problem in general medicine not only because of their prevalence but also on account of the high associated consumption of health service resources.

Medically unexplained symptoms are reported to be more common among women, younger age groups, and those from lower socioeconomic backgrounds [1], [2], [3], [4], [5], [6], [7], and are associated with the presence of psychiatric disorders [8], [9]. Those without conventional medical explanation for their symptoms are about twice as likely to fulfill criteria for psychiatric disorders [10]. Another study of specialist care showed the number of lifetime somatic symptoms was significantly and positively related to the increase in the number of current and past episodes of anxiety and depression [11]. Kisely et al. [12] also found that the presence of somatic symptoms, whether medically explained or unexplained, was associated with psychiatric morbidity.

Many questions about medically unexplained symptoms remain unanswered. Most studies have taken place in one or only a few clinics; the number of variables under study have been limited; and researchers often tend to concentrate on single specific symptoms or syndromes as opposed to looking at medically unexplained symptoms as a whole. Most research has focussed on variables such as demographic factors and psychiatric morbidity. Other variables such as illness cognitions and the social consequences of the illness have tended to be ignored.

We conducted a cross-sectional study of medically unexplained symptoms in the general hospital, which included the principal medical specialities and used the same assessment across all settings. In this paper, we report the prevalence and associations of medically unexplained symptoms in general hospital outpatients.

Section snippets

Sample

Consecutive new patients residing in southeast London and referred by their general practitioners to outpatient clinics at King's College and Dulwich Hospitals between 1995 and 1997 were recruited. The clinics were gastroenterology, gynecology, neurology, rheumatology, chest, cardiology, and dentistry. Subjects were eligible for inclusion if they were aged between 16 and 65 years. Subjects who could not read or speak English; and those with psychotic illnesses or organic brain syndromes were

Baseline characteristics

During the period of the study, 890 new patients attended the seven clinics. A total of 582 valid responses were obtained (65%). There was a significant association between clinics and response rate (P=.01). The dental clinic had the highest response rate (75%) while gastroenterology had the lowest (55%). Nonresponders did not differ from responders in terms of ethnicity. However, responders were more likely to be female (62% responders vs. 53% nonresponders, P=.02) and older (mean=43.2,

Comment

Medically unexplained symptoms were defined as current somatic complaints reported by patients, for which conventional biomedical explanation could not be found on routine examination or investigations, rated 3 months after the initial appointment. Previous studies have rated symptoms as medically explained/unexplained on either patient self-report or the clinician's impression on the initial visit [1], [17], [18]. In this study, medically unexplained symptoms were judged as present on the

Acknowledgements

Dr. Nimnuan is supported by Thai government as a part of a PhD program. We are particularly grateful to the following consultants who allow access to their clinics: Dr. W. Gardner, Dr. I. Forgacs, Dr. M. Blott, Dr. D. Scott, Prof. N. Johnson, Dr. C. Pankhurst, Dr. T. Britton, Dr. D. Jewitt, Prof. J. Moxham. We thank all patients and medical staff who took part.

References (27)

  • IA Canino et al.

    Functional somatic symptoms: a cross ethnic comparison

    Am J Orthopsychiatry

    (1992)
  • J Robbins et al.

    Cognitive and social factors in somatization

  • GR Smith et al.

    Patients with multiple unexplained symptoms: their characteristics, functional health and health care utilization

    Arch Intern Med

    (1986)
  • Cited by (425)

    View all citing articles on Scopus
    View full text