A longitudinal cohort study to identify prognostic factors associated with outcome in primary care attendees with unexplained physical symptoms
Physical symptoms which lack a diagnosis or explanation even after appropriate investigation are extremely common in primary care. These can be described as ‘unexplained physical symptoms’ (UPS) and are a significant problem; distressing for patients, difficult for doctors to manage and cost the UK economy up to £18 billion a year. However, knowledge about outcome of patients with UPS over time in primary care is limited.
The aim of this study was to investigate prognostic factors associated with outcome of primary care attendees with UPS. Adult attendees (>=18 years) from nine general practices in socio-economically diverse locations were screened using the somatic symptom module of the Patient Health Questionnaire (PHQ-15). Eligible respondents (i.e. those with UPS and a PHQ-15 score >=5) were invited to take part in the longitudinal study. The baseline questionnaire enquired about a number of potential prognostic factors including: socio-demographic characteristics, quality of life, psychological well-being, childhood experiences (family health, traumatic experiences and abuse), past and present stressful experiences and self-efficacy. Health service use data were collected using electronic medical records. Descriptive analyses were used to determine whether symptoms had resolved, were still under investigation, were diagnosed, or were still unexplained at follow-up. Multivariable regression analysis identified baseline associations with primary outcome somatic symptom severity at 6 months.
294 participants (231 females, median age 44 years (IQR 32, 57)) had a mean baseline PHQ-15 score of 11 (SD = 12) At 6 months 245 (83%) participants were followed up; the mean PHQ-15 score was 11 (SD 5) and 55% reported that their symptoms were still unexplained. Only 11% reported that their symptoms had resolved, 24% had received a diagnosis and 42% were still under investigation (options were not mutually exclusive). Significant predictors of increasing symptom severity at follow up included female gender (B=1.31 95% CI 0.12 to 2.50), higher symptom severity at baseline (B=0.53 95% CI 0.42 to 0.64), experience of childhood physical abuse (B=1.86 95% CI 0.27 to 3.45), perception of doing badly financially (B=1.90 95% CI 0.89 to 2.91) and lower physical functioning (B= -0.10 95% CI -0.15 to -0.04). Age showed no significant association when adjusted for other variables (B=0.01 95% CI -0.03 to 0.04).
This study has found that UPS are likely to persist over six months amongst those with multiple symptoms, therefore, it is important to develop appropriate services to identify and meet the needs of these primary care attendees. Future work may explore the potential use of the prognostic factors identified in this study to develop clinical prognostic tools for use by general practitioners as well as to inform the development of management strategies for those with UPS.