Background: This systematic literature review of the epidemiology of Guillain-Barré syndrome (GBS) identifies trends in incidence rates by age, study method and cause of disease. It is important to have a reliable estimate of incidence to determine and investigate any changes: no previous systematic reviews of GBS have been found. Methods: After critical assessment of the reliability of the reported data, incidence rates were extracted from all relevant papers published between 1980 and 2008, identified through searches of Medline, Embase and Science Direct. Results: Sixty-three papers were included in this review; these studies were prospective, retrospective reviews of medical records or retrospective database studies. Ten studies reported on the incidence in children (0–15 years old), and found the annual incidence to be between 0.34 and 1.34/100,000. Most studies investigated populations in Europe and North America and reported similar annual incidence rates, i.e. between 0.84 and 1.91/100,000. A decrease in incidence over the time between the 1980s and 1990s was found. Up to 70% of cases of GBS were caused by antecedent infections. Conclusions: Our best estimate of the overall incidence of GBS was between 1.1/100,000/year and 1.8/100,000/year. The incidence of GBS increased with age after 50 years from 1.7/100,000/year to 3.3/100,000/year.

Objective To determine the value of patient-reported symptoms in diagnosing endometriosis.Design A national case-control study.Setting Data from the UK General Practice Research Database for years 1992-2001.Sample A total of 5540 women aged 15-55 years, diagnosed with endometriosis, each matched to four controls without endometriosis.Methods Data were analysed to determine whether specific symptoms were highly indicative of endometriosis. Odds ratios for these symptoms were derived by conditional logistic regression analysis. . Women with endometriosis were also found to consult the doctor more frequently than the controls and were twice as likely to have time off work.Conclusions Specific symptoms and frequent medical consultation are associated with endometriosis and appear useful in the diagnosis. Endometriosis may coexist with or be misdiagnosed as pelvic inflammatory disease or IBS.

Objective  To investigate whether the increased chances of having a diagnosis of irritable bowel syndrome (IBS) and pelvic inflammatory disease (PID) in women with endometriosis is due to misdiagnosis or co‐morbidity.Design  A case–control study of women aged 15–55 years with endometriosis and matched controls.Setting  Data from the UK’s General Practice Research Database for the years 1992–2001.Sample  A total of 5540 women aged 15–55 years, diagnosed with endometriosis, each matched to four controls without endometriosis. The index date was defined as the date of diagnosis.Methods  Data were analysed to determine whether women with endometriosis were more likely to receive a diagnosis of PIDor IBS than women without endometriosis. Odds ratios were calculated for endometriosis associated with IBS and PID before and after the index date.Main outcome measures  Diagnosis of IBS or PID before and after the index date.Results  Compared with the controls, women with endometriosis were 3.5 times more likely to have received a diagnosis of IBS (OR 3.5 [95% CI: 3.1–3.9]). Even after women had been diagnosed with endometriosis, they were still two and a half times more likely to receive a new diagnosis of IBS when compared with the controls (OR 2.5 [95% CI: 2.2–2.8]). Similarly, women with endometriosis were more likely than those without endometriosis to have been treated for PID both before (OR 5.9 [95% CI: 5.1–6.9]) and after (OR 3.8 [95% CI: 3.1–4.6]) being diagnosed with endometriosis.Conclusions  Women with endometriosis are more likely to be diagnosed with IBS and PID than controls, even after a definitive diagnosis of endometriosis has been reached.