G.-X. Jiang

Elevated Suicide Risk among Patients with Multiple Sclerosis in Sweden

Results from previous studies of suicide risk among patients with multiple sclerosis (MS) are inconsistent. This may be explained partly by differences in methodology and study populations. The purpose of our study was to investigate suicide risk among hospital patients with MS in Sweden. During the period 1969–1996, 12,834 cases were recorded in the Swedish Hospital Inpatient Register, with 77,377 hospital admissions, in which MS was a primary or secondary diagnosis at discharge. The mean follow-up time for the whole cohort was 9.9 (SD 7.3) years. When the data for these MS patients were linked to the Swedish Causes of Death Register for the same period, 5,052 (39.4%) were found to have died. Among the 5,052 deaths, suicide was an underlying cause of death in 90 cases (1.8%). The mean period between the initial admission date with an MS diagnosis at discharge and the date of death for the 90 MS suicide cases was 5.8 (SD 5.1) years. This was significantly shorter (p = 0.002) than the mean of 7.9 (SD 6.4) years for MS cases who died due to other causes. Suicide risk, calculated as the standardized mortality ratio (SMR), was significantly elevated (SMR = 2.3) among both male and female MS cases compared with the general population. Suicide risk was particularly high in the first year after initial admission with an MS diagnosis, and among younger male MS cases. The mean age at the time of suicide was 44.5 (SD 12.4) years, and 58% of the suicides were committed within 5 years after the first admission with an MS diagnosis. The crude suicide rate among MS patients during the study period was 71 per 100,000 person-years. The rate was significantly higher (p < 0.001) in males (114) than in females (47), with an odds ratio of 2.4 (95% CI: 1.6–3.8). These findings have implications for suicide preventive measures in neurological practice.

Clinical epidemiology of Guillain–Barré syndrome in adults in Sweden 1996–97: a prospective study

We described clinical manifestations, outcomes, prognostic indicators and clinico‐epidemiological subgroups for 53 adult patients with Guillain–Barré syndrome (GBS) in Sweden during the period 1996–97. These patients were identified from a population of 2.8 million inhabitants and prospectively followed up for one year by a network of neurologists. An additional 10 cases, of whom five were adults who had not been prospectively followed up, were not included in the analyses. At 6 months after onset 80% of the patients could walk without aid, while at 1 year 46% were fully recovered, 42% had mild residual signs or symptoms, 4% had moderate and 6% severe disabilities, and 2% had died. Intravenous human immunoglobulin or plasmapheresis were used in 72% of the patients. The sum of the Medical Research Council (MRC) score at nadir was found as the only significant predictor for residual signs at 1 year in a multivariate model. Three subgroups, with different clinico‐epidemiological characteristics, were identified by using cluster analysis. In conclusion, GBS in Sweden is frequently preceded by a respiratory infection, is often treated with immunomodulatory therapies, and exhibits a high recovery rate and a low fatality rate.

Epidemiological features of Guillain-Barré syndrome in Sweden, 1978-93.

OBJECTIVES: To describe the incidence of Guillain-Barré syndrome in Sweden during the period 1978-93 and its temporal and geographical variations. METHODS: Stratified and Poisson regression analyses and tests for detection of small epidemics were applied to population based hospital discharge data from 2257 incident cases of Guillain-Barré syndrome in Sweden during the study period. RESULTS: The incidence of Guillain-Barré syndrome was (1) 1.77 per 100000 person-years when age adjusted to the European population; (2) higher in males; and (3) stable across time, although occasional increases of annual incidence rates were found-namely, in 1978 (relative risk (RR) 1.30 (95% CI 1.10-1.54)), and in 1983 (RR 1.24 (95% CI 1.06-1.40)). The incidence increased with age and was bimodal, with peaks at 20-24 and 70-74 years. There was a moderate but significant seasonality with a peak in August, particularly among the young age groups. The age adjusted incidence by county varied from 1.11 to 2.57 per 100000 person-years. Neither temporal nor spatial clustering was significant, except during the period July-September in 1983 at ages below 40 years. CONCLUSIONS: The incidence of Guillain-Barré syndrome in Sweden during the period 1978-93 had a magnitude similar to those described in other surveys, a bimodal distribution by age, and modest geographical and temporal variations with significantly high rates in 1978 and 1983 and in autumn. Minor outbreaks might have passed unnoticed up to the present. Whereas reported drug induced cases of Guillain-Barré syndrome may in part explain the high incidence in 1983, the cause of the aberrant incidence in 1978 remains unknown. Epidemiological surveillance of Guillain-Barré syndrome in Sweden might have been useful.

Guillain-Barré syndrome in South-West Stockholm, 1973–1991, 1. Quality of registered hospital diagnoses and incidence

We describe the incidence and explore the quality of registered diagnosis for Guillain‐Barré syndrome (GBS) in a population‐based retrospective study in South‐West Stockholm (SWS), Sweden, during the period 1973–1991. We used data on registered hospital discharges and open‐care visits, and from medical records. Medical records were available for 83 (80.6%) of 103 patients with registered GBS diagnosis at discharge from hospitals. For 69 (83.1%) of such patients, the information from the hospital record fulfilled the National Institute of Neurological and Communicative Disorders and Stroke (NINCDS) clinical criteria for GBS. One out‐patient presented with suspected GBS. In contrast, none of 40 patients discharged with diagnosis of unspecific polyneuropathy fulfilled the above mentioned criteria. During the period 1973–1991, the mean annual incidence of GB S per 100000 was 1.74, 95% CI 1.41–2.12, from register data and 1.49, 95% CI 1.19–1.85, after excluding those not fulfilling criteria for GBS. The age‐adjusted incidence after validation was higher for men, 1.64, 95% CI 1.19–2.21, than for women, 1.46, 95% CI 1.05–1.99. An increasing incidence with age was found, presenting the age‐specific curve a bimodal shape. The results of this study confirm that hospital discharge diagnostic data in Sweden can be used for purposes of epidemiological research and surveillance for GBS, and show that the incidence of GBS in SWS compares to those described in other populations.

Distinct pattern of age-specific incidence of Guillain-Barré syndrome in Harbin, China.

Abstract We describe the age- and sex-specific incidence of Guillain-Barré syndrome (GBS) in Harbin, China, based on the information from a prospective survey among a well-defined large population during one year. A network of physicians reported incident patients with a GBS diagnosis from a general population of 5.4 million inhabitants in Harbin, China, during the period from 1 October 1997 to 30 September 1998. Each reported patient was examined by senior neurologists and the GBS diagnosis was validated according to standard diagnostic criteria. All GBS patients were followed-up for six months after onset. Admission registers at all hospitals in Harbin were also checked afterwards for screening patients with a GBS diagnosis who might have been missed. During the study period, 79 patients with a GBS diagnosis were reported. After validation, the GBS diagnosis was confirmed in 70 patients. Another GBS patient was found through the screening of admission registers at hospitals. Among them, 36 GBS patients were residents in Harbin and the other 35 patients were from geographical areas out of Harbin. The GBS incidence, age-adjusted to the European standard population, was 0.66 (95 % CI 0.46–0.91) per 100,000 person-years, with a male to female ratio of 1.4. The highest GBS incidence was found in the youngest age-group and the incidence among the elderly was remarkably lower than those reported from other populations in Western countries. Possible explanations for the distinct pattern of age-specific incidence of GBS are discussed. Further studies are needed.

Increased incidence of Guillain-Barré syndrome postpartum

We studied the relation between pregnancy and Guillain-Barré syndrome in the Swedish female population ages 15–49 years during the period 1978–1993. Person-based information from the national Hospital In-patient Registry on patients discharged with a diagnosis of Guillain-Barré syndrome was linked to data on pregnancy and delivery from the Swedish Medical Birth Registry. We validated coded Guillain-Barré syndrome diagnoses and the time periods of clinical onset for patients hospitalized with Guillain-Barré syndrome during pregnancy or during the first 90-day postpartum period. We compared the incidence of Guillain-Barré syndrome in women in different exposure categories related to pregnancy with that in women neither pregnant nor in the 90-day postpartum period. Poisson regression analysis yielded age-adjusted rate ratios of 0.89 [95% confidence interval (CI) = 0.52–1.53] for pregnant women, 1.37 (95% CI = 0.64–2.91) for women during the first 90 days, and 2.93 (95% CI = 1.20–7.11) during the first 30 days after delivery. Our results indicate that the risk of Guillain-Barré syndrome increases after delivery, particularly during the first 2 weeks postpartum. (Epidemiology 1998; 9:601–604)

Incidence of Guillain-Barré syndrome in Sweden 1996.

We describe the incidence of Guillain‐Barré syndrome (GBS) in Sweden in 1996. Information of incident GBS patients was mainly collected by a multicentre network of 18 neurologists prospectively monitoring a general population with 4.48 million inhabitants across the country and complemented with data from the national hospital in‐patient registry. GBS diagnoses for all patients were validated by neurologists. While 53 patients with GBS were identified by the network neurologists from the study population, the other 20 GBS patients were recognized after carefully reviewing the registered data. There were 44 (60%) male patients and 29 (40%) female patients and the mean age at onset for all patients was 48.6 (SD 24.3) years. The GBS incidence, age‐adjusted to the European standard population, was 1.51 (95% CI 1.18–1.90) per 100 000 person‐years in 1996, higher in males and increased with age. When compared with selected studies, the GBS incidence in Sweden is moderately high, and the variation of GBS incidence in Europe seems to be small.

Pregnancy and Guillain-Barré syndrome: a nationwide register cohort study.

In this study, we determined the relationship between Guillain-Barré syndrome (GBS) and pregnancy. By taking advantage of several nationwide registers and the availability of personal identification numbers, we calculated person-years for Swedish females aged 15-49 years in the following categories: (1) neither pregnant nor postpartum; (2) pregnant; (3) in the first month postpartum, or (4) in the first 3 months postpartum during 1973-1983. For these women, we determined the corresponding exposure status of hospital-registered GBS cases. Medical records were examined for GBS cases hospitalized during the 2-week period postpartum and 1-month period after the last menstruation. Poisson regression analysis yielded age-adjusted relative risks (RRs) of 0.86 (95% CI 0.40-1.84) for pregnant women, and 1.47 (0.54-3.99) and 2.21 (0.55-8.94) for females during the 3-month and the 30-day period after delivery. The risk for GBS seems to be lower during pregnancy and increases after delivery.

Prospective study of clinical epidemiology of Guillain–Barré syndrome in Harbin, China

Clinical manifestations, outcomes, prognostic indicators, and clinico-epidemiological subgroups were described based on the information of 71 patients with Guillain-Barré syndrome (GBS), who were identified from a prospective survey in Harbin, China during a 1-year period from 1 October 1997 to 30 September 1998. GBS diagnoses of the patients were validated by senior neurologists and most patients were followed up for 6 months after onset. Antecedent events, mainly respiratory infections, were found in 55 (78%) patients during the month before onset. The clinical features, like motor weakness as initial symptoms (82%) and tendon areflexia or hyporeflexia (100%), are similar to those reported from other populations. However, the proportion (70%) of patients reaching to nadir less than 7 days after onset was rather high. Intravenous human immunoglobulin and/or plasmapheresis were used in 45% of the patients and steroids in 58%. At 6 months after onset, 82% of the patients could walk without aid, 46% of the patients had no any residual signs. Four (6%) patients died within 1 month due to respiratory failure. Three subgroups with different clinico-epidemiological characteristics were identified by using cluster analysis. In conclusion, GBS patients in Harbin, China were younger, had shorter time to nadir, frequently preceded by a respiratory infection, and often treated with steroids. Clinical and epidemiological differences of GBS might exist between various populations.

Guillain-Barré syndrome in South-West Stockholm, 1973-1991, 3. Clinicoepidemiological subgroups.

Using hierarchical cluster analysis, applied to 47 cases of Guillain‐Barre Syndrome (GBS) incident in South‐West Stockholm (SWS) during the period from January 1973 to June 1992, we identified three major clinicoepidemiological subgroups. The first subgroup, 25.5% of the cases (26.7 ± 6.7 years), recorded a peak incidence at ages 20–29 years and presented significant differences from other subgroups, a high proportion of cases with onset at low age preceded by respiratory infection (83.3%) and with normal motor conduction velocity (50.0%). Also found, were less affected biological parameters, a rapidly progressive course and independence in gait at one month after onset. A second subgroup, 27.7% of cases, was severely affected, clinically and functionally. It consisted predominantly of young individuals (22.7 ± 11.1 years), with a high incidence (69.2% of cases) in autumn. A third subgroup, comprising 40.47; of cases, was older (61.1 ± 11.0 years) and, in general, also severely affected. The incidence of this form appeared to be invariant with time.