Validity of hospital discharge diagnoses for public health surveillance of the Guillain-Barrè syndrome

Readmissions After Guillain-Barre Syndrome: Nationally Representative Data

OBJECTIVES

We aimed to obtain nationally representative data on hospital readmission rates after Guillain-Barre syndrome (GBS).

METHODS

International Classification of Disease, Ninth Revision codes from the 2013 National Readmissions Database identified adult GBS admissions, comorbidities, and readmission diagnoses. Logistic regression estimated odds ratios (ORs) for readmission.

RESULTS

Of 2109 GBS admissions identified, 20.8% were readmitted within 1 year and 12.2% within 30 days. Age did not predict readmission. Plasmapheresis use showed a nonsignificant trend toward readmission versus intravenous immunoglobulin use [OR 1.43, 95% confidence interval (CI) 1.00-2.051, P = 0.050]. Respiratory failure (OR 1.70, 95% CI 1.23-2.35, P = 0.0014), heart failure (OR 2.14, 95% CI 1.25-3.66, P = 0.0057), and renal failure (OR 2.00, 95% CI 1.20-3.32, P = 0.0078) predicted readmission. Top readmission diagnoses included GBS or chronic inflammatory demyelinating polyneuropathy (42.0%) and sepsis (3.5%).

CONCLUSIONS

One-fifth of GBS patients were readmitted within 1 year. Comorbid illnesses and respiratory complications increased a readmission risk but age did not.

Validity of Algorithms for Identification of Individuals Suffering from Chronic Noncancer Pain in Administrative Databases: A Systematic Review

BACKGROUND

Secondary analysis of health administrative databases is indispensable to enriching our understanding of health trajectories, health care utilization, and real-world risks and benefits of drugs among large populations.

OBJECTIVES

This systematic review aimed at assessing evidence about the validity of algorithms for the identification of individuals suffering from nonarthritic chronic noncancer pain (CNCP) in administrative databases.

METHODS

Studies reporting measures of diagnostic accuracy of such algorithms and published in English or French were searched in the Medline, Embase, CINAHL, AgeLine, PsycINFO, and Abstracts in Social Gerontology electronic databases without any dates of coverage restrictions up to March 1, 2018. Reference lists of included studies were also screened for additional publications.

RESULTS

Only six studies focused on commonly studied CNCP conditions and were included in the review. Some algorithms showed a ≥60% combination of sensitivity and specificity values (back pain disorders in general, fibromyalgia, low back pain, migraine, neck/back problems studied together). Only algorithms designed to identify fibromyalgia cases reached a ≥80% combination (without replication of findings in other studies/databases).

CONCLUSIONS

In summary, the present investigation informs us about the limited amount of literature available to guide and support the use of administrative databases as valid sources of data for research on CNCP. Considering the added value of such data sources, the important research gaps identified in this innovative review provide important directions for future research. The review protocol was registered with PROSPERO (CRD42018086402).

Validity of death certificates in the identification of cases of amyotrophic lateral sclerosis (ALS) in the Limousin region, France. A population-based study

Objectives: Mortality data have been used as a proxy for amyotrophic lateral sclerosis (ALS) incidence. However, the accuracy of death certificates (DCs) needs to be validated. This study aims to assess the accuracy of DCs in the identification of ALS cases. Methods: This is a retrospective population-based validation study. DC information, provided by the "Centre d'épidémiologie sur les causes médicales de décès", including ICD10 codes for specific cause of death for patients recorded in the French register of ALS cases in the Limousin region (FRALim) and deceased between 2000 and 2011, was assessed. The FRALim register was used as gold standard. Results: In the study period, DCs were available for 197 patients diagnosed with ALS, of whom 185 (93.9%) were correctly identified with an ICD10 code (G12.2) corresponding to ALS. The overall sensitivity was 93.9% (95% CI 89.6-96.8) and the positive predictive value (PPV) was 64.9 (59.1-70.4), with higher values in the period 2004-2011 (75.0-78.9). Stratification for sex, age, and year at death did not show difference in accuracy, except a lower PPV during the first years of observation. Conclusions: DCs identifying subjects with a diagnosis of ALS in the Limousin region, France showed an overall good sensitivity and moderate PPV. The absence of ALS diagnosis as the main and underlying cause of death on DCs highlights the need to use DC in combination with other administrative data to create algorithms with higher accuracy performances.

Guillain-Barré syndrome and antecedent cytomegalovirus infection, USA 2009-2015

OBJECTIVE

To describe incidence and clinical characteristics of cases of Guillain-Barré syndrome (GBS) in the USA during 2009-2015, and characteristics of GBS cases with antecedent cytomegalovirus (CMV) infection among persons with employer-sponsored insurance.

METHODS

We analyzed medical claims from IBM Watson MarketScan® databases. GBS patients were defined as enrollees with an inpatient claim with GBS as the principal diagnosis code, based on ICD-9 or ICD-10, and ≥ 1 claim for lumbar puncture or EMG/nerve conduction study. We assessed intensive care unit (ICU) hospitalization, intubation, dysautonomia, and death. We also assessed selected infectious illness within 60 days prior to the first GBS-coded inpatient claim.

RESULTS

We identified 3486 GBS patients; annual incidence was 1.0-1.2/100,000 persons during 2009-2015. GBS incidence was higher in males (1.2/100,000) than in females (0.9/100,000) (p = 0.006) and increased with age, from 0.4/100,000 in persons 0-17 years old to 2.1/100,000 in persons ≥ 65 years old (p < 0.001). Half of GBS patients were hospitalized in the ICU, 8% were intubated, 2% developed dysautonomia, and 1% died. Half had a claim for antecedent illness, but only 125 (3.5%) had a claim for specific infectious pathogens. The mean age among 18 GBS patients with antecedent CMV infection was 39 years versus 47 years among those without antecedent  CMV infection (p = 0.038).

CONCLUSIONS

Incidence of GBS using a large national claims database was comparable to that reported in the literature, but cases appeared to be less severe. Half of GBS patients reported prior infectious illness, but only a minority had a specific pathogen identified.

Incidence of Guillain-Barré Syndrome (GBS) in Latin America and the Caribbean before and during the 2015-2016 Zika virus epidemic: A systematic review and meta-analysis

Background

A severe neurological disorder, Guillain-Barré syndrome (GBS) is the leading cause of acute flaccid paralysis. Enhanced surveillance of GBS in Latin America and the Caribbean (LAC) following the 2015–2016 Zika virus (ZIKV) epidemic presents an opportunity to estimate, for the first time, the regional incidence of GBS.

Methods and findings

For this systematic review and meta-analysis, we searched nine scientific databases and grey literature from January 1, 1980 to October 1, 2018. Sources with primary data on incident GBS cases in LAC within a well-defined population and timeframe, published in English, Spanish, Portuguese, or French, were included. We calculated the annual GBS incidence rates (IRs) and 95% confidence intervals (CIs) for each source based on published data. Following an assessment of heterogeneity, we used random-effects meta-analysis to calculate the pooled annual IR of GBS. The study is registered with PROSPERO, number CRD42018086659. Of the 6568 initial citation hits, 31 were eligible for inclusion. Background annual GBS IRs in Latin America ranged from 0.40 in Brazil to 2.12/100,000 in Chile. The pooled annual IR in the Caribbean was 1.64 (95% CI 1.29–2.12, I²<0.01, p = 0.44). During the ZIKV epidemic, GBS IRs ranged from 0.62 in Mexico to 9.35/100,000 in Martinique. GBS increased 2.6 (95% CI 2.3–2.9) times during ZIKV and 1.9 (95% CI 1.1–3.4) times during chikungunya outbreaks over background rates. A limitation of this review is that the studies included employed different methodologies to find and ascertain cases of GBS, which could contribute to IR heterogeneity. In addition, it is important to consider that data on GBS are lacking for many countries in the region.

Conclusions

Background IRs of GBS appear to peak during arboviral disease outbreaks. The current review contributes to an understanding of the epidemiology of GBS in the LAC region, which can inform healthcare system planning and preparedness, particularly during arboviral epidemics.

Trial registration

Registered with PROSPERO: CRD42018086659.

A severe neurological disorder, Guillain-Barré syndrome (GBS) is the leading cause of acute flaccid paralysis. This is the first systematic review on GBS incidence in Latin America and the Caribbean before and during arboviral disease outbreaks. There is a large sub-regional and annual fluctuation in the incidence of GBS. Background annual GBS incidence rates (IRs) in Latin America ranged from 0.40 in Brazil to 2.12/100,000 in Chile. The pooled annual IR in the Caribbean was 1.64 (95% CI 1.29–2.12, I²<0.01, p = 0.44). During the ZIKV epidemic, GBS IRs ranged from 0.62 in Mexico to 9.35/100,000 in Martinique. GBS increased 2.6 times during ZIKV and 1.9 times during chikungunya outbreaks over background rates. GBS is a costly disease, which can result in long-term disability and high mortality rates in resource constrained healthcare settings. Because GBS can be triggered by arboviral infections, baseline incidence of GBS is critical for detecting neglected tropical disease outbreaks. The current review contributes to an understanding of the epidemiology of GBS in the LAC region, which can inform healthcare system planning and preparedness.

Guillain-Barré syndrome in Denmark: validation of diagnostic codes and a population-based nationwide study of the incidence in a 30-year period

Purpose: To validate the diagnostic codes for Guillain-Barré syndrome (GBS) in the Danish National Patient Registry (DNPR). Secondly, to examine 30-year trends in the incidence of GBS in Denmark. Patients and methods: We used the DNPR to identify all patients aged 16 and above diagnosed with a primary GBS diagnosis at any Danish department of neurology between 1987 and 2016. Medical files were reviewed according to the clinical criteria of the National Institute of Neurological Disorders and Stroke Committee and classified according to the Brighton criteria. The incidence rate (IR) was calculated based on data from 1987 to 2016 and stratified by season, gender, and age. Results: Over 30 years, we identified 2,319 patients aged 16 and above in the DNPR. From a validation cohort of 573 patients, we were able to retrieve 425 (74.2%) medical files; 356 GBS diagnoses were confirmed. The overall positive predictive value was 83.8% (95% confidence interval (CI): 80.0-87.0). In 99% of the confirmed patients, the Brighton criteria level 1-3 for GBS were met. The IR was fairly stable over 30 years at 1.77 per 100,000 person years (95% CI: 1.70-1.84). The incidence was higher in the winter season (IR ratio compared with summer: 1.18 (95% CI: 1.09-1.29)), and was strongly associated with male gender (IR ratio vs females: 1.44 (95% CI: 1.33-1.57)). IRs rose with age at diagnosis, particularly after the age of 50 in both men and women and a minor peak was observed for total IR in young adults. Conclusion: Primary diagnostic codes for GBS at Danish departments of neurology have high validity. The DNPR is a well-suited data source for epidemiological research on GBS. The Danish nationwide 30-year GBS IR is stable over time and similar to GBS IRs reported in other European and North American populations.

Surgery and risk of Guillain-Barré syndrome: A French nationwide epidemiologic study

OBJECTIVE

To assess the association between Guillain-Barré syndrome (GBS) and recent surgery based on French nationwide data.

METHODS

Data were extracted from the French health administrative databases (SNIIRAM/PMSI). All patients hospitalized for GBS between 2009 and 2014 were identified by ICD-10 code G61.0 as main diagnosis. Patients previously hospitalized for GBS in 2006, 2007, and 2008 were excluded. Surgical procedures were identified from the hospital database. Hospitalizations for surgery with no infection diagnosis code entered during the hospital stay were also identified. The association between GBS and a recent surgical procedure was estimated using a case-crossover design. Case and referent windows were defined as 1-60 days and 366-425 days before GBS hospitalization, respectively. Analyses were adjusted for previous episodes of gastroenteritis and respiratory tract infection, identified by drug dispensing data.

RESULTS

Of the 8,364 GBS cases included, 175 and 257 patients had undergone a surgical procedure in the referent and case windows, respectively (adjusted odds ratio [OR] = 1.53, 95% confidence interval [CI]: 1.25-1.88). A slightly weaker association was observed for surgical procedures with no identified infection during the hospitalization (OR = 1.40, 95% CI: 1.12-1.73). Regarding the type of surgery, only surgical procedures on bones and digestive organs were significantly associated with GBS (OR and 95% CI = 2.78 [1.68-4.60] and 2.36 [1.32-4.21], respectively).

CONCLUSION

In this large nationwide epidemiologic study, GBS was moderately associated with any type of recent surgery and was more strongly associated with bone and digestive organ surgery.

Appropriateness of ICD-coded Diagnostic Inpatient Hospital Discharge Data for Medical Practice Assessment

Objectives: We performed a systematic review to investigate the quality of diagnostic hospital discharge data (DHDD) in order to gain insight in the usefulness of these data for medical practice assessment. We investigated the methods used to evaluate data quality, factors that determine data quality and its consequences for medical practice assessment.

Methods: We selected studies in which both completeness (or sensitivity: SENS) and correctness (or positive predictive value: PPV) were measured. We used the random-effects model to calculate mean SENS and PPV and to explore the effect of a number of covariates.

Results: The 101 included studies were very heterogeneous. We distinguished six typical study designs. We found a mean SENS of 0.67 (95%CI: 0.62– 0.73) and PPV of 0.76 (95%CI: 0.73– 0.79); SENS was significantly lower for comorbidity and complication studies than for some single disease studies. PPV was significantly higher for Scandinavian countries than for other countries. Recoding compared to re-abstracting of the medical record as a gold standard gave a significantly lower PPV. Diagnostic data were considered appropriate by the authors of the studies for quality of care purposes when both SENS and PPV were at least 0.85. Only 13% of the studies fulfilled this criterion.

Conclusions: Variability in quality of care between settings can easily be overshadowed by variability in data quality. However, the use of DHDD by physicians to evaluate their own medical practice may be useful. But only if physicians are willing to critically interpret the meaning of the information for their medical practice assessment.

Incidence and clinical characteristics of Guillain-Barré syndrome before the introduction of Zika virus in Puerto Rico

BACKGROUND

Zika virus has been associated with increases in Guillain-Barré syndrome (GBS) incidence. A GBS incidence estimation and clinical description was performed to assess baseline GBS epidemiology before the introduction of Zika virus in Puerto Rico.

METHODS

Hospitalization administrative data from an island-wide insurance claims database and U.S. Census Bureau population estimates provided a crude GBS incidence for 2013. This estimate was adjusted using the proportion of GBS cases meeting Brighton criteria for confirmed GBS from nine reference hospitals. Characteristics of confirmed GBS cases in the same nine hospitals during 2012-2015 are described.

RESULTS

A total of 136 GBS hospitalization claims were filed in 2013 (crude GBS incidence was 3.8 per 100,000 population). The adjusted GBS incidence was 1.7 per 100,000 population. Of 67 confirmed GBS cases during 2012-2015, 66% had an antecedent illness. Median time from antecedent illness to GBS onset was 7days. Most cases (67%) occurred during July-September.

CONCLUSIONS

Puerto Rico's GBS incidence for 2013 was estimated using a combination of administrative data and medical records review; this method could be employed in other regions to monitor GBS incidence before and after the introduction of GBS infectious triggers.

Protocol for validating cardiovascular and cerebrovascular ICD-9-CM codes in healthcare administrative databases: the Umbria Data Value Project

INTRODUCTION

Administrative healthcare databases can provide a comprehensive assessment of the burden of diseases in terms of major outcomes, such as mortality, hospital readmissions and use of healthcare resources, thus providing answers to a wide spectrum of research questions. However, a crucial issue is the reliability of information gathered. Aim of this protocol is to validate International Classification of Diseases, 9th Revision-Clinical Modification (ICD-9-CM) codes for major cardiovascular diseases, including acute myocardial infarction (AMI), heart failure (HF), atrial fibrillation (AF) and stroke.

METHODS AND ANALYSIS

Data from the centralised administrative database of the entire Umbria Region (910 000 residents, located in Central Italy) will be considered. Patients with a first hospital discharge for AMI, HF, AF or stroke, between 2012 and 2014, will be identified in the administrative database using the following groups of ICD-9-CM codes located in primary position: (1) 410.x for AMI; (2) 427.31 for AF; (3) 428 for HF; (4) 433.x1, 434 (excluding 434.x0), 436 for ischaemic stroke, 430 and 431 for haemorrhagic stroke (subarachnoid haemorrhage and intracerebral haemorrhage). A random sample of cases, and of non-cases, will be selected, and the corresponding medical charts retrieved and reviewed for validation by pairs of trained, independent reviewers. For each condition considered, case adjudication of disease will be based on symptoms, laboratory and diagnostic tests, as available in medical charts. Divergences will be resolved by consensus. Sensitivity and specificity with 95% CIs will be calculated.

ETHICS AND DISSEMINATION

Research protocol has been granted approval by the Regional Ethics Committee. Study results will be disseminated widely through peer-reviewed publications and presentations at national and international conferences.

Validity of ICD-9-CM codes for breast, lung and colorectal cancers in three Italian administrative healthcare databases: a diagnostic accuracy study protocol

INTRODUCTION

Administrative healthcare databases are useful tools to study healthcare outcomes and to monitor the health status of a population. Patients with cancer can be identified through disease-specific codes, prescriptions and physician claims, but prior validation is required to achieve an accurate case definition. The objective of this protocol is to assess the accuracy of International Classification of Diseases Ninth Revision-Clinical Modification (ICD-9-CM) codes for breast, lung and colorectal cancers in identifying patients diagnosed with the relative disease in three Italian administrative databases.

METHODS AND ANALYSIS

Data from the administrative databases of Umbria Region (910,000 residents), Local Health Unit 3 of Napoli (1,170,000 residents) and Friuli--Venezia Giulia Region (1,227,000 residents) will be considered. In each administrative database, patients with the first occurrence of diagnosis of breast, lung or colorectal cancer between 2012 and 2014 will be identified using the following groups of ICD-9-CM codes in primary position: (1) 233.0 and (2) 174.x for breast cancer; (3) 162.x for lung cancer; (4) 153.x for colon cancer and (5) 154.0-154.1 and 154.8 for rectal cancer. Only incident cases will be considered, that is, excluding cases that have the same diagnosis in the 5 years (2007-2011) before the period of interest. A random sample of cases and non-cases will be selected from each administrative database and the corresponding medical charts will be assessed for validation by pairs of trained, independent reviewers. Case ascertainment within the medical charts will be based on (1) the presence of a primary nodular lesion in the breast, lung or colon-rectum, documented with imaging or endoscopy and (2) a cytological or histological documentation of cancer from a primary or metastatic site. Sensitivity and specificity with 95% CIs will be calculated.

DISSEMINATION

Study results will be disseminated widely through peer-reviewed publications and presentations at national and international conferences.

Post-licensure rapid immunization safety monitoring program (PRISM) data characterization

BACKGROUND

The Post-Licensure Rapid Immunization Safety Monitoring (PRISM) program is the immunization safety monitoring component of FDA's Mini-Sentinel project, a program to actively monitor the safety of medical products using electronic health information. FDA sought to assess the surveillance capabilities of this large claims-based distributed database for vaccine safety surveillance by characterizing the underlying data.

METHODS

We characterized data available on vaccine exposures in PRISM, estimated how much additional data was gained by matching with select state and local immunization registries, and compared vaccination coverage estimates based on PRISM data with other available data sources. We generated rates of computerized codes representing potential health outcomes relevant to vaccine safety monitoring. Standardized algorithms including ICD-9 codes, number of codes required, exclusion criteria and location of the encounter were used to obtain the background rates.

RESULTS

The majority of the vaccines routinely administered to infants, children, adolescents and adults were well captured by claims data. Immunization registry data in up to seven states comprised between 5% and 9% of data for all vaccine categories with the exception of 10% for hepatitis B and 3% and 4% for rotavirus and zoster respectively. Vaccination coverage estimates based on PRISM's computerized data were similar to but lower than coverage estimates from the National Immunization Survey and Healthcare Effectiveness Data and Information Set. For the 25 health outcomes of interest studied, the rates of potential outcomes based on ICD-9 codes were generally higher than rates described in the literature, which are typically clinically confirmed cases.

CONCLUSION

PRISM program's data on vaccine exposures and health outcomes appear complete enough to support robust safety monitoring.

Risk of Guillain-Barré syndrome after seasonal influenza vaccination and influenza health-care encounters: a self-controlled study

BACKGROUND

The possible risk of Guillain-Barré syndrome from influenza vaccines remains a potential obstacle to achieving high vaccination coverage. However, influenza infection might also be associated with Guillain-Barré syndrome. We aimed to assess the risk of Guillain-Barré syndrome after seasonal influenza vaccination and after influenza-coded health-care encounters.

METHODS

We used the self-controlled risk interval design and linked universal health-care system databases from Ontario, Canada, with data obtained between 1993 and 2011. We used physician billing claims for influenza vaccination and influenza-coded health-care encounters to ascertain exposures. Using fixed-effects conditional Poisson regression, we estimated the relative incidence of hospitalisation for primary-coded Guillain-Barré syndrome during the risk interval compared with the control interval.

FINDINGS

We identified 2831 incident admissions for Guillain-Barré syndrome; 330 received an influenza vaccine and 109 had an influenza-coded health-care encounter within 42 weeks before hospitalisation. The risk of Guillain-Barré syndrome within 6 weeks of vaccination was 52% higher than in the control interval of 9-42 weeks (relative incidence 1·52; 95% CI 1·17-1·99), with the greatest risk during weeks 2-4 after vaccination. The risk of Guillain-Barré syndrome within 6 weeks of an influenza-coded health-care encounter was greater than for vaccination (15·81; 10·28-24·32). The attributable risks were 1·03 Guillain-Barré syndrome admissions per million vaccinations, compared with 17·2 Guillain-Barré syndrome admissions per million influenza-coded health-care encounters.

INTERPRETATION

The relative and attributable risks of Guillain-Barré syndrome after seasonal influenza vaccination are lower than those after influenza illness. Patients considering immunisation should be fully informed of the risks of Guillain-Barré syndrome from both influenza vaccines and influenza illness.

FUNDING

Canadian Institutes of Health Research.

Vaccination and risk of type 1 diabetes mellitus in active component U.S. Military, 2002-2008

AIMS/HYPOTHESIS

To evaluate whether vaccination increases the risk of type 1 diabetes mellitus in active component U.S. military personnel.

METHODS

We conducted a retrospective cohort study among active component U.S. military personnel age 17-35 years. Individuals with first time diagnoses of type 1 diabetes between January 1, 2002 and December 31, 2008 were identified using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. We used Poisson regression to estimate risk ratios between individual vaccine exposures and type 1 diabetes. Secondary analyses were performed controlling for receipt of multiple vaccines and available demographic variables.

RESULTS

Our study population consisted of 2,385,102 individuals followed for approximately 7,644,098 person-years of service. This included 1074 incident type 1 diabetes cases. We observed no significant increased risk of type 1 diabetes after vaccination with anthrax vaccine adsorbed (AVA) [RR=1.00; 95% CI (0.85, 1.17)], smallpox vaccine [RR=0.84; 95% (CI 0.70, 1.01)], typhoid vaccine [RR=1.03; 95% CI (0.87, 1.22)], hepatitis B vaccine [RR=0.83; 95% CI (0.72, 0.95)], measles mumps rubella vaccine (MMR) [RR=0.71, 95% CI (0.61, 0.83)], or yellow fever vaccine [RR=0.70; 95% CI (0.59, 0.82)].

CONCLUSIONS

We did not find an increased risk of diagnosed type 1 diabetes and any of the study vaccines. We recommend that follow-up studies using medical record review to confirm case status should be considered to corroborate these findings.

Population incidence of Guillain-Barré syndrome: a systematic review and meta-analysis

Population incidence of Guillain-Barré syndrome (GBS) is required to assess changes in GBS epidemiology, but published estimates of GBS incidence vary greatly depending on case ascertainment, definitions, and sample size. We performed a meta-analysis of articles on GBS incidence by searching Medline (1966-2009), Embase (1988-2009), Cinahl (1981-2009) and CABI (1973-2009) as well as article bibliographies. We included studies from North America and Europe with at least 20 cases, and used population-based data, subject matter experts to confirm GBS diagnosis, and an accepted GBS case definition. With these data, we fitted a random-effects negative binomial regression model to estimate age-specific GBS incidence. Of 1,683 nonduplicate citations, 16 met the inclusion criteria, which produced 1,643 cases and 152.7 million person-years of follow-up. GBS incidence increased by 20% for every 10-year increase in age; the risk of GBS was higher for males than females. The regression equation for calculating the average GBS rate per 100,000 person-years as a function of age in years was exp[-12.0771 + 0.01813(age in years)] × 100,000. Our findings provide a robust estimate of background GBS incidence in Western countries. Our regression model may be used in comparable populations to estimate the background age-specific rate of GBS incidence for future studies.

Herpes zoster: Burden of disease in France

This work provides estimates of HZ incidence and HZ-related hospitalization and mortality rates in France, where no immunization programme has been implemented. Herpes zoster data was obtained from the Sentinelles surveillance general practitioners (GPs) network, the PMSI Data processing centre for hospital discharges and from the French National Mortality Database (INSERM CépiDC). The yearly HZ incidence rate averaged 382 cases per 100,000 inhabitants (95% CI 364-405) and exponentially increased with age. The annual rates of hospitalizations and mortality due to HZ varied from 4.14±0.32 to 14.42±0.39 and from 0.11±0.03 to 0.29±0.04 per 100,000 inhabitants, respectively, depending on whether HZ was coded in a 'primary' or 'primary or associated' diagnosis. One or more factors of immunodepression occurred in 43.4% of hospitalized cases and in 21.6% HZ-related deaths.

Diagnosis and treatment in inflammatory neuropathies

The inflammatory neuropathies are a large diverse group of immune-mediated neuropathies that are amenable to treatment and may be reversible. Their accurate diagnosis is essential for informing the patient of the likely course and prognosis of the disease, informing the treating physician of the appropriate therapy and informing the scientific community of the results of well-targeted, designed and performed clinical trials. With the advent of biological therapies able to manipulate the immune response more specifically, an understanding of the pathogenesis of these conditions is increasingly important. This review presents a broad overview of the pathogenesis, diagnosis and therapy of inflammatory neuropathies, concentrating on the most commonly encountered conditions.

Epidemiology of Guillain-Barré syndrome in the province of Quebec

BACKGROUND

In the province of Quebec, a population-based study of Guillain-Barré syndrome (GBS) was conducted at the time of a mass immunization campaign against meningococcal disease, in 2001.

METHODS

The study population included residents aged 2 months to 20 years observed from November 1st, 2000 to December 31, 2002, representing 4,075,465 person-years of observation. GBS cases were identified in the provincial hospital database Med-Echo and medical records were reviewed.

RESULTS

Thirty-three incident GBS cases were identified, including 27 cases of acute inflammatory demyelinating polyradiculopathy. The overall GBS incidence rate was 0.8/100,000 person-years, higher in persons aged 1 to 4 years (2.1/100,000) than in those 5 years or more (0.6/100,000). There was a female preponderance and no significant seasonal variation. All patients survived.

CONCLUSION

Results could be used to interpret reports of adverse events associated with the introduction of new vaccines in this age-group in Canada.