La SEP en Haute-Garonne : une sous-estimation importante du nombre de cas

Performance of administrative databases for identifying individuals with multiple sclerosis

Administrative databases are an alternative to disease registries as a research tool to study multiple sclerosis. However, they are not initially designed to fulfill research purposes. Therefore, an evaluation of their performance is necessary. Our objective was to assess the performance of the French administrative database comprising hospital discharge records and national health insurance databases in identifying individuals with multiple sclerosis, in comparison with a registry that exhaustively compiles resident multiple sclerosis cases in Lorraine, northeastern France, as reference. We recorded all individuals residing in the Lorraine region who were identified by the administrative database or the registry as having multiple sclerosis from 2011 to 2016. We calculated the Matthews correlation coefficient and other concordance indicators. For identifying individuals with multiple sclerosis, the Matthews correlation coefficient by the administrative database was 0.79 (95% CI 0.78-0.80), reflecting moderate performance. The mean time to identification was 5.5 years earlier with the registry than the administrative database. Administrative databases, although useful to study multiple sclerosis, should be used with caution because results of studies based on them may be biased. Our study highlights the value of regional registries that allow for a more exhaustive and rapid identification of cases.

Prevalence and mortality of patients with multiple sclerosis in France in 2012: a study based on French health insurance data

Data on the prevalence of multiple sclerosis (MS) in France are scarce. National and regional updated estimates are needed to better plan health policies. In this nationwide study, we provided estimates of the prevalence of MS in France in 2012 and mortality rate in 2013. MS cases were identified in the French national health insurance database (SNIIRAM-PMSI) using reimbursement data for disease-modifying treatment, long-term disease status for MS, disability pension for MS, and hospitalisation for MS (MS ICD-10 code: G35). We identified 99,123 MS cases, corresponding to an overall crude prevalence rate of 151.2 per 100,000 inhabitants [95% confidence interval (CI) 150.3-152.2]: 210.0 per 100,000 in women (95% CI 208.4-211.5) and 88.7 per 100,000 in men (95% CI 87.6-89.7). The overall prevalence rate was 155.6 per 100,000 inhabitants (95% CI 154.7-156.6) after standardization on the 2013-European population. We observed a prevalence gradient with a higher prevalence (190-200 per 100,000) in North-Eastern France and a lower prevalence in Southern and Western France (126-140). The crude mortality rate in 2013 was 13.7 per 1,000 MS cases (11.4 in women and 20.3 in men). The standardized mortality ratio was 2.56 (95% CI 2.41-2.72). Our results revise upwards the estimation of MS prevalence in France and confirm the excess mortality of MS patients compared to the general population.

[Identification of neurodegenerative diseases in administrative databases in France: A systematic review of the literature]

BACKGROUND

Given the health, social and economic burden of neurodegenerative diseases (ND), the development of epidemiologic studies is required. Administrative databases, such as the French national health insurance database (SNIIRAM) could represent an opportunity for researchers. ND could be presumed from drug reimbursement data, hospital stays or registration of a chronic condition. The aim of this study was to describe, in French administrative databases, algorithms used to identify Alzheimer's disease and associated disorders (ADAD), Parkinson's disease and associated disorders (PDAD), multiple sclerosis (MS), and amyotrophic lateral sclerosis (ALS).

METHODS

A systematic literature review was performed in Medline and gray literature through December 31th, 2015. French studies focusing on ADAD, PDAD, MS or ALS as a primary health outcome, conducted among one of the SNIIRAM data sources (outpatient reimbursements, chronic condition registration, hospital discharge) were included.

RESULTS

Thirty-four studies were included (ADAD, n=18, PDAD, n=9, MS, n=4, ALS, n=3), leading to 36 algorithms. For each studied ND, there was an important variability in the algorithms, concerning (i) the type of criteria used (administrative database versus multi-source systems); (ii) the number of criteria used; (iii) the definition used for each criteria. The extent and level of drug exposure highly varied. Identification through hospitalizations showed variations in terms of type of stay (short stay, long-term stay, psychiatric ward…), extent of diagnosis codes used, diagnosis type (principal, related, associated diagnosis) and period used. A validation study was conducted for 2 out of 36 algorithms (PDAD), and criteria completeness was estimated for 3 algorithms (MS, ALS).

CONCLUSION

Despite the increase in ND identification among French administrative databases, few algorithms have been validated. Validation studies should be encouraged.

Geographical Heterogeneity of Multiple Sclerosis Prevalence in France

Introduction

Geographical variation in the prevalence of multiple sclerosis (MS) is controversial. Heterogeneity is important to acknowledge to adapt the provision of care within the healthcare system. We aimed to investigate differences in prevalence of MS in departments in the French territory.

Methods

We estimated MS prevalence on October 31, 2004 in 21 administrative departments in France (22% of the metropolitan departments) by using multiple data sources: the main French health insurance systems, neurologist networks devoted to MS and the Technical Information Agency of Hospitalization. We used a spatial Bayesian approach based on estimating the number of MS cases from 2005 and 2008 capture–recapture studies to analyze differences in prevalence.

Results

The age- and sex-standardized prevalence of MS per 100,000 inhabitants ranged from 68.1 (95% credible interval 54.6, 84.4) in Hautes-Pyrénées (southwest France) to 296.5 (258.8, 338.9) in Moselle (northeast France). The greatest prevalence was in the northeast departments, and the other departments showed great variability.

Discussion

By combining multiple data sources into a spatial Bayesian model, we found heterogeneity in MS prevalence among the 21 departments of France, some with higher prevalence than anticipated from previous publications. No clear explanation related to health insurance coverage and hospital facilities can be advanced. Population migration, socioeconomic status of the population studied and environmental effects are suspected.

Geographic variations of multiple sclerosis prevalence in France: The latitude gradient is not uniform depending on the socioeconomic status of the studied population

Background

In France, two studies analysed multiple sclerosis prevalence nationwide: one was carried out in farmers, and the other one in employees. A south-north gradient of prevalence was found solely in farmers.

Objective

In order to better describe the latitude gradient in France, which is not uniform depending on the studied population, we assessed whether a gradient exists in another population than farmers and employees: independent workers. The same methods of case ascertainment have been used.

Methods

Altogether 4,165,903 persons insured by the French health insurance scheme for independent workers were included. We searched the database for (a) long term disease status ‘multiple sclerosis’, (b) domicile, (c) gender and (d) age.

Results

A total of 4182 cases of multiple sclerosis were registered giving a prevalence of 100.39/100,000. Adjustment by age and sex and spatial smoothing with a Bayesian analysis showed a gradual increase of prevalence from the southwest to the northeast of France. Standardised morbidity ratio was correlated with latitude and longitude (p<0.0001; p = 0.0031; adjusted R²= 0.3038).

Conclusion

A discrepancy of geographic distribution between farmers and independent workers on the one hand and employees on the other cannot be attributable to environment. Assuming that socioeconomic status by itself is not associated with multiple sclerosis risk, employees’ geographic mobility at adulthood for professional reasons could have interfered with the gradient effect.

Sex and age differences in ED patients with mental and behavioral disorders due to psychoactive substance use

OBJECTIVES

The objectives of this study are to describe an emergency department (ED) adult population with the chief complaint of mental and behavioral disorders due to psychoactive substance use and to investigate sex- and age-related differences.

METHODS

We analyzed data (2009-2011) from the Regional Observatory of Emergency Medicine ORU-MiP (700000 patients per year) for all patients with a primary diagnosis of mental and behavioral disorders due to psychoactive substance use. Day data were weighted by the number of days in the year and expressed for 100000 inhabitants of the area. Pearson χ(2) test and Fisher tests were used. The Brown-Mood test was used to compare medians.

RESULTS

Of the 1411597 ED visits analyzed, 20838 consults (1.3%) were for primary diagnosis of mental and behavioral disorders due to psychoactive substance use. The median age (interquartile range) was 41 (28-51) years; 69.5% were men. More women consulted the ED for sedative or hypnotic use (4.9% vs 1.5%, P < 10(-4)) than men, and more men consulted for alcohol consumption (93.5% vs 90%, P < 10(-4)) and cannabinoids (1.4% vs 1.0%, P < 10(-3)) than women. Young consumer visits dramatically increased during weekends (average of 88 visits a day per 100000 inhabitants vs 34 on Mondays to Thursdays). Another difference was found between young adults and middle-aged adults, with a peak in visits at 2 am and 9 pm respectively.

CONCLUSIONS

Mental and behavioral disorders due to psychoactive substance use account for 1.3% of ED visits. Older people should be screened for chronic alcohol consumption. Our findings underscore the opportunity provided by the ED for screening and brief intervention in drug- and alcohol-related problems.

Incidence of multiple sclerosis in Northern Lisbon, Portugal: 1998-2007

Background

There are few, recent, well assessed, multiple sclerosis (MS) incidence surveys on European populations. This study sought to measure MS incidence in a Northern Lisbon population and assess it using capture-recapture methods (CRMs).

Methods

Among the population residing in the Northern Lisbon Health Area, registered MS diagnoses were obtained from general practitioners in three primary-care districts covering a population of 196,300, and a neurology unit at the main referral hospital. Cases with onset during the periods 1978–1997 and 2008–2012 were excluded due to perceived poor access to image-supported neurological diagnosis and administrative changes in patient referral respectively. Age- and sex-specific incidences for the period 1998–2007 were calculated using McDonald diagnostic criteria, and CRMs were used to correct age-specific incidence rates. The corrected figures were also adjusted for age using the European Standard Population as reference.

Results

When applied to 62 MS patients with onset in the period 1998–2007, the rates per 100,000 population were as follows for both sexes: crude, 3.16; age-adjusted, 3.09 (95% CI 2.32 to 3.87); CRM-adjusted, 4.53 (95% CI 3.13 to 5.94); and age- and CRM-adjusted, 4.48 (3.54-5.41). In general, the rates were 3-fold higher among women than among men. Negative source dependency and CRM impact were highest at ages 35–44 years, where a 60% rise led to a peak incidence.

Conclusions

MS incidence in Northern Lisbon, Portugal, is moderately lower than that yielded by surveys on European populations. CRMs, which in this instance suggest undercounts, are a potentially useful tool for case-finding assessment but their application may introduce bias.

Is it time for a new global classification of multiple sclerosis?

BACKGROUND

The geographic distribution of multiple sclerosis (MS) is classically divided into three zones based on frequency that were established by Kurtzke in the early 1970s. In recent years, an increasing number of epidemiological studies have shown significantly higher MS prevalence and incidence rates.

OBJECTIVE

The aim of this study was to review and update the geographic distribution of MS using incidence, prevalence and disease duration from the latest epidemiology surveys.

METHODS

We conducted a systematic review of articles on MS epidemiology published between January 1, 1990 and December 31, 2012.

RESULTS

MS studies were grouped by continent: the Americas, Europe, Asia, Australia/New Zealand, and Africa. A total of 101 studies were identified according to the inclusion criteria, and 58 reported incidence estimates. Globally, the median estimated incidence of MS was 5.2 (range: 0.5-20.6) per 100,000 p-yrs, the median estimated prevalence of MS was 112.0 (with a range of 5.2-335) per 100,000 p-yrs, and the average disease duration was 20.2 years (range: 7.6-36.2).

CONCLUSION

In the past few decades, the global prevalence and incidence patterns of MS have changed dramatically. Regardless of the reason of increasing prevalence and incidence rate, we suggest the need for a novel classification system based on global MS disease burden. Adopting such a system would improve economic efficiency and prioritization in health policy planning for MS.

Incidence and prevalence of multiple sclerosis in Europe: a systematic review

BACKGROUND

Multiple sclerosis (MS) is the most common cause of neurological disability in young adults worldwide and approximately half of those affected are in Europe. The assessment of differential incidence and prevalence across populations can reveal spatial, temporal and demographic patterns which are important for identifying genetic and environmental factors contributing to MS. However, study methodologies vary and the quality of the methods can influence the estimates. This study aimed to systematically review European studies of incidence and prevalence of MS and to provide a quantitative assessment of their methodological quality.

METHODS

A comprehensive literature search was performed to obtain all original population-based studies of MS incidence and prevalence in European populations conducted and published between January 1985 and January 2011. Only peer-reviewed full-text articles published in English or French were included. All abstracts were screened for eligibility and two trained reviewers abstracted the data and graded the quality of each study using a tool specifically designed for this study.

RESULTS

There were 123 studies that met the inclusion criteria. The study estimates were highly heterogeneous, even within regions or countries. Quality was generally higher in the more recent studies, which also tended to use current diagnostic criteria. Prevalence and incidence estimates tended to be higher in the more recent studies and were higher in the Nordic countries and in northern regions of the British Isles. With rare exceptions, prevalence and incidence estimates were higher in women with ratios as high as 3:1. Few studies examined ethnicity. Epidemiological data at the national level was uncommon and there were marked geographical disparities in available data, with large areas of Europe unrepresented and other regions well-represented in the literature. Only 37% of the studies provided standardized estimates.

CONCLUSIONS

Despite the breadth of the literature on the epidemiology of MS in Europe, inter-study comparisons are hampered by the lack of standardization. Further research should focus on regions not yet studied and the evaluation of ethnic differences in MS prevalence and incidence. National-level studies using current diagnostic criteria, validated case definitions and similar age- and sex-standardization would allow better geographical comparisons.

Estimating the prevalence and incidence of multiple sclerosis in the Lorraine region, France, by the capture–recapture method

Objective:

The objective of this study was to assess the prevalence and incidence of multiple sclerosis (MS) in the Lorraine region, in France.

Methods:

Data from three sources – Regional Health Insurance System, medical records departments and the Lorraine registry of MS – and a capture–recapture method with log-linear models were used to estimate the prevalence and incidence of MS.

Results:

We identified 7193 records of reported MS corresponding to 4299 unique suspected cases of MS existing on 31 December 2008, in Lorraine. On the basis of the 4001 validated cases, the observed crude prevalence of MS was 170.9 cases per 100,000 inhabitants (95% confidence interval [CI]: 165.7; 176.3), and the observed annual crude incidence of MS was 4.4 cases per 100,000 inhabitants (95% CI: 3.6; 5.4). With the capture–recapture method, the estimated prevalence of MS was 4405.7 (95% CI: 4261.5; 4629.7), so an estimated 405 cases were not identified by the three sources. The estimated prevalence was 188.2 cases per 100,000 inhabitants (95% CI: 182.7; 193.8), and the estimated annual incidence was 8.5 cases per 100,000 inhabitants (95% CI: 7.3; 9.7).

Conclusions:

The capture–recapture method allowed us to estimate an additional 10.1% of unobserved prevalent cases and to anticipate 47.5% of unobserved incident cases.

National estimate of multiple sclerosis incidence in France (2001–2007)

Background:

In France, the incidence of multiple sclerosis (MS) is not well known, and MS is one of the 30 long-term illnesses for which patients are covered for 100% of their health care costs.

Objective:

To estimate the incidence of MS in France and its geographic variations.

Methods:

We estimated the national rate for notification of MS to the main French health insurance system, and its confidence interval (CI), between November 2000 and October 2007, which covers 87% of the population. We analysed geographic variations using a Bayesian approach.

Results:

Between November 2000 and October 2007, among a covered population of 52,449,871, some 28,682 individuals were registered as having MS. After age standardization according to the European population, the notification rate for MS was 6.8 per 100,000 (6.7–6.9), 9.8 (9.7–10.0) in women and 3.7 (3.6–3.8) in men. When the under-notification rate (11.5% and 29%) was taken into account, the notification rate per 100,000 inhabitants was estimated between 7.6 and 8.8. The notification rate was higher in north-eastern France, and lower on the Atlantic coast and in the Alps as well as on both sides of the Rhône River.

Conclusions:

This study, conducted on a representative French population, provides for the first time national estimates of MS incidence between November 2000 and October 2007.

Multiple sclerosis prevalence in Malaga, Southern Spain estimated by the capture–recapture method

Background: Although not definitively proven, there is commonly accepted to be a latitudinal gradient in the distribution of multiple sclerosis (MS), which is more frequent in temperate zones. The European Mediterranean countries are situated in a zone of median frequency, although ever increasing figures have been noted in the last decades.

Objective: The objective of this study was to assess the current prevalence rate of MS in the province of Malaga, Southern Spain.

Methods: The capture–recapture method (CRM) uses independent sources of data and permits the number of non-registered cases of a given disease to be estimated, and by doing so, to avoid ascertainment bias.

Results: Use of this method showed the estimated prevalence rate of MS in the province of Malaga, Southern Spain, to be 125/105 (95% confidence interval: 102/105–169/105), higher than the figures published previously.

Conclusions: Although we recognize that these data need to be confirmed in further studies and in other areas of the country using a similar method, we believe this study is the first to find such high figure of prevalence, being very similar to the figures reported in recent years in other southern European countries.