The prevalence of multiple sclerosis (MS) in Oceania, a systematic review, and meta-analysis

BACKGROUND

Oceania is a continent, covering more than 8 million km2, with a population of more than 44 million people. In different countries landing in Oceania, various prevalence of MS has been reported, so we designed this systematic review and meta-analysis to estimate the pooled prevalence of MS in Oceania.

METHODS

We systematically searched PubMed, Scopus, EMBASE, Web of Science, and Google Scholar. We also searched references of included studies, and conference abstracts. The search was done on January 1, 2023, by two independent researchers. We extracted the name of the first author, country, publication year, prevalence period, number of study participants, total female and male population, disease duration, type of MS, mean duration of the disease, mean age at disease onset, mean Expanded Disability Status Scale (EDSS), and total female and male patients with MS.

RESULTS

A literature search revealed 81,044 records; after deleting duplicates, 38,260 records remained. One hundred and six full texts were evaluated, and finally, seventeen studies remained for systematic review. Most studies were done in Newcastle; eight studies were done in 1961, 8 in 1981, 2 in 1996, and 2 in 2001. In all other years, only one study was done. The pooled prevalence of MS in 1961 in Oceania was estimated as 19.85/100,000 (I2=70.3%, p=0.001). The pooled prevalence of MS in 1981 in Oceania was estimated as 39.07/100,000 (I2 =88%, p=0.001).

CONCLUSIONS

The result of this systematic review and meta-analysis shows that the prevalence of MS has increased dramatically during the timespan in Oceania.

Epidemiological study of multiple sclerosis in Illawarra region

BACKGROUND

Multiple sclerosis (MS) is an autoimmune inflammatory demyelinating disease which causes significant disabilities. Latest MS epidemiological data in Australia reveals rising prevalence. No epidemiological study of MS has been conducted so far in the Illawarra region.

AIM

To calculate prevalence and incidence of MS in the Illawarra and compare with other regions', states' and national prevalence data.

METHOD

Data of MS patients in the Illawarra were collected from hospital medical records, ambulatory care units and hospital pharmacy. Prevalence was calculated for alive MS patients on June 30, 2018 expressed per 100 000 population. Yearly adjusted incidence rate was calculated for 10 years (2009-2019), expressed as cases per 100 000 population-years.

RESULTS

Estimated MS prevalence in the Illawarra was 116.6 per 100 000 population with yearly incidence (2009-2019) of 5.06 cases per 100 000 population-years (female to male, 3:1). Relapsing-remitting MS (RRMS) was the most common type (277/397 ~ 69.7%) with primary progressive MS (PPMS) in 52/397 ~ 13%, and secondary progressive MS (SPMS) in 45/397 ~ 11.3% (unknown in 23). Commonest age at diagnosis ranged between 30-39 years for all types with RRMS and PPMS between 30-39 years and 40-49 years respectively. The most commonly recorded treatment was natalizumab (103 patients) followed by fingolimod (82 patients) and interferon (58 patients).

CONCLUSION

The calculated MS prevalence in the Illawarra is higher than NSW and Australian average MS prevalence. Further epidemiological studies focusing on MS risk factors and other factors bearing on MS prevalence in the Illawarra are required. This article is protected by copyright. All rights reserved.

Multiple sclerosis epidemiology in Asia and Oceania; A systematic review and meta-analysis

BACKGROUND

Multiple sclerosis (MS) is an inflammatory demyelinating CNS disease and the most common neurological immune-mediated disorder. Due to its progressive format, it affects patients' quality of life (QoL) significantly. This study aimed to evaluate epidemiologic parameters of MS in the Asia and Oceania continents.

METHODS

A comprehensive literature search on October 1st, 2020, was performed in PubMed, Scopus, and Web of Science to retrieve original population-based studies on MS epidemiology in the Asian and Oceanian countries, published between January 1st, 1985 and October 1st, 2020. The designed search strategy was repeated for each country, and the relevant referenced articles were added to our database. A random-effect model was used to combine the epidemiological estimates, and subgroup analysis was also performed by continent, region, and country, when possible. Meta-regression analysis was done to evaluate the effects of Human Developmental Index (HDI), latitude, and study period on the epidemiologic parameters.

RESULTS

A total of 3,109 publications were found, of which 89 articles met the eligibility criteria and were included for data extraction. These articles provided data on prevalence, incidence, and mean age at disease onset in 18 countries in Asia and Oceania, including Iran, Turkey, Cyprus, Kuwait, Saudi Arabia, Qatar, UAE, Jordan, Israel, India, Malaysia, China, Hong Kong, Taiwan, Republic of Korea, Japan, Australia, and New Zealand. The pooled total prevalence, incidence, and mean age of onset in Asia and Oceania were 37.89/100000 (95% CI: 35.65 - 40.142), 2.40/100000 (95% CI: 2.22 - 2.58), and 28.21 (95% CI: 27.55 - 28.88), respectively. MS prevalence and incidence in the female gender (68.7/100000 and 4.42/100000, respectively) were infinitely higher than in the male gender (24.52/100000 and 2.06/100000, respectively). Our subgroup analysis showed that MS was much more prevalent in Australia and West Asia among the studied area. The meta-regression showed that the total incidence decreased with an increase in the HDI, and the total prevalence in Asia increased with increasing latitude gradients. Also, the study period had a positive effect on the total prevalence and incidence in Asia and Oceania.

CONCLUSION

MS prevalence and incidence have increased in recent decades. This study highlights the need for further studies to elucidate MS's geographical and temporal variations' exact etiologies.

Estimating the prevalence and incidence of treated type 2 diabetes using prescription data as a proxy: A stepwise approach on Iranian data

AIMS

Type 2 diabetes is a serious health challenge, and large-scale studies on its prevalence in Iran are lacking. In pharmacoepidemiology, case-finding can be done by reviewing the prescription databases for specific drug(s) prescribed for a disease. We aimed to determine the prevalence and incidence of type 2 diabetes in Fars province, Iran, using prescription data and a stepwise approach to ascertain the results.

METHODS

A dataset of 3,113 insured individuals aged ≥35 years were selected. Their Prescription Data Centre records were reviewed for all drugs frequently used in controlling type 2 diabetes available in the Iranian pharmacopeia. Then we used a stepwise method for case-finding. In step one, each individual with a positive drug history for type 2 diabetes was labeled as an individual with diabetes. The next two steps were implemented for ascertainment of step one estimations.

RESULTS

Prevalence of type 2 diabetes based on prescription, internist opinion, and phone call verification in 2015 and 2016 was 9.3% and 10.3%, 8.5% and 9.8%, and 7.2% and 8.7%, respectively. An incidence of 1.9% was determined for 2016.

CONCLUSIONS

We obtained a realistic estimation of prevalence and incidence of treated type 2 diabetes, using prescription data which are large-scale, low cost, and real-time.

Use of geographical information systems in multiple sclerosis research: A systematic scoping review

INTRODUCTION

Geographical information system (GIS) and spatial analysis have an emerging role in the understanding and management of health-related outcomes. However, there is a knowledge gap about the extent to which GIS has supported multiple Sclerosis (MS) research. Therefore, this review aimed to explore the types of GIS applications and the complexity of their visualisation in MS research.

METHODS

A systematic scoping review was conducted based on York's five-stage framework. PubMed, Scopus and Web of Science were searched for relevant studies published between 2000 and 2020 using a comprehensive search strategy based on the main concepts related to GIS and MS. Grounded, inductive analysis was conducted to organize studies into meaningful application areas. Further, we developed a tool to assess the visualisation complexity of the selected papers.

RESULTS

Of 3,723 identified unique citations, 42 papers met our inclusion criteria for the final review. One or more of the following types of GIS applications were reported by these studies: (a) thematic mapping (37 papers); (b) spatial cluster detection (16 papers); (c) risk factors detection (16 papers); and (d) health access and planning (two papers). In the majority of studies (88%), the score of visualisation complexity was relatively low: three or less from the range of zero to six.

CONCLUSIONS

Although the number of studies using GIS techniques has dramatically increased in the last decade, the use of GIS in the areas of MS access and planning is still under-researched. Additionally, the capacity of GIS in visualising complex nature of MS care system is not yet fully investigated.

Disease modifying therapies for relapsing-remitting multiple sclerosis: Use and costs in Australia (1996-2019)

BACKGROUND

New disease modifying therapies (DMT) to control relapsing-remitting multiple sclerosis (RRMS) have been introduced to the market in the past few years and are now widely used in Australia.

OBJECTIVE

To analyse the dispensed use of government subsidised RRMS DMTs in Australia from 1996 to 2019.

METHODS

We obtained data of dispensed use of DMTs from the Australian Government's Pharmaceutical Benefits Scheme (PBS) administered by Medicare Australia. We measured use as defined daily dose (DDD) per 100,000 population per day. We obtained jurisdictional population data from the Australian Bureau of Statistics.

RESULTS

Total DMT use increased by an average of 18% annually, from 2.4 (in 1996) to 69.9 DDD/100,000/day in 2019. Interferon β1B was the most commonly used medicine between 1996 and 2000, Interferon β1A between 2001 and 2014, and fingolimod subsequently. Among Australian states, Tasmania (the southernmost state) had the highest dispensed DMT use of 94.6 DDD/100,000/day in 2019. Concession beneficiaries under the Government's PBS had both lower use and cost per patient than general beneficiaries did. Fingolimod and ocrelizumab accounted for 55% of total expenditure on MS drug therapy in 2019.

CONCLUSION

The use of oral DMTs might increasingly replace parenteral treatments in the near future. Given the current substantial government expenditure on oral DMTs, it will be imperative to examine the real world effectiveness of DMTs.

Change in multiple sclerosis prevalence over time in Australia 2010–2017 utilising disease-modifying therapy prescription data

Objective:

Determine the prevalence of multiple sclerosis (MS) in Australia in 2017 using MS-specific disease-modifying therapy (DMT) prescription data and estimate the change in prevalence from 2010.

Methods:

DMT prescriptions were extracted from Australia’s Pharmaceutical Benefits Scheme (PBS) data for January–December 2017. Percentages of people with MS using DMTs (DMT penetrance) were calculated using data from the Australian MS Longitudinal Study. Prevalence was estimated by dividing the total number of monthly prescriptions by 12 (except alemtuzumab), adjusted for DMT penetrance and Australian population estimates. Prevalences in Australian states/territories were age-standardised to the Australian population. Comparisons with 2010 prevalence data were performed using Poisson regression.

Results:

Overall DMT penetrance was 64%, and the number of people with MS in Australia in 2017 was 25,607 (95% confidence interval (CI): 24,874–26,478), a significant increase of 4324 people since 2010 ( p < 0.001). The prevalence increased significantly from 95.6/100,000 (2010) to 103.7/100,000 (2017), with estimates highest in Tasmania in 2017 (138.7/100,000; 95% CI: 137.2–140.1) and lowest in Queensland (74.6/100,000; 95% CI: 73.5–75.6). From 2010 to 2017 using the median latitudes for each state/territory, the overall latitudinal variation in MS prevalence was an increase of 3.0% per degree-latitude.

Conclusion:

Consistent with global trends, Australia’s MS prevalence has increased; this probably reflecting decreased mortality, increased longevity and increased incidence.

Identifying incident cancer cases in dispensing claims: A validation study using Australia's Repatriation Pharmaceutical Benefits Scheme (PBS) data

Introduction

Dispensing claims are used commonly as proxy measures in pharmacoepidemiological studies; however, their validity is often untested.

Objectives

To assess the performance of a proxy for identifying cancer cases based on the dispensing of anticancer medicines and estimate the misclassification of cancer status and potential for bias researchers may encounter when using this proxy.

Methods

We conducted our validation study using Department of Veterans’ Affairs (DVA) client data linked with the New South Wales (NSW) Cancer Registry and Repatriation Pharmaceutical Benefits Scheme data. We included DVA clients aged ≥65 years residing in NSW between July 2004 and December 2012. We matched clients with a cancer diagnosis to clients without a diagnosis based on demographic characteristics and available observation time. We used dispensing claims for anticancer medicines dispensed between July 2004 and December 2013 as a proxy to identify clients with cancer and calculated sensitivity, specificity, positive predictive values and negative predictive values compared with cancer registrations (gold standard), overall and by cancer site. We illustrated misclassification by the proxy in a cohort of people initiating opioid therapy. Using the proxy, we excluded people with cancer from the cohort, in an attempt to delineate people potentially using opioids for cancer rather than chronic non-cancer pain.

Results

We identified 15,679 new cancer diagnoses in 14,112 DVA clients from the cancer registry and 62,663 clients without a diagnosis. Sensitivity of the proxy based on dispensing claims was 30% for all cancers and around 20% for specific cancers (range: 10-67%). Specificity was above 90% for all cancers. The dispensing proxy correctly identified 26% of people with a cancer diagnosis who initiated opioid therapy and failed to identify 74% those with a cancer diagnosis; the proxy was most robust for clients with breast cancer where 61% were correctly identified by proxy.

Conclusions

Using dispensing of anticancer medicines to identify people with a cancer diagnosis performed poorly. Excluding patients with evidence of anticancer medicine use from cohort studies may result removal of a disproportionate number of women with breast cancer. Researchers excluding or otherwise using anticancer medicine dispensing to identify people with cancer in pharmacoepidemiological studies should acknowledge the potential biases introduced to their findings.

Keywords

cancer, diagnosis, proxy, dispensing records, validation study

Oral health and behaviours of people living with Multiple Sclerosis in Australia

OBJECTIVES

The literature describing the oral health of people with Multiple Sclerosis (MS) is scant and the findings equivocal. The aim of this study was to describe the oral health and oral self-care behaviours of people living with MS and compare it to the Australian population.

METHODS

Participants enrolled with the Australian MS Longitudinal Study (AMSLS) were invited to participate in the survey using an online or paper-based questionnaire. Data were collected on level of disability, oral health, oral self-care and factors influencing attendance for oral health care.

RESULTS

Completed questionnaires were received for 1523 respondents. Over one-fifth (n = 320; 22%) rated their oral health as fair or poor, and more than half (n = 840; 57%) reported toothache in the last 12 months. These proportions were higher than those for the general Australian adult population (oral health prevalence ratio (PR) = 1.25 [1.12, 1.40]; toothache PR = 3.63 [3.39, 3.88]), and this is despite comparable or better self-maintenance habits and dental attendance reported by respondents. People with MS reported high rates of mouth dryness (68.4%), teeth sensitivity (64.7%), change of taste (40.5%) and orofacial pain (39.0%); fewer than 10% experienced none of these. There was a lower prevalence of self-reported need for treatment (extraction or filling) than in the Australian adult population (15.8% vs 32.9%).

CONCLUSIONS

People with MS have a greater oral health burden, demonstrated by their poorer self-reported oral health than the Australian adult population. Furthermore, they experience high rates of toothache, mouth dryness, teeth sensitivity, change of taste and orofacial pain. These findings are contrary to their self-reported good oral self-care and dental attendance habits and suggest some of the oral health impacts are due to MS rather than dental behaviours.

Effectiveness of Exercise Interventions for Pain Reduction in People With Multiple Sclerosis: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

To systematically review the evidence of the effect of exercise compared with passive control on pain in people with multiple sclerosis.

DATA SOURCE AND STUDY SELECTION

Five electronic databases were searched for randomized controlled trials published up to March 2017 that recruited people with multiple sclerosis where exercise was the intervention and pain was an outcome (PROSPERO registration number CRD42017060489).

STATISTICAL ANALYSIS

A random-effects meta-analysis was conducted to estimate the standardized mean difference of the effect of exercise on pain between treatment and control groups. We assessed risk of bias, fitted meta-regression models to explore heterogeneity between studies, and assessed small study effects.

DATA SYNTHESIS

Ten studies met the inclusion criteria (total sample size=389), and all studies were at high risk of bias. We found that exercise interventions were associated with less pain compared with passive control groups (standardized mean difference=-.46; 95% CI, -.92 to .00). There was high between-study heterogeneity (I²=77.0%), which was not explained by the prespecified study characteristics. There was also some evidence of small study effects.

CONCLUSION

This is the first systematic review of the effect of exercise interventions on pain in people with multiple sclerosis, a chronic neurological disorder that affects 2.5 million people. We found some evidence that exercise compared with passive control alleviates pain in this population, but there were limitations in reporting and study quality with high risk of bias of individual studies and heterogeneity between studies.

Multiple Sclerosis impact on employment and income in New Zealand

BACKGROUND AND OBJECTIVES

We investigated the demographic, social and clinical characteristics associated with employment status and income for people with multiple sclerosis (MS) in New Zealand (NZ).

METHODS

The NZ National MS Prevalence study included all persons resident in NZ on census day 2006 diagnosed with MS (96.7% coverage). Factors associated with employment and income status among the working age population (25-64 years) were identified by linear regression.

RESULTS

Over 90% of working age people with MS (n=1727) had a work history, but 54% were not working. Work loss occurred early in the disease course, and at low disability (P<.001). Advancing age, progressive disease, longer disease duration, higher disability levels, partner loss and lower education were associated with work loss (P<.001). Working age people with MS had lower income than the NZ population (P<.0001). Higher qualifications yielded no additional income for MS females and about half the additional income for MS males (P<.0001).

CONCLUSIONS

MS profoundly reduces employment and income early in the disease course, and at low levels of disability, however, unemployment is not entirely accounted for by clinical, social and demographic factors. These findings suggest social supports should be explored early in the disease course to reduce loss of income and unemployment for people with MS.

Correlation of geographic distributions of haptoglobin alleles with prevalence of multiple sclerosis (MS) - a narrative literature review

We have proposed that the myelin damage observed in multiple sclerosis (MS) may be partly mediated through the long-term release and degradation of extracellular hemoglobin (Hb) and the products of its oxidative degradation [Cellular and Molecular Life Sciences, 71, 1789-1798, 2014]. The protein haptoglobin (Hpt) binds extracellular Hb as a first line of defense, and can serve as a vascular antioxidant. Humans have two different Hpt alleles: Hpt1 and Hpt2, giving either homozygous Hpt1-1 or Hpt2-2 phenotypes, or a heterozygous Hpt1-2 phenotype. We questioned whether those geographic regions with higher frequency of the Hpt2 allele (conversely, lower frequency of Hpt1 allele) would correlate with an increased incidence of MS, because different Hpt phenotypes will have variable anti-oxidative potentials in protecting myelin from damage inflicted by extracellular Hb and its degradation products. To test this hypothesis, we undertook a systematic analysis of the literature on reported geographic distributions of Hpt alleles to compare them with data reported in the World Health Organization Atlas of worldwide MS prevalence. We found the frequency of the Hpt1 allele to be low in European and North American countries with a high prevalence of MS, consistent with our hypothesis. However, this correlation was not observed in China and India, countries with the lowest Hpt1 frequencies, yet low reported prevalence of MS. Nevertheless, this work shows the need for continued refinement of geographic patterns of MS prevalence, including data on ethnic or racial origin, and for new clinical studies to probe the observed correlation and evaluate Hpt phenotype as a predictor of disease variability and progression, severity, and/or comorbidity with cardiovascular disorders.

Prevalence of multiple sclerosis in the Lazio region, Italy: use of an algorithm based on health information systems

Compared with other areas of the country, very limited data are available on multiple sclerosis (MS) prevalence in Central Italy. We aimed to estimate MS prevalence in the Lazio region and its geographical distribution using regional health information systems (HIS). To identify MS cases we used data from drug prescription, hospital discharge and ticket exemption registries. Crude, age- and gender-specific prevalence estimates on December 31, 2011 were calculated. To compare MS prevalence between different areas within the region, we calculated age- and gender-adjusted prevalence and prevalence ratios using a multivariate Poisson regression model. Crude prevalence rate was 130.5/100,000 (95 % CI 127.5–133.5): 89.7/100,000 for males and 167.9/100,000 for females. The overall prevalence rate standardized to the European Standard Population was 119.6/100,000 (95 % CI 116.8–122.4). We observed significant differences in MS prevalence within the region, with estimates ranging from 96.3 (95 % CI 86.4–107.3) for Latina to 169.6 (95 % CI 147.6–194.9) for Rieti. Most districts close to the coast showed lower prevalence estimates compared to those situated in the eastern mountainous area of the region. In conclusion, this study produced a MS prevalence estimate at regional level using population-based health administrative databases. Our results showed the Lazio region is a high-risk area for MS, although with an uneven geographical distribution. While some limitations must be considered including possible prevalence underestimation, HIS represent a valuable source of information to measure the burden of SM, useful for epidemiological surveillance and healthcare planning.

Physical activity and associated levels of disability and quality of life in people with multiple sclerosis: a large international survey

BACKGROUND

Multiple Sclerosis (MS) is a common neurodegenerative disease, which often has a devastating effect on physical and emotional wellbeing of people with MS (PwMS). Several studies have shown positive effects of physical activity (PA) on disability, health related quality of life (HRQOL), and other outcomes. However, many studies include only people with mild disability making it difficult to generalize findings to those with moderate or severe disability. This study investigated the associations between PA and HRQOL, relapse rate (RR), disability, and demographic variables in PwMS with varying disability.

METHODS

Through online platforms this large international survey recruited 2232 participants with MS who completed items regarding PA, MS and other health characteristics.

RESULTS

PwMS who were younger (p < .001), male (p = 0.006), and with lower body mass index (BMI) (p < .001) undertook more PA, which was associated with decreased disability (p < 0.001) and increased HRQOL measures (all p < 0.001). For the subsample of people with relapsing-remitting MS, PA was associated with a decreased RR (p = 0.009). Regression analyses showed that increased PA predicted clinically significant improvements in HRQOL while controlling for level of disability, age and gender. More specifically, increasing from low to moderate and to high PA increased estimated mean physical health composite from 47.7 to 56.0 to 59.9 respectively (25.6% change), mental health composite from 60.6 to 67.0 to 68.8 (13.5% change), energy subscale from 35.9 to 44.5 to 49.8 (38.7% change), social function subscale from 57.8 to 66.1 to 68.4 (18.3% change), and overall QOL subscale from 58.5 to 64.5 to 67.7 (15.7% change).

CONCLUSIONS

For PwMS, regardless of disability level, increased PA is related to better HRQOL in terms of energy, social functioning, mental and physical health. These are important findings that should be taken into consideration by clinicians treating PwMS.

Notes on the epidemiology of multiple sclerosis, with special reference to dietary habits

A hypothesis, based primarily on the occurrence of multiple sclerosis (MS) in the Faroe Islands and supported by numerous analytical epidemiological studies, is described. It proposes that MS is caused by the interaction of a virus disease with intestinal pathology, e.g., infectious mononucleosis, and application of smoked and nitrate/nitrite-cured meat products in the diet during circumscribed time intervals. The biological mechanisms might involve a break of tolerance by an alteration of self within the central nervous system, by nitrophenylated compounds conjugated to animal tissue, in particular to proteins occurring in the central nervous system. Further research is needed.

Increasing prevalence and incidence rates of multiple sclerosis in Kuwait

Background:

Kuwait was considered as low to intermediate risk area for MS.

Objectives:

To determine the prevalence and incidence rates of MS among Kuwaiti nationals based on 2011 population census.

Methods:

This cross-sectional study was conducted between October 2010 and April 2013 using the newly developed national MS registry in Kuwait. Patients with a diagnosis of MS according to 2010 revised McDonald criteria were identified. The crude, age- and sex-specific prevalence and incidence rates among Kuwaiti patients were calculated.

Results:

1176 MS patients were identified of which 927 (78.8%) were Kuwaitis and 249 (21.2%) were expatriates. Among Kuwaiti patients, female to male ratio was 1.8:1 with a mean age of 35.40 ± 10.99 years. The prevalence rate of MS was 85.05 per 100,000 persons (95% CI: 82.80 – 87.04). There was a peak in prevalence among patients aged 30–39 years. The incidence of MS was 6.88 per 100,000 persons (95% CI 5.52–8.55). Between 2003 and 2011, the incidence increased 3.22 and 2.54 times in women and men respectively.

Conclusion:

Kuwait is considered a high-risk area for MS. The significant increase in prevalence and incidence rates may represent a true increase despite the improvement in case ascertainment and case definition.