Current synthetic overview on spinal cord injury epidemiological data

Aim. To have updated information on the epidemiology of spinal cord injury (SCI) is required for developing an adequate and eff ective related health policy strategies and consequent contextual decisions making regarding this category of patients and also for planning and implementing SCI prevention education and measures. Accordingly, the rationale of this article is to provide a systematic overview of the literature regarding SCI epidemiology. Material and methods. We reviewed epidemiological published reports and searched on internet specifi cally databases, from diff erent centres, worldwide, about SCI, collecting descriptive data for properly estimating the incidence, prevalence, and/ or causes of SCI. Results. The global annual incidence rate is considered to be 23 cases of Traumatic Spinal Cord Injury (TSCI) per million (179,312 new cases per annum – results provided by World Health Organisation’s (WHO) in 2007). Prevalence per million inhabitants varies quite largely among statistics in diff erent countries (from 280 in Finland to 681 in Australia, 755 in the United States of America or maybe even more, and even bigger in Canada). Men more commonly suff er from this kind of pathology and the direction of SCI evolution is to have a higher cord lesion level (more tetraplegics than paraplegics) and age at injury. Conclusion. Even if the results of this literature review showed that the SCI incidence and prevalence are rising, they did not suff er signifi cant changes in the last three decades of time. The prevalence surveys remain poor, mainly because a basic requirement for having correct and appropriately updated fi gures would need national and or regional electronic dedicated registers of evidence, and this is not a situation frequent enough. But the incidence studies from USA and Europe have been increased in the last years. This article asserts the need for improving the SCI data standardised collection in many countries, especially in the ones from low developed or emergent areas.


INTRODUCTION
Spinal cord injury (SCI) is a neurological conditi on that usually determine important loss of basic functi ons (mobility, sensiti vity, micturiti on and/or defecati on control etc) (1-4) being divided in two main types of lesion i.e. complete and incomplete and having oft en devastati ng lifelong sequels. The most common severe consequences of this conditi on are complete: tetraplegia and paraplegia.
Regarding epidemiology of SCI there are considerable research works in the last 40 years (5-8) but because their important limitati ons (in durati on, not conti nuing in ti me, loss of informati on from state registries) the evaluati on of internati onal trustworthy SCI databases on incidence and (especially) prevalence became more diffi cult to be done. (9) In a short digression, we emphasize that during 2006-2008, the Neuro-Rehabilitati on Clinic Division of the Teaching Emergency Hospital "Bagdasar-Arseni" (TEHBA) led by Prof. G. Onose as Project Director, deployed and carried out an excellency scienti fi c research project enti tled "Initi ati on of a Nati onal Informati cal Network for dynamic clustering of pati ents with Spinal Cord Injury, dedicated to improve their quality of life, by aiming the efi cienti sati on of the specifi c medico-social services, in transiti on" (acronym: R.I.S.C.I. -Romanian Informati cs on SCI).
Within this project there has been achieved also a parti ally automati cally updati ng database, including by dynamic clustering. This intended nati onal database could store informati on (secured, according to actual laws); yet, although including patented by the Romanian State Offi ce for Inventi ons and Marks (registered No: RO 2011 00006 -"Interacti ve integrated system for collecti ng and managing biomedical data dedicated to advanced pati ents' dispensary") this has sti ll not been implemented, pending on approval from the Social Medical Insurance System. Consequently, although initi ati on of such a network -warmly encouraged by the Leadership of the Internati onal Spinal Cord Society (ISCoS) -through wide-spreading specifi c informati on, would hopefully contribute to improve knowledge on chronic post SCI pati ents' situati ons, we do not currently have an electronic register with such individuals. (10) The damage of the spinal cord can be done by trauma or by other causes like: degenerati ve pathology, tumours, infecti ons, multi ple sclero-sis, etc., and so, they can be split in two main categories: Traumati c Spinal Cord Injury (TSCI) and Non-Traumati c Spinal Cord Injury (NTSCI). From epidemiological point of view, the second group of such lesions, even if more frequently met, with higher incidence than TSCI, are less studied (possible because of the non-concordance on the defi niti ons of NTSCI or what pathology should be covered by such diagnosis) (9). Therefore, we will refer in this arti cle parti cularly on TSCI.

STUDY DESIGN AND AIM
Accordingly, in this work will be assessed a number of aspects regarding epidemiology (incidence, demographic aspects of these cases: age, gender, causes of injury, life expectancy, prevalence) of SCI based on a systemati c review of the specifi c literature, in order to improvebeing necessary more eff ecti ve ways -its preventi on strategies and endeavours.
An important reason to quest and know the current incidence and prevalence of SCI is connected to the bio-psychological and socio-economical impact of such devastati ng conditi ons over ti me, especially related to their irreversible consequences. (11)

MATERIAL AND METHODS
We have analyzed relevant epidemiological surveys on SCI using an extensive literature review (based on important published reports and internet sites of SCI organisati ons, Google Scholar, using a number of key words) in order to provide recent and specifi c descripti ve informati on. Incidence values may show SCI level of control, including based on a good or poor preventi on strategy and achievements. (11) An internati onal comparison survey from 1995, showed that prevalence studies are fewer than incidence ones regarding SCI (12) and the same situati on persists nowadays.
In 2005 it could be esti mated that all over the world were around 2.5 million SCI persons, with 130,000 and more, new cases reported each year. (13,14) In 2007 the overall incidence rate, worldwide, was evaluated at 23 new cases of TSCI per million yearly (179312 cases per annum) with a regional distributi on of: 40 in North America, 16 in Europe, 15 in Australia. Other regional data vary between 21-25 in Asia, between 19-25 in Lati n America and 21-29 in Africa. (15) Including in respect to SCI, the closest to reality and updated stati sti cs are to be found in the United States of America (USA) -so, we will detail here some current informati on from this zone (16). Also, it must be menti oned that, for a period of more than ten years, 1990-2000's ti ll 2010, probably because of some unsolved issues (lack of populati on basis etc), there have not been any valid incidence studies on SCI. (17) As shown above, the actual SCI incidence in USA is included between 25 to 59 new cases per million populati on per year (18)(19)(20)(21)(22), with an average of 40, being almost 12,400 new cases in 2010. (23) The overall assumpti on of SCI incidence in USA on the next decades is that this will be in conti nuous ascension from 13600 in 2020 to 17560 in 2050 (23) as it can be seen in Fig. 1.
The incidence of SCI is smaller on other conti nents than North America, because of the lower presence of some main possible related causes: violence, motor crashes, very long speed ways and/or respecti vely bett er driving practi ces/rules, but also greater mortality on impact etc. (9)

CURRENT SCI EPIDEMIOLOGICAL DATA IN EUROPE, ROMANIA
The total populati on of the European Union (EU) is now about 500 million people (26) and an important number of people are suff ering after SCI in the related countries: around 330.000 individuals with 11.000 new SCI cases yearly. In Europe the average incidence calculated from 40 countries is 25 per million inhabitants yearly. (27) Herein below, there is emphasized the estimati on of the WHO regarding the TSCI incidence by large geographic regions (Fig. 3).   . Graphical representati on of the TSCI incidence esti mated median by WHO region -synthesis based on data from (27) In Romania, in 2008 there were 419 new cases of SCI pati ents with an incidence of 0.0190‰ (10) the informati on being collected from the Nati onal Database of Inpati ents. In 2009 it is menti oned in the same fi les a number of 407 such new cases (incidence of 0.0185‰ (28)the lowering value of incidence could be explained by the economic crisis and so, a decreased on motor vehicles sales). According to a current approach, in Romania there are 15,000 SCI people with an average age of 41.4 years. (10) These fi ndings of ours support an above exposed asserti on concerning the connecti on between (especially) the incidence of (poly) traumati c events -including of SCI type -and the economic consequent burden, but also the pre-traumati c occurrences one. All these data have been already published by us elsewhere. (29)

INCIDENCE BY AGE AND GENDER
The SCI pati ents are largely more frequent men, with an incidence of three to four ti mes higher than women. (8) Beginning with the 2000s, (9) the incidence rate in men decreased slowly: from 80.9% in seventi es to 77.1% nowadays (8,9) a possible explanati on of this lowering percentage in men, (15) may be the growing of women proporti on in driving vehicles/ thus parti cipati ng to traffi c at a greater extent.
The SCI incidence by age at injury have two peaks one at late teens and young persons and the other one aft er 60 year's old (18,21,30

INCIDENCE BY CAUSE
It is well known that being careful at work and at play and using all the safety driving rules, can protect for a possible SCI, but the specifi c preventi ng strategy can be sti ll improved by having an accuracy in the aeti ology of injury, too. (8,32) The more frequently met causes that can determine a TSCI are: motor crashes -the most common in USA 41% to 45% (31) and Canada (24,33), violence acts/ assaults, falls -that are the leading cause of SCI in elderly (8,32), sports accidents, work-related incidents, natural disasters etc.
To be menti oned that, regarding violencemainly gunshot -its share during the last three decades followed a sinuous trend: from 13.3% prior and in the fi rst third of this period, to almost ¼ (24.8%) of SCI in the 1990's and then back down to15%, since the second half of the last decade. (16)

CONCERNING THE OCCUPATIONAL MATTER
57.3% of such pati ents were employed at the ti me of their SCI; this proporti on appears severely decreased (11.6%) at one year aft er the injury, but enhances, in average, more than three ti mes (35.2% -tetraplegics, with 10% less than paraplegics); yet, almost half of the post SCI persons sti ll never succeeded to come back to work and it keeps like this, for the following 30 years. (16)

PREVALENCE
Prevalence is esti mated, in 2010, in the USA, between 232,000 and 316,000 (approximately 265,000) persons with SCI (higher than around fi ve years previously: 755). (11) Tetraplegia is met in 55.8% (most of them incomplete -39.5%, vs. only 16.3% complete -incomplete tetraplegia being the most frequent such neurologic/ dysfuncti onal category) and 42.8% have paraplegia (21.7% incomplete and 21.1% complete; the favorable trend: increase of incomplete to the detriment of complete -especially for tetraplegia -is found in the last 1 1/2 decade; yet, less than 1% of post SCI individuals succeed to become AIS E at discharge. (34) In Canada, there is the biggest number of cases of traumati c TSCI per million in a given year esti mati ng the higher prevalence of SCI as 1,298 per million. (32) In Sweden the TSCI prevalence was esti mated to be 227 and in Finland, 280 individuals. (32) In India, the TSCI prevalence was reported to be 236 (35) and in Australia 681 (36). Current surveys showed 112 cases in Chile (37) and between 35.1-41.9 in Norway. (30) As SCI frequently occur in (poly)traumati c situati ons, about half of all cases have, at least initi ally, other lesions, too. (38, 39) The mortality: (crude) death rate following SCI is big enough -mainly in the fi rst year(s)being signifi cantly higher (for instance, in the fi rst 12 years aft er SCI this is more than ten folds -9.3% (40) the general one -8.8‰ (41), parti cularly for those severely injured (16). The most current and common causes of death in SCI populati on are: septi caemia, pulmonary emboli, pneumonia. (40) The renal failure rate of death decreased in the last four-fi ve decades because of the neurogenic bladder advanced management. (16) Over the last about 3-4 decades, there has been a decline at almost the half (40%) in mortality during the fi rst 2 years aft er injury. But, aft er this initi al -considered criti cal -period, the decrease in mortality, seen on long-term, wasn't signifi cant anymore. (42). Over ti me (after the fi rst two years following SCI (42) mainly nowadays, it is considered that life expectancy in post SCI survivals is overall, slightly lower than in non-injured individuals. (16) Average length of initi al -in acute -hospitalizati on decreased to half (from 24 days, unti l 1979, to 12, since 2005) in the last about four decades and that of post acute/rehabilitati on period, to less than half -from 98 to 37 days (16); this is probably, but not exclusively, due to both, the growing proporti on of incomplete TSCI -certainly including with the contributi on of some essenti al primary preventi on of technical and regulatory kinds, such as for instance: improved security faciliti es in cars to be equipped with (airbags) and mandatory wearing for bikers/motor bikers -and improvement of integrated, comprehensive approaches, including in such conditi ons, within contemporary general medical advancements.
Average durati on of hospitalizati on , as well as number of re-admissions/year (events seen in 1/3 to 1/2 of all post SCI individuals) are longer, respecti vely, more frequent, in complete than in incomplete pati ents. (16,38) The related direct costs/economic burden for post SCI people, their families and society, and the indirect ones -that were esti mated to $66,626 per year in December 2010 (38) -are signifi cantly diff ering by injury's level and severity and based on its long-term associated pathology, respecti vely by level of qualifi cati on, pre-injury employment profi le and -again -severity of injury). (16,43 ) One must noti ce the constant augmentati on (about twice) of the average expenses per year and the esti mated lifeti me costs between 2004 and 2010 (without a spectacular improvement of the survival durati on).
We present below in Fig. 4, a short questi onnaire fi lled in, with some informati on about the SCI heath system, in the Teaching Emergency Hospital "Bagdasar-Arseni", The Nati onal Centre of Neuro-Rehabilitati on and also The Nati onal Reference Centre in Spinal Neurosurgery, in Bucharest, Romania. This questi onnaire has been designed for a complex research aimed to understand and show the burden of care (individual vs. public) of SCI management, in 30 developed countries all over the world and sent to us by Prof. S. Aito, former Vice-President of the Internati onal Spinal Cord Society (ISCoS).
To be pointed out that Romania is a unitary state and therefore, the regulati ons, including with the sanitary legislati on, are applicable throughout our country. Accordingly, we consider data resulti ng from the acti vity of the most important medical unit in Romania that approaches severe neuro-trauma, including with SCI, might have some relevance, yet without expecti ng our answers could represent the related situati on at the nati onal level. Additi onally, Prof. G Onose and some dedicated colleagues has contributed, around several months ago, to a large scale nati onal campaign, organized by the Romanian Associati on for Work Safety and Health -with the support of a big media/broadcast company -for preventi on of road traffi c accidents: they have provided informati on regarding the devastati ng medical and social consequences of the possibly severe polytrauma, including with neurotrauma, following such kind of accidents. Accordingly, they have consistently contributed to the making of a short educati onal for related preventi on, movie. To be specifi ed the dimension of such an overall current educati onal endeavour: this is embedded within a systemati cally conceived nati onal specifi c preventi on campaign -to be deployed, ti ll the end of this year, in six of the biggest towns of Romania, including with the Capital.

CONCLUSIONS
This arti cle used signifi cant epidemiological data in order to fulfi l an integrati ve view on SCI incidence and prevalence.
Even if TSCI incidence and prevalence has been enhanced in several countries (especially the developed ones) worldwide, there are no major changes in the last three decades (10) and additi onal related studies must be undertaken including in purpose to improve the preventi on prioriti es and acti ons. (27,32) Important eff orts should be done to prevent TSCI in both: young adult males and the ones caused by motor vehicle crushes and in older persons (focused on falls), respecti vely.
The results of this work showed that there are diff erences among geographic regions both in TSCI incidence and prevalence but the need for further research, especially in poor regions, may be overwhelmed by the fi nancial costs and resource requirements for specifi c data acquisiti on systems. (27) Also, a bett er strategy to avoid discrepancies in incidence and prevalence among some geographic region is needed, in order to diminish the global gravity of this devastati ng conditi on. (32)