Scientific impact, sick-leave cost and legal repercussion Lower Back disorders and their labour relation in Spain Safety

The source of lower back disorders, especially intervertebral disk displacements, is a burning issue in today’s scientific community, largely because they are so hard to pin down as the complex effect of many different causes, including genetic, degenerative, biochemical, medical, mechanical, traumatic and psychosocial factors.

Until the end of the twentieth century it was thought that low back pain stemmed mainly from muscle strain or organic alterations such as arthrosis, scoliosis or intervertebral disk displacement, but research in the last twenty years has shown that most organic alterations of the spinal column are irrelevant and bear no relation to back pain. In 80-85% of the cases of low back pain the final diagnosis is established as a non-specific pathology due to the lack of any relation between the results of complementary explorations and the patient’s medical record.

These acute episodes of non-specific lower back pain are often triggered by improper use of the supporting musculature, causing persistent activation of the nerve fibres; this in turn triggers and maintains the pain, muscular contracture and inflammation.

In subacute cases, even when the initial cause is solved, the pain, inflammation and contracture may linger on due to persistent changes in the spinal neurones.

Finally, in chronic cases, the nerve alterations are exacerbated by muscular and psychosocial factors, sparking off a vicious circle that hinders the spontaneous recovery of the affected person. Physical inactivity generates loss of muscular power and coordination and, in the mid term, atrophy and the concomitant worsening of the initial clinical picture. The persistence of the pain initially leads to reactions of fear and avoidance in the sufferer; in the longer term a pervasive feeling of uselessness and self-pity may take over, with the responsibility for the pain being thrown onto third parties.

Lower back pain occupational risk factors are considered to be: traumas, load handling, bending and twisting, vibration, strained postures, driving, repetitive movements, smoking, obesity, seating position, muscle weakness and depression.

In the occupational-preventive field it is the occupational factors associated with back pain that are of most interest to us, mainly the mechanical factors such as heavy work, static working postures, frequent twists and turns of the trunk, brusque movements and hoists, repetitive work and vibrations, among others. When the psychosocial factors kick in they sometimes become even more important than the initial mechanical factors, lengthening the disorder and calling for greater and more prolonged attention and economic benefits (temporary incapacity, etc.)

There is now a need for assessing the main epidemiological factors related to low back pain: age, gender, strength and flexibility of the back musculature together with geographical aspects such as the sufferer’s country of residence.

Lower back disorders have a very high cost in terms of sick leave, loss of working days and occupational limitations; this article therefore makes an attempt to calculate this cost to the health system and society as a whole.

This group of disorders is also particularly conflictive and controversial, often straying from the occupational and preventive field into the legal arena, thus inflating even more their personal and social cost.

Development

The importance and prevalence of low back pain or lumbago cannot be overestimated. Witness the fact that 80% of the population are thought likely to suffer from this disorder at some moment in their lives (EPISER, 2001 study). Some studies have tried to establish gender-related differences, coming up with contradictory results: some find the disorders to be commoner in men, others in women and others find no significant gender-based aetiology at all.

Lumbar intervertebral disk displacement is one of the main causes of lower back pain; it can crop up at any time of life but is commonest between the fourth and fifth decade with a 3:1 men-to-women ratio. The most frequent location is L4-L5 and L5-S1. It is estimated that about 4 to 6% of the population will have a symptomatic intervertebral disk displacement though magnetic resonance imaging shows up asymptomatic intervertebral disk displacement in 21% of 20-59 year-olds and 36% of people aged 60 and over, without necessarily being accompanied by discernible symptoms.

In the working world the main lumbago risk factors are considered to be direct occupational traumas, manual load handling, jobs calling for a lot of bending and twisting, whole body vibration, strained postures, prolonged vehicle driving, repetitive movements, smoking (probably due to coughing rather than any toxic effect of the tobacco), obesity, seating positions, weak muscular development, depression and other mood upsets.

Risk factors of lumbago-caused prolonged sick leave are considered to be: treating acute episodes with bed rest, poorly chosen surgical procedures, low economic and cultural level, lack of job satisfaction, the length of the sickleave itself, psychological upsets (personality disorders, depression, anxiety, alcoholism, drug abuse) and obesity.

Ascertaining the cost of these disorders is tricky. It is said that 90-95% of lumbagos are cured in 1-2 months; the remaining 5-10%, becoming chronic, account for 85-90% of the total cost caused by this disorder. The most alarming aspect is that these figures, far from falling, are in fact increasing [1], and not only in Spain but also in other comparable countries. Recent figures from Germany speak of a direct chronic-low-back-pain burden in this country of about €7000 per person, while absenteeism accounted for 75% of the total per-patient cost of low back pain in Germany^[2].

How are these disorders reflected in the current medical literature?

It is difficult to establish with any accuracy the current state of medical research into this matter and the publication thereof. To simplify the task, the normally recourse is to make bibliographical searches using the Pub-Med Central medical database⁽¹⁾.

Whenever there is a need in medicine for a bibliographical search into a specific matter the normal tactic is to call up key words contained in the publications concerned, either singly or in association with other words and concepts. This search is supported by means of health science descriptors (DEsC)² (2), which are words or expressions of the language used by the thesaurus constructor to designate the representative concepts of the document and the questions used by the indexer.

Lower back disorders and work

In the case in hand, i.e., the concept of occupational damage (especially work accidents and occupational disease) and its application in practice to low back pain (lumbago, discopathies and the like), Desc offers us many options. The commonest hits are low back pain (19,607 publications), intervertebral disk displacement (14,322 publications), ahead of other less common terms such as intervertebral disk degeneration, sciatica, neuropathy, radiculopathy, back pain and spinal nerve roots. We will limit ourselves to the first two as the most representative of these disorders.

Se consideran factores de riesgo de incapacidad laboral por dolor lumbar y baja prolongada: reposo en cama, terapias quirúrgicas inadecuadas, nivel económico-cultural, insatisfacción laboral, trastornos psicológicos, abuso de fármacos y obesidad

Table 1 shows the number of Pub-Med publications featuring each of these concepts and also their first and last year of appearance. The highest number of hits is associated with the general term of back pain or those specifically related to radicular pain. The first Pub-Med publication referring to this matter dates from 1812, specifically in relation to sciatica. All the rest date from the twentieth century, some from the start of the century, such as those referring to spinal nerve roots in 1908. The ongoing interest and importance of the search terms is shown by the fact that the latest hits date from 2011, the search year itself.

Search made on 1 May 2011. Source: http://www.ncbi.nlm.nih.gov/pubmed. Ref: Mª T Vicente-Herrero et al. Grupo de Investigación en Medicina del Trabajo (GIMT).

It we now wish to bring the labour relationship into the picture, weighing this against the number of publications that associate lumbago to clinical-healthcare aspects, we then have to associate descriptors to the concept of low back pain. The results of this search cannot just be tagged onto the rest. It should be borne in mind here that there might be double or even triple overlap, since the publications comprise several key words or descriptors, selected by the author(s) to facilitate their subsequent search as reference by interested parties. In many cases several of these selected key words will coincide in the same publication; this will introduce a bias into the search.

Our objective here is to find out how far aspects related to the occupational medicine doctor’s work are referenced and reflected in publications in relation to this matter, either singly or, more commonly, in association with other clinical or occupational concepts. The same publication may therefore be included in several of the groups. The results of this selective search are shown in Table 2.

Pub-Med search terms	Number of medical publications	Years of publication
Lumbago- Socio-occupational aspects
Low back pain AND Occupational cost	219	first in 1962 and last in 2011
Low back pain AND Occupational risk factors	722	first in 1976 and last in 2011
Low back pain AND Occupational medicine	507	first in 1962 and last in 2011
Low back pain AND Occupational health	1284	first in 1951 and last in 2011
Low back pain AND Social medicine	232	first in 1979 and last in 2011
Low back pain AND Absenteeism	288	first in 1965 and last in 2011
Low back pain AND Handicap	47	first in 1981 and last in 2011
Low back pain AND Disability	3265	first in 1951 and last in 2011
Low back pain AND Impairment	423	first in 1975 and last in 2011
Low back pain AND Incapacity	35	first in 1983 and last in 2010

Search made on 1 May 2011. Source: http://www.ncbi.nlm.nih.gov/pubmed. Ref: Mª T Vicente-Herrero et al. Grupo de Investigación en Medicina del Trabajo (GIMT).

An analysis of the results shows the vast amount of information published on the general concept of low back pain (19,607 publications), which began at the start of last century (1925). Also prominent are the publications based on diagnosis (12,583 publications) or therapy (12,133 publications). Fewer publications are flagged up when risk factors are studied (1837 publications) and the aspects bound up with the prevention and control of these disorders (1314 publications), subjects that for obvious reasons are of special interest to the occupational medicine doctor and occupational health as a whole. All the publications are still fully relevant today, the last dating from 2011.

Search made on 1 May 2011. Source: http://www.ncbi.nlm.nih.gov/pubmed. Ref: Mª T Vicente-Herrero et al. Grupo de Investigación en Medicina del Trabajo (GIMT).

Risk factors of lumbago-caused prolonged sick leave are considered to be: bed rest, poorly chosen surgical procedures, low economic and cultural level, lack of job satisfaction, psychological upsets, drug abuse and obesity

A specific check of those publications containing among their key words terms linked to the specific activity of the occupational medicine doctor and occupational health shows a higher number of publications (1284) with this second term – occupational health – since it is more generic and probably more familiar and more often dealt with by healthcare professionals outside our ambit. That said, the most numerous group of publications in this sense refers to the concept of disability associated with low back pain (3265 publications), albeit much lower than the previous results with aspects linked only clinically to the disorder.

This group of publications is also seen to be later in time (the first ones appear in 1951), although their present-day relevance is shown by the fact that the most recent date from 2011.

The results of the low-back-pain bibliographic search are particularly striking with a huge number of hits (19,607 publications). The first references date back to last century (1925)

A striking fact is that only 507 publications have studied the occupational risk factors, bearing in mind the heavy influence that work may bear on the appearance and subsequent development of these disorders and the preventive work needed from both companies and occupational medicine doctors.

Similarly, the results for the intervertebral disk displacement-based search are shown in Table 3. There are many hits with the generic term of intervertebral disk displacement (14,322) and they likewise date back a long way, right back to 1947. As in the previous case it is striking how many of the publications flag diagnosis as a key word (10,027 publications) or therapy (9169), with far fewer publications flagging risk factors (439); they are also much later in terms of the earliest appearance (1975).

As for references to intervertebral disk displacements in association with the occupational medicine activity, as shown in the table, the number of publications is pretty low, topping one hundred only in association with disability (685 publications) and the resulting impairment (109 publications). Only 59 publications make reference to the occupational risk factors as situations to take into account in the prevention and subsequent evolution of these processes.

Worthy of note here, however, is the fact that it was not until well into the twentieth century that the first publications on this disorder appeared in Pub-Med. Not until 1947, in fact, did the first publication on intervertebral disk displacement as a general concept appear and not until 1958 was this health problem first brought into relation with occupational health.

The possible occupational cost of intervertebral disk displacements is reflected in only 20 publications, the most recent dating from 2008; 25 publications bring intervertebral disk displacement into relationship with absenteeism, the last dating from 2010.

Can the economic-occupational cost of lower back disorders in Spain be calculated?

A check of publications associating low back pain with the specific activity of the occupational medicine doctor, on the one hand, and, on the other, with occupational health shows a predominance of the latter (1284 publications) probably because it is a more familiar and more often dealt-with subject

As we have already seen when checking the prevalence figures, nearly all individuals will suffer an episode of low back pain at some time in their lives (between 65 and 90%). Each year about 5-25% of the general population will suffer low back pain, but this percentage rises to 50% in working age (18-65 age bracket)[3]. Both sexes suffer equally from low back pain but there is an age difference, with a peak in the 25 to 45 age bracket, i.e., within the range of the working population^[4].

In developed countries low back pain is the biggest cause of occupational incapacity in under 45s and the third biggest in over 45s, outnumbered only by ischaemic heart disease and other rheumatic processes^[5].

The same goes for Spain: in 2010 lower back disorders were the main cause of sick-leave, accounting in all for 73.4% of the total (Figure 1).

Coming up with any precise calculation of the economic cost of lower back disorders, in terms of working days lost through temporary incapacity, is a very difficult and error-strewn task. Bringing all the disparate cases under a single cost umbrella in itself introduces a bias into the equation. The situation is also muddied by the different social-security schemes and payment systems of the workers concerned and the fact that the first 15 days of temporary incapacity are paid by the firm rather than the social security authority.

Nonetheless, it is still worthwhile calculating a possible minimum cost as a ballpark figure, to give us some idea of the cost of this problem to the state in terms of temporary incapacity as an indirect cost, not to mention the direct costs of the healthcare expense in doctors’ surgeries, drugs, complementary tests, etc.

The calculation to be made below tries to boil it down to a minimum number of processes and resulting days off, calculating these days of temporary incapacity on the basis of an approximate economic cost per working day. This has been calculated threefold in terms of bottom-line figures established for 2010. These three methods are the following in order of increasing cost:

• IPREM (a means-testing index) (cost per day = €17.55).
• SMI (minimum interprofessional wage) (cost per day) = €21.11).
• Calculation from the figures of the cost per day of working days lost of the Spanish Social Security Institute (INSS) for 2010 (€31.35).

Quantifying the cost of low back pain (lumbago) is especially important since it figures among the 12 most frequent diagnoses associated with lower back disorders and among the 30 most frequent in the general calculation of temporary incapacity in Spain (taking in about 60% of all the processes causing temporary incapacity in Spain) during 2010.

The percentage figures are shown in Table 4.

Ref: Mª T Vicente-Herrero et al. Grupo de Investigación en Medicina del Trabajo (GIMT).

The occupational cost of intervertebral disk displacements is dealt with in only 20 publications, the most recent in 2008, while occupational absenteeism features in 25 publications, the latest in 2010

A check of all the diagnoses by ICD code shows that the most frequently quoted lower back disorder in sick-leave notes is low back pain or lumbago (Code 724.2), accounting for 67.48% of all diagnoses, followed by sciatica (Code 724.3), representing 24.81% of the total. Both diagnoses, taken together, add up to 92.61% of the total of lower back disorders under consideration.

Working from the standard temporary-incapacity times shown in the manual published by INSS in 2009[6], a theoretical calculation of the working days lost in Spain in 2010 due to these lower back disorders comes out as 2,613,202 days. Nonetheless, the days actually lost were 6,188,626, i.e., the actual temporary-incapacity downtime exceeded the theoretical calculation by 3,575,424. Table 5.

Ref: Mª T Vicente-Herrero et al. Grupo de Investigación en Medicina del Trabajo (GIMT).

Table 6 shows the results for lower back disorders, lumping together all the ICD codes included among the 30 most frequent diagnoses.

Ref: Mª T Vicente-Herrero et al. Grupo de Investigación en Medicina del Trabajo (GIMT).

Back-related illnesses accounted for 9.01% of the total number of episodes involving temporary incapacity in Spain during 2010 and 9.76% of the total working days lost.

On the basis of this figure of 9.76% of days lost, an estimate can be made of the economic cost of the whole set of lower back disorders: i.e., 9.76% of the total temporary incapacity expenditure for all episodes in Spain during 2010.

The 2010 expenditure in temporary incapacity benefit was about 2.577 billion euros (including direct payment by the Social Security authority and delegated payment of the benefit through the employer), with about 82,200,000 temporary-incapacity days paid in all, leading to a average temporary-incapacity cost per day of €31.35, always allowing for the inherent bias arising from the non-consideration of differences in contribution arrangements and considering only the cost corresponding to the INSS. Sick-leave days paid by the employer are therefore not included in this estimate (the first 15 days of each episode); it also excludes any workers whose contingencies might be covered by mutual insurance companies instead of the INSS.

9.76% of €2,577,048,410 (Spain’s total temporary incapacity expenditure in 2010) comes out as €251,519.9248. This is a ballpark figure but it does give us some idea of the real temporary-incapacity cost of this group of diseases.

As we have already seen the standard duration times for these diseases, as laid down in the INSS’s Manual of Standard Times for Temporary Incapacity, are greatly exceeded in practice. If these standard times were in fact fulfilled, this would save about 145,305,231.4 working days, with a cost saving of €112,089,542.4.

In detailed form the three different bottom-line calculations, in increasing order of cost per working day, come out as follows:

• Cost of lower back disorders involving temporary incapacity based on the bottom-line figures of IPREM 2010 (with a cost per day of €17.55) = €62,748,691.20; this would represent 2.4355% of Spain’s total temporary-incapacity expenditure in 2010 (assuming the bias of a calculation based on a cost per day of €31.35).
• Cost of lower back disorders involving temporary incapacity based on the bottom-line figures of SMI 2010 (with a cost per day of €21.11) = €75,477,200.64,; this would represent 2.929% of Spain’s total temporary-incapacity expenditure in 2010 (assuming the bias of a calculation based on a cost per day of €31.35).
• If we bear in mind the cost per day of €31.35, which served as the basis for obtaining Spain’s overall temporary incapacity expenditure in 2010, the total figure would come out as €112,089,542.4, representing 4.35% of Spain’s total temporary incapacity expenditure for all processes.

The minimum adjusted cost according to the three cost-per-day methods used for lower back disorders in Spain would be somewhere in the range of €62,748,691.20 to €112,089,542.4.

Is there an additional legal repercussion?

Medicine and Law are two disciplines that, far from being independent, are increasingly intermeshed, sharing common and complementary traits. There are therefore many professional situations in which both doctrines are inextricably involved, and the inputs of both have to taken into account to gain any realistic picture of the whole situation. If this is so in general terms, it is even truer in a speciality like occupational medicine, the only medical speciality that is governed and regulated by law.

Intervertebral disk displacements as work accidents feature in 5526 judgments, 94.34% corresponding to labour law. Low back pain as a work accident features in 5472 judgments, 95.67% corresponding to labour law. Both disorders taken together as work accidents feature in 1619 judgments, 96.97% corresponding to labour law

These illnesses are sometimes chronic, developing over a long period of time. This often leads to complex situations of difficult resolution. If they are not dealt with properly in the administrative sphere they might easily spill over into the legal or judicial arena.

People in general, and in our particular case here workers suffering from lower back disorder, are entitled in the first instance to submit an administrative claim if they conceive a situation as unfair or unresolved. If this claim is ignored or unsatisfactorily dealt with they can then lodge an appeal. If this is turned down they can then take legal action.

The problems posed by chronic illnesses in general, and ipso facto those of the lower back, crop up when the pain leads to situations of work incompatibility or partial or total limitations for carrying it out. These downtime situations might be temporary or permanent. Moot points here are aptitude, in any of its various meanings, and adaptation of the person’s working conditions in the case of specific risks that affect that person particularly due to his or her illness.

The adjusted minimum cost for lost working days due to lower back disorders in Spain in 2010 comes out somewhere in the range of €62,748,691.20 to €112,089,542.4

When this situation cannot be dealt with properly within the firm or by means of current administrative procedures the next step would be legal action.

To find out the current situation of lower back disorders within the legal sphere, we can make a search in the channels that facilitate this option; in this case legal portals.

A legal portal is essentially a gateway to all sorts of legal aspects: a legal document database, a legal resource search engine, a website directory, a free website hosting service, an e-magazine of IT law, free access to the contents of the Official State Journal(BOE in Spanish initials) plus other added services.

The object of this legal trawl is to investigate the case-law relationship of work accidents to low back pain and intervertebral disk displacements. A separate check is made for each aspect and then the two together, since many of the judgments dealing with this problem might include both in the same ruling.

According to this database check, intervertebral disk displacements associated with the concept of work accident feature in 5526 judgments, 94.34% of them corresponding to labour law (5213 judgments), with very few being dealt with by civil, mercantile, penal or administrative procedures.

The figure is very similar for low back pain in relation to work accidents, with 5472 judgments linking both concepts, 95.67% of them corresponding to labour law; as in the previous case the other procedures account for little.

A trawl for both together, in association with the term work accident, shows 1619 judgments in which they feature simultaneously, again with the lion’s share corresponding to labour law (96.97% or 1570 judgements). The results are shown in Table 8 (Figures 2 ,3, and 4).

Search made on 9 May 2011. Source: http://www.westlaw.es/index_spa.html. Ref: Mª T. Vicente-Herrero et al. Grupo Investigación Medicina del Trabajo (GIMT).

As for the case-law trend over time (Table 9) (Figures 5 and 6), a check from 2000 to 2010 shows that all search items have remained fairly similar from 2001 to date, with slight ups and downs from 2005 to 2009. This trend seems to have held steady in 2011, according to the figures obtained in the first quarter of the year (January to April).

Ref: Mª T Vicente-Herrero et al. Grupo de Investigación en Medicina del Trabajo (GIMT).

Conclusion

This study has looked at the set of lower back disorders, especially low back pain, analysing their economic costs in terms of temporary incapacity and their legal repercussion. The conclusion we can draw from this study is that these disorders are widespread with knock-on effects throughout the whole society and the working world in particular. The economic costs are high, especially in terms of temporary incapacity expenditure; taken as a whole these disorders represented 2.5 to 3% of Spain’s temporary incapacity expenditure in 2010.

These situations are very difficult to cope with in the working world or by administrative procedures and often spill over into the courts. This adds the problem of legal costs to those already generated by temporary incapacity and the healthcare expenditure in Spain.

Improved procedures and deeper knowledge of these disorders, of their concomitant occupational risks and the administrative options open to sufferers, healthcare workers and companies, would be beneficial for not only the affected parties but for society as whole, ensuring a more efficient use of healthcare resources.

⁽¹⁾ PubMed Central es una base de datos gratuita de textos/publicaciones de literatura científica en Biomedicina y Ciencias de la Salud.

⁽²⁾ DEsC. Descriptores en Ciencias de la Salud fue creado para servir como un lenguaje único en la indización de artículos de revistas científicas, libros, anales de congresos, informes técnicos y otros tipos de materiales, así como para ser usado en la búsqueda y recuperación de asuntos de la literatura científica en las fuentes de información disponibles en la Biblioteca Virtual en Salud.

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PARA SABER MÁS

1. Borenstein DG. Epidemiology, etiology, diagnostic evaluation and treatment of low back pain. Curr Opinion Rheumatol 1999; 11: 151-157
2. Juniper M, Le TK, Mladsi D. The epidemiology, economic burden, and pharmacological treatment of chronic low back pain in France, GermanyBorenstein DG. Epidemiology, etiology, diagnostic evaluation and treatment of low back pain. Curr Opinion Rheumatol 1999; 11: 151-157
3. Patel AT, Ogle AA. Diagnosis and management of acute low back pain. Am Fam Physician 2000; 61: 1779-1786
4. Moyá Ferrer F. Lumbalgia. En: Alonso A, Álvaro-Gracia JM, Andreu JL, Blanch i Rubiò J, Collantes E, Cruz J, Gratacós J et al., editores. Manual SER de las enfermedades reumáticas. Madrid: Médica Panamericana, 2000.González Viejo MA, Condón Huerta MJ. Incapacidad por dolor lumbar en España. Med Clin (Barc) 2000; 114: 491-492.
5. Autoría múltiple. «Tiempos estándar de Incapacidad Temporal». Edita: Instituto Nacional de la Seguridad Social. NIPO: 791-09-078-8. Depósito Legal: M-28597- 2009. Autores. Álvarez-Blázquez, Fernández F, Director. Jardon Dato E, Carbajo Sotillo MD, Terradillos García MJ, Valero Muñoz MR, Robledo Muga F, Maqueda Blasco J, Cortés Barragán R, Veiga de Cabo J, coordinadores.

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