Screening of chronic solvent encephalopathy : effectiveness, costs and work ability

Abstract

The global burden of occupational diseases (ODs) is heavy, and a notable part of work-related ill health remains unrecognised. The methods of reporting ODs and of conducting workers’ health surveillance around the world vary, and many parts of the world, have no surveillance or reporting at all.

In Finland, health examinations are mandatory if workers are exposed to hazardous substances or factors. Occupational health (OH) conducts nearly 200 000 exposure-based health-examinations every year which requires a great deal of resources. However, little has their effectiveness studied before.

The goal of the research was to study exposure-based occupational health examinations using one OD, chronic solvent encephalopathy (CSE) as a proxy. We assessed their effectiveness and costs, limitations to detect ODs, and solvent-exposed workers work ability.

Organic solvents present a ubiquitous occupational exposure, and in Finland, 20 000 workers are regularly exposed to them, and are thus obliged to attend exposure-based health examinations. Long-term solvent exposure may cause permanent central nervous system disturbances, i.e. CSE, which is characterised by cognitive memory and concentration problems. In Finland, five to seven CSE cases are diagnosed annually, and most common occupations among which they are found are painting, printing, floor-layering, metal degreasing, and boat building.

A questionnaire inquiring about exposure, CSE-compatible symptoms and health was sent to 3 600 workers. Symptomatic respondents were invited to OD physician’s clinical examinations. As a result, 18 new occupational CSE cases were diagnosed.

The study showed that new CSE cases can still be detected in Finland and that CSE is under-detected despite the mandatory OHS health examination system. The economic evaluation revealed that the SPC screening identified a new CSE case at 1/30 of the cost of the OHS health examinations. In addition, the CSE cases detected were younger and their retirement rate was lower than that of those detected by OHS (6.7% vs. 74%), which indicates that SPC screening was able to detect milder cases or those at an earlier phase, preserving work ability. However, the study showed that solvent exposure is an independent risk factor of poor work ability in elderly workers; it is comparable to a high level of alcohol consumption.

We retrospectively studied the OHS patient records of the 18 CSE cases detected through SPC screening. The study revealed that although mandatory the exposure-based OHS health examinations were conducted, they did not always follow the guidelines. Common health counselling seems to overrule exposure-based issues in health examinations.

This study was conducted in an industrialised country with a unique mandatory OHS system, good occupational hygiene, and declining solvent exposure levels. However, other countries and exposures probably also face the same kinds of challenges in OD detection. The global burden of occupational diseases (ODs) is heavy, and a notable part of work-related ill health remains unrecognised. The methods of reporting ODs and of conducting workers’ health surveillance around the world vary, and many parts of the world, have no surveillance or reporting at all.

In Finland, health examinations are mandatory if workers are exposed to hazardous substances or factors. Occupational health (OH) conducts nearly 200 000 exposure-based health-examinations every year which requires a great deal of resources. However, little has their effectiveness studied before.

The goal of the research was to study exposure-based occupational health examinations using one OD, chronic solvent encephalopathy (CSE) as a proxy. We assessed their effectiveness and costs, limitations to detect ODs, and solvent-exposed workers work ability.

Organic solvents present a ubiquitous occupational exposure, and in Finland, 20 000 workers are regularly exposed to them, and are thus obliged to attend exposure-based health examinations. Long-term solvent exposure may cause permanent central nervous system disturbances, i.e. CSE, which is characterised by cognitive memory and concentration problems. In Finland, five to seven CSE cases are diagnosed annually, and most common occupations among which they are found are painting, printing, floor-layering, metal degreasing, and boat building.

A questionnaire inquiring about exposure, CSE-compatible symptoms and health was sent to 3 600 workers. Symptomatic respondents were invited to OD physician’s clinical examinations. As a result, 18 new occupational CSE cases were diagnosed.

The study showed that new CSE cases can still be detected in Finland and that CSE is under-detected despite the mandatory OHS health examination system. The economic evaluation revealed that the SPC screening identified a new CSE case at 1/30 of the cost of the OHS health examinations. In addition, the CSE cases detected were younger and their retirement rate was lower than that of those detected by OHS (6.7% vs. 74%), which indicates that SPC screening was able to detect milder cases or those at an earlier phase, preserving work ability. However, the study showed that solvent exposure is an independent risk factor of poor work ability in elderly workers; it is comparable to a high level of alcohol consumption.

We retrospectively studied the OHS patient records of the 18 CSE cases detected through SPC screening. The study revealed that although mandatory the exposure-based OHS health examinations were conducted, they did not always follow the guidelines. Common health counselling seems to overrule exposure-based issues in health examinations.

This study was conducted in an industrialised country with a unique mandatory OHS system, good occupational hygiene, and declining solvent exposure levels. However, other countries and exposures probably also face the same kinds of challenges in OD detection.

AMMATTITAUTI EI LÖYDY AAMIAISESTA JUTTELEMALLA

Tth el Heidi Furun väitöskirja paljasti, että työterveyshuollon terveystarkastuksissa keskitytään enemmän elämäntapaneuvontaan kuin työhön ja ammattitauteihin, joita jää siksi tunnistamatta. Perinteiset terveystarkastukset osoittautuivat kustannustehokuudeltaankin varsin vaatimattomiksi.

Työn vaaratekijöiden vuoksi tehtäviä pakollisia terveystarkastuksia tehdään Suomessa melkein 200000 vuodessa, mikä vaatii huomattavia resursseja. Niiden toimivuutta ja kustannustehokkuutta ei kuitenkaan ole tutkittu. Tiedetään myös, että ammattitaudit ovat alidiagnosoituja koko maailmassa, eikä Suomi ole poikkeus.

Väitöskirjassa perehdyttiin työterveyshuollon lakisääteisten terveystarkastusten toimivuuteen ja kustannustehokkuuteen käyttämällä esimerkkinä yhtä ammattitautia, liuotinaivosairautta. Se on muistivaikeuksina ilmenevä pysyvä aivovaurio, jonka pitkäaikainen liuottimien käyttö aiheuttaa. Suomessa löytyy vuosittain 5-7 tapausta, joista lähes kaikki päätyvät tapaturmaeläkkeelle. Tyyppiammatteja ovat maalarit, painajat, veneenrakentajat ja asentajat.

Työterveyslaitoksella toteutettu tutkimus alkoi kyselyllä 3600 liuottimia käyttävälle työntekijälle Uudellamaalla ja Pohjanmaalla, ja oireiset kutsuttiin lääkärin tutkimuksiin. Sitten verrattiin tutkimusseulonnan ja terveystarkastusten kustannuksia, tarkasteltiin liuotinaltistuneiden työkykyä sekä selvitettiin potilaskertomuksista terveystarkastusten toteutumista.

AMMATTITAUTEJA LÖYTYI ENEMMÄN JA EDULLISEMMIN Tutkimus osoitti, että liuotinaivosairaus on alidiagnosoitu huolimatta pakollisista terveystarkastuksista. Tapauksia löydettiin 18 eli huomattavasti enemmän, kun vuodessa koko maasta. Ne havaittiin varhaisemmassa vaiheessa, lievempinä, kun työkyky ei ollut vielä mennyt. Ikääntyvillä työntekijöillä liuottimet paljastuivat kuitenkin huonon työkyvyn riskitekijäksi. Kyselyllä alkava seulonta osoittautui myös erittäin kustannustehokkaaksi: kustannukset yhtä löydettyä ammattitautia kohden olivat vain 1/30 terveystarkastuksiin verrattuna.

ELÄMÄNTAPANEUVONTA JYRÄÄ TYÖHÖN LIITTYVÄT ASIAT Vanhat potilasasiakirjat paljastivat, että terveystarkastuksissa ei oltu aina noudatettu ohjeistuksia lakisääteisten altistelähtöisten tarkastusten sisällöstä. Niissä oli keskitytty elämäntapaohjaukseen työhön liittyvien asioiden kustannuksella, ja siksi ammattitautitapaukset eivät löytyneet.