[Temporary disability: analysis strategies]

[Analysis of the length of sick leave in Andalusia. Associated factors]

OBJECTIVE

To analyse the length of sick leave (SL) and its associated factors in Andalusia.

DESIGN

Descriptive observational study.

SETTING

Andalusia.

PARTICIPANTS

A total of 1,633,405 sick leave forms issued from the 1st January 2002 to the 31st of December 2006 for any reason by Primary Health Care doctors in the Public Health Service, were analysed.

MAIN MEASUREMENTS

Descriptive and bivariate analysis of SL health complaints and their length according to gender, rural or urban environment, Social Security scheme, diagnosis and reason for discharge. A model of multiple lineal regression was completed.

RESULTS

The overall incidence of SL was 15.83 health complaints per 100 Social Security members per year (14.73 in males and 17.24 in women). The most frequent diagnoses for the SL were, lower back pain and the common cold. The mean length of the SL health complaint episodes in men was lower than that of women by 7 days. The majority of the SL health complaints were resolved in less than one month (71.7%). The SL complaints that lasted longer were: endocrine diseases and immune disorders, neoplasms and mental disorders. The mean length of SL is higher in the rural environment (45.4) compared to urban (36.9). The variables that predict the length of sick leave in the model were gender, age and address location.

CONCLUSIONS

Different factors to the diagnosis have a large influence on the length of SL. The main variables that affect this are, age, gender and a rural environment.

[Analysis of short-term time off of health workers in a health area]

OBJECTIVE

To describe the characteristics of short-term time off work (STT): duration, causes and distribution by age, and sex.

DESIGN

Descriptive, observational study.

SETTING

Area 1, Madrid, Spain.

PARTICIPANTS

Health workers with STT in Area 1, Madrid, during the first 6 months of 2003.

MAIN MEASUREMENTS

The variables studied were: date of start and finish of STT, its duration, its cause (ICD-9), age, and sex.

RESULTS

Four-hundred eighteen health workers (3.7%), with a mean age of 32.7+/-20 years old and 78.79% women. Respiratory pathology was the most frequent cause of STT (38%) in both sexes and in all age-groups, except in the youngest (<25), in whom bone and muscle pathology was more common. In decreasing order of frequency appeared bone and muscle pathology (26%), infections (13%), and mental illness (10%). The average duration of STT was 38.8+/-88.7 days. There was a statistically significant relationship between the duration of STT and its cause. Respiratory pathology was the shortest (8.85; 95% CI, 6.54-11.17) and mental illness, the longest (153.8; 95% CI, 87-220.75). The age group with most STT (37-45 years old) had a mean length of STT lower (26.93; 95% CI, 16.34-37.51) than the oldest age group (>56), which had less, but longer-lasting STT (57.18; 95% CI, 10.74-103.63), though this was not statistically significant.

CONCLUSIONS

The pathology causing STT is the factor that most determines STT's duration. Its prevention would be the best way of managing STT.

[Factors determining the duration of temporary disability and return to work in a health district of Galicia]

OBJECTIVE

To determine the factors associated with the incidence and duration of temporary work incapacity (TWI) in a health district.

DESIGN

Descriptive and retrospective study.

SETTING

South health district of the province of Lugo, Spain.

PARTICIPANTS

A random sample of 1513 cases was selected among the total of episodes of TWI, during 3 years period.

MAIN MEASURES

The main factors analyzed are, on the one hand, the socio-demographic characteristics of the patient, his or her social security (SS) scheme, diagnosis that justifies the TWD, and the prescription date; and, on the other hand, the age, sex, specialised training, time in the post and years in practice of the physician who prescribes the TWI. The comparison of the means was carried out using variance analysis and the Kruskal-Wallis test. The relative effect of each variable on the probability of returning to the work was estimated through Cox regression models.

RESULTS

The mean duration of the episodes of TWI was of 74+/-103 days. The most frequent diagnoses were those of the bones-muscles and joints (BMAJ), injuries and poisonings (IAP), and respiratory diseases (RD). The probability of returning to work is reduced with the increase of the age, with agrarian and autonomous SS affiliates, with diagnoses of mental disease or diagnoses of the circulatory system, and in cases prescribed by older doctors or less time in the post.

CONCLUSIONS

The mean duration of the episodes of TWD is higher than that of other Spanish studies. The most influential factors in the return to work are the age of the patient, the SS scheme and the diagnosed illness.

[Short-term time off work: its characteristics at a health centre from 2000-2002 inclusive]

OBJECTIVE

To describe short-term time off work procedures, its duration and the determining factors in an active population covered by health insurance at a health centre.

DESIGN

Descriptive and observational study of prevalence.

SETTING

Ribadeo Health Centre, Lugo, Spain.

PARTICIPANTS

All sickness certificates issued in 2000-2002 were included (n=1714).

MAIN MEASUREMENTS

The age and sex of each patient, amount of time off, place of residence (rural/urban), job (according to CNAE-93), type of social security cover, and cause of illness (according to CIE-9) were all recorded.

RESULTS

The short-term time off rate ran at 14.79 per 100 persons a year. Mean age was 40.13 (SD, 12.08); 936 (54.6%) were male. 85.7% of time-off periods were due to chronic illness, 12.2% to accidents not at work and 2.1% to accidents at work. Main associated pathologies were bone and muscular problems (25.7%), respiratory system problems (16.4%), and traumatisms (16.2%). All episodes accounted for the loss of 114,355 working days. Mean days lost per worker were 99.79 (SD, 136.37). Mean days lost per episode were 66.72 (SD, 98.79). Multivariate analysis showed that longer episodes were associated with older patients, women and the self-employed or workers at home. The longest periods off work were caused by cancer and mental disorders.

CONCLUSIONS

Age, sex, job, and pathology are variables related to short-term time off work.

Fatores relacionados ao absenteísmo por doença em profissionais de enfermagem

OBJETIVO: Analisar os afastamentos de curta duração de profissionais de enfermagem de um hospital universitário. MÉTODOS: A população estudada foi de 965 profissionais de enfermagem de um hospital universitário e que estavam em atividade em 1º de janeiro de 2000.Foram analisados afastamentos do trabalho desse grupo por até 30 dias em um ano civil. Foi feita a descrição dos afastamentos por doença (agregados em um ano), da demanda pelo serviço e dos diagnósticos. Por meio de análise multivariável foi estimado o risco relativo utilizando a distribuição de erro binomial negativa. RESULTADOS: Cerca de 65% dos trabalhadores geraram 1.988 consultas, das quais 68,6% resultaram em afastamento do trabalho. Os grupos com maior demanda foram técnicos de enfermagem, mulheres e estatutários (OR=1,61; 1,47; 1,53 respectivamente). Os diagnósticos mais freqüentes foram os relacionados ao aparelho respiratório. Para afastamentos, não foram encontradas diferenças para gênero e idade. Pelo menos um afastamento foi concedido a 57,6% da população, o que corresponde a 87,8% dos trabalhadores atendidos. Estes geraram um total de 1.364 afastamentos, 1,41 por trabalhador e 5.279 dias perdidos. A análise multivariável, ao considerar separadamente os sexos, mostrou efeito apenas do vínculo empregatício (RR=1,45 e RR=2,43) para mulheres e homens. CONCLUSÕES: Existe relação entre afastamento e vínculo empregatício. Faz-se necessário incluir outras variáveis, como tempo na empresa, turno e carga reprodutiva, em futuras pesquisas.

[Negative binomial distribution versus Poisson in the analysis of recurrent phenomena]

OBJECTIVE

The aim is to unfold the difficulties likely to arise in risk calculations through aggregated database when the studied phenomenon is recurrent and to display the negative binomial distribution as a valid and simple alternative to analyse this kind of phenomenon.

METHODS

When the studied phenomenon is recurrent, the analysis by means of the Poisson regression can provoke overdispersion or extra-poisson variance, what leads to underestimating the standard errors in coefficients and may divert into the statistical significance of factors which as a matter of fact are not associated with the phenomenon beforehand. The negative binomial can grasp part of the variance which the Poisson is unable to identify. In order to check this out, the fit of both distributions were compared, based on the number of hospitalizations of individuals aged between 65 and 69, during 1996. This comparison was carried out by means of two different aggregated databases: by individuals and by variables.

RESULTS

There were differences in the fitted models by means of both distributions in both databases. By the analysis of the residuals, when using the base by individuals, the negative binomial fits correctly 67.9% of the observations badly fitted by the Poisson. Using the aggregated variables database, the percentage is 50%. In both cases, Poisson estimates four out of the six studied variables as significant. As to the negative binomial, there are two significant based on individuals and one in the variable database.

CONCLUSION

The existence of overdispersion is frequent in recurrent-type phenomena. When this occurs, the negative binomial distribution is more appropiate than the Poisson.