[Changes in the prevalence of disability pension in Iceland 1976-1996.]

To determine changes in the prevalence of disability pension in Iceland and to describe the distribution of those receiving disability pension according to gender, age and main diagnoses between the years 1976 and 1996.

The study includes all those receiving disability pension on the 1st of December in the years 1976 and 1996 as ascertained by the disability register at the State Social Security Institute of Iceland. There are two levels of disability pension, full disability pension (disability assessed as being more than 75%) and reduced disability pension (disability assessed as being 50% or 65%). Information on age and gender distribution of the Icelandic population was obtained. Age-standardized risk ratio between the years 1976 and 1996 was calculated for both pension levels combined and for full disability pension alone.

There was no significant change in crude prevalence rate for both pension levels combined between the years 1976 and 1996, when the increase in the population was accounted for but without paying attention to changes in gender or age distribution. However, the standardized risk ratio showed a significantly decreased risk for both pension levels combined both for men and women in the year 1996 as compared with the year 1976, the age-standardized risk ratio being 0.95 and 0.93 respectively. It also showed a significant change between pension levels with an increased risk of full disability pension and a decreased risk of reduced disability pension. The increase in full disability pension was noted for both males and females and was largely independent of age. There was a significant increase in full disability pension in most disease categories. Disability due to diseases of the nervous system and sense organs and injury and poisoning increased amongst women only. A significant decrease in full disability pension due to infections and diseases of the digestive system occurred in both men and women.

The prevalence of a disability pension amongst men and women in the year 1996 as compared to the year 1976 was significantly decreased when changes in population size and age distribution had been accounted for. This is particularly interesting because unemployment was increasing just prior to the year 1996. The prevalence of full disability pension had however significantly increased in 1996 compared with 1976. A plausible explanation for the observed change in disability pension levels is a pressure from the labour market, with increasing unemployment and competition. Also, the introduction of a disability card for those with full disability pension in 1980, which granted lower price for medication and the services of physicians, is likely to have increased the pressure for the higher level of disability pension (full disability pension). It seems unlikely that the increase in full disability pension and the decrease in reduced disability pension is due to a deterioration of health of the Icelandic population. Increased disability due to injury and poisoning amongst women is probably a result of their increased participation in the labour market. The decrease in disability due to infections is a result of a reduction in the number of cases of tuberculosis and poliomyelitis. The decrease in disability due to diseases of the digestive system is probably a result of improvement in the treatment of oesophageal reflux and peptic ulcer.