Causes of death in patients with rheumatoid arthritis over a 40-year period : with special emphasis on autopsy

Rheumatoid arthritis (RA) patients have premature mortality. Contrary to the general population, mortality in RA has not declined over time. This study aimed to evaluate determinants of mortality in RA by examining causes of death (CoDs) over time, accuracy of CoD diagnoses, and contribution of RA medication to CoDs. This study further evaluated detection rate of reactive systemic amyloid A amyloidosis, which is an important contributor to RA mortality. CoDs were examined in 960 RA patients between 1971 and 1991 (Study population A) and in 369 RA patients autopsied from 1952 to 1991, with non-RA patients serving as the reference cases (Study population B). In Study population B, CoDs by the clinician before autopsy were compared to those by the pathologist at autopsy to study accuracy of CoD diagnoses. In Study population B, autopsy tissue samples were re-examined systematically for amyloidosis (90% of patients) and clinical data for RA patients was studied from 1973. RA patients died most frequently of cardiovascular diseases (CVDs), infections, and RA. RA deaths declined over time. Coronary deaths showed no major change in Study population A, but, in Study population B, coronary deaths in RA patients increased from 1952 to 1991, while non-RA cases had a decrease in coronary deaths starting in the 1970s. Between CoD diagnoses by the clinician and those by the pathologist, RA patients had lower agreement than non-RA cases regarding cardiovascular (Kappa reliability measure: 0.31 vs. 0.51) and coronary deaths (0.33 vs. 0.46). Use of disease modifying anti-rheumatic drugs was not associated with any CoD. In RA patients, re-examination of autopsy tissue samples doubled the prevalence of amyloid compared with the original autopsy: from 18% to 30%. In the amyloid-positive RA patients, amyloidosis was diagnosed before autopsy in only 37%; and they had higher inflammatory levels and longer duration of RA than amyloid-negative RA patients. Of the RA patients with amyloid, only half had renal failure or proteinuria during lifetime. In RA, most important determinants of mortality were CVDs, RA, and infections. In RA patients, RA deaths decreased over time, but this was not true for coronary deaths. Coronary death being less accurately diagnosed in RA may indicate that coronary heart disease (CHD) often goes unrecognized during lifetime. Thus, active search for CHD and its effective treatment is important to reduce cardiovascular mortality. Reactive amyloidosis may often go undetected. In RA patients with proteinuria or renal failure, as well as with active and long-lasting RA, a systematic search for amyloid is important to enable early diagnosis and early enhancement of therapy. This is essential to prevent clinical manifestations of amyloidosis such as renal failure, which has a poor prognosis.

Optimal multispecies fishery management in the Baltic Sea: A bioeconomic analysis

The aim of the thesis is to assess the fishery of Baltic cod, herring and sprat by simulation over 50 years time period. We form a bioeconomic multispecies model for the species. We include species interactions into the model because especially cod and sprat stocks have significant effects on each other. We model the development of population dynamics, catches and profits of the fishery with current fishing mortalities, as well as with the optimal profit maximizing fishing mortalities. Thus, we see how the fishery would develop with current mortalities, and how the fishery should be developed in order to yield maximal profits. Especially cod stock has been quite low recently and by optimizing the fishing mortality it could get recovered. In addition, we assess what would happen to the fisheries of the species if more favourable environmental conditions for cod recruitment dominate in the Baltic Sea. The results may yield new information for the fisheries management. According to the results the fishery of Baltic cod, herring and sprat are not at the most profitable level. The fishing mortalities of each species should be lower in order to maximize the profits. By fishing mortality optimizing the net present value would be almost three times higher in the simulation period. The lower fishing mortality of cod would result in a cod stock recovery. If the environmental conditions in the Baltic Sea improved, cod stock would recover even without a decrease in the fishing mortality. Then the increased cod stock would restrict herring and sprat stock remarkably, and harvesting of these species would not be as profitable anymore.