Abstract This thesis discusses the age and sex distribution of previously hospitalised asthmatics and the number of new asthma-induced treatment periods as a proportion of all asthma-related hospital admissions. Seasonal fluctuations in treatment periods were analysed with respect to age, and seasonal fluctuations in mortality among previously hospitalised asthmatics by combining the hospital discharge register with the mortality statistics on the basis of the patients social security numbers. A total of 364,871 asthma-induced treatment periods were reported to the hospital discharge register in 1972-1992, of which 192,195 occurred in 1.1.1983-31.12.1992, and 28.6% of these were new cases. Treatment periods relative to population amounted to 2.76/1000 in 1972 and 3.43/1000 in 1992. The number of treatment periods among children was greatest at the age of 1 year, 11.2/1000 for boys and 5.5/1000 for girls, and lowest at 17 years among the boys, and 13 years among the girls. The numbers rose slowly in early adulthood (with the exception of men aged 18-22 years), reaching a new peak at 73 years of age for men, 10.3/1000, and 75 years for women, 9.5/1000, and decreasing gradually thereafter. A half of the treatment periods recorded for patients aged under 1 year or for men aged 20 years represented new cases, whereas otherwise the vast majority of the treatment periods were being readmissions. The seasonal peaks among the total of 59,624 hospital periods involving persons aged under 15 years reported to the discharge register in 1972-1992 occurred in May and October, and the lowest figures in January and July. Conscripts aged 18-22 years experienced 4894 asthma-induced treatment periods in 1982-1992, representing incidence rates of 8.5/1000 in 1982 and 27.7/1000 in 1992. The figure was highest in the month in which the conscripts entered service and the month following that. A total of 81,243 asthma-induced treatment periods were recorded for persons aged over 24 years in 1987-1992, the figures being highest in January-May, 18.2% above the monthly trend in January, and lowest in July, 26.1% below the monthly trend. 7622 of the asthmatics first admitted in 1977-1992 died at an age of over 24 years in 1987-1993, mortality being highest in December and January and lowest in August. Obstructive pulmonary diseases were the primary cause of death for 1283 persons, including 489 who died of asthma itself. Apart from children and men aged 18-22 years, asthma gives rise to a large number of treatment periods among the middle-aged and the elderly. Measures should be taken to diagnose it at an early stage in these groups and to intensify the treatment provided. In addition, the factors provoking asthma during military service should be minimised and preventive measures enhanced in the case of children in May and September. As far as adults are concerned, asthma-related hospitalisation may involve a greater fatality risk in winter, so that aggravations occurring in winter should be treated with particular care.

Abstract The purpose of this work was to determine on the basis of the national hospital discharge register and cause-of-death statistics the extent of the hospital treatment required for chronic obstructive pulmonary disease (COPD) in Finland over the period 1972–2001, i.e. the use made of hospital services, factors affecting the length of stay in hospital and the correlation of length of stay with the prognosis. Different intervals within this period were taken for study according to the themes of the individual papers. The results suggest that the length of stay in hospital varies both geographically and seasonally in Finland, the shortest times being recorded in Northern Finland in summer. The main explanations for this would appear to lie in regional differences in health care resources and treatment practises and in climatic variations. The mean length of stay in hospital in the total material in 1987–1998 was nine days. The longest periods applied to cases with concurrent pneumonia or a cerebrovascular disorder. The duration of treatment for the exacerbation stage of COPD decreased by two days between 1993 and 2001, with the longest periods of treatment observed in the case of elderly women. One week of treatment with current modalities may be regarded as optimal, as this was associated with the longest interval before the next exacerbation, just over six months. About 3% of all emergency admissions ended in death, most commonly on a Friday in winter or spring. Patients admitted at a weekend died within the first 24 hours more frequently than did those admitted on a weekday. The mean duration of treatment and frequency of hospitalization increased towards the terminal stage. About one fourth of the patients had died within a year of the first admission for COPD and about a half within five years. Hospital treatment for COPD intensified in Finland during the 1990s as the numbers of hospital beds decreased. Treatment times became shorter and deaths in hospital during exacerbation became less frequent. It will be necessary from now onwards, however, to anticipate the ageing of the population and to develop treatment modalities to replace hospitalization, in order to reduce the costs accruing from this disease. Early diagnosis and outpatient rehabilitation should be developed, and special attention should be paid to appropriate treatment at the terminal stage. / Tiivistelmä Tutkimuksen tarkoituksena oli selvittää valtakunnallisen hoitoilmoitusrekisterin ja kuolemansyytilaston avulla keuhkoahtaumataudista (KAT) aiheutunutta sairaalahoitoa Suomessa 1972–2001: sairaalapalvelujen käyttöä, hoitojakson pituuteen vaikuttavia tekijöitä sekä hoitoajan yhteyttä ennusteeseen. Lähdeaineistosta valittiin erilaisia ajanjaksoja tutkimusasetelman mukaan. Tulokset viittaavat siihen, että hoitoajan pituus vaihtelee Suomessa maantieteellisesti ja vuodenaikojen mukaan: lyhyin hoitoaika on Pohjois-Suomessa kesällä. Ilmiötä selittänevät pääosin terveydenhuollon resurssien ja hoitokäytäntöjen alueelliset erot sekä ilmasto-olosuhteiden vaihtelu. Vuosina 1987–1998 keskimääräinen hoitoaika koko aineistossa oli yhdeksän vuorokautta. Jos potilaalla oli samanaikaisina sairauksina keuhkokuume tai aivoverenkiertohäiriö, nämä johtivat pisimpiin hoitoaikoihin. KAT:n pahenemisvaiheen hoitoaika lyheni kaksi vuorokautta vuodesta 1993 vuoteen 2001. Iäkkäitten naisten hoitoajat olivat pisimmät. Viikon pituinen hoitoaika nykyisillä hoitomuodoilla oli optimaalinen, sillä tällöin aika seuraavan pahenemisvaiheen hoitojakson alkuun oli pisin: vähän yli puoli vuotta. Kaikista päivystyshoitojaksoista potilaan kuolemaan päättyi kolmisen prosenttia. Yleisimmin tällainen hoitojakso päättyi potilaan kuolemaan perjantaisin ja todennäköisimmin talvella tai keväällä. Viikonloppuna sairaalaan tulleista potilaista kuoli ensimmäisen vuorokauden aikana enemmän kuin arkipäivinä tulleista. Keskimääräinen hoitoaika oli pisin ja sairaalahoito runsainta sairauden loppuvaiheessa kuoleman lähestyessä. Ensimmäisen KAT:n aiheuttaman hoitojakson jälkeen noin neljännes potilaista oli kuollut vuoden sisällä ja viiden vuoden kuluessa noin puolet. Keuhkoahtaumataudin sairaalahoito on tehostunut Suomessa 1990-luvulla sairaansijojen vähentyessä. Hoitoajat ovat lyhentyneet ja pahenemisvaiheiden sairaalakuolleisuus on vähäistä. Väestön ikääntyminen on kuitenkin ennakoitava ja sairaalaa korvaavia hoitomuotoja kehitettävä taudista aiheutuneiden kustannusten hillitsemiseksi. Varhaisdiagnostiikkaa ja avokuntoutusta on kehitettävä ja erityinen huomio kiinnitettävä sairauden loppuvaiheen asianmukaiseen hoitoon.