This thesis explores the use of observational microdata in cost-effectiveness analysis. The application of econometric methods adjusting for selection bias is first reviewed and critically appraised in the economic evaluation literature using a structured template. Limitations of identified studies include lack of good quality evidence regarding the performance of different analytical approaches; inadequate assessment of the sensitivity of their results to violations of fundamental assumptions or variations to crucial estimator parameters; failure to combine the cost and effectiveness outcomes in a summary measure; and no consideration of stochastic uncertainty for the purpose of evaluating cost-effectiveness. Data from the Birthplace national cohort study are used in an attempt to address these limitations in the context of an empirical comparison of estimators relying on regression, matching, as well as the propensity score. It is argued that although these methods cannot address the potential impact of unobservable confounding, a novel approach to bias-corrected matching, combining entropy balancing with seemingly unrelated regression, still has the potential to offer important advantages in terms of analytical robustness. The net economic benefit is proposed as a straightforward way to exploit the strengths of rigorous econometric methodology in the development of reliable and informative cost-effectiveness analyses.

Depresija yra vienas iš dažniausių psichikos sveikatos sutrikimų, ir neretai sergantiesiems depresija tuo pat metu pasireiškia ir nerimo sutrikimai. Psichologinis atsparumas yra susijęs su bendra psichinės sveikatos būkle - asmenys su psichikos sutrikimais turi žemesnį atsparumą. Atsparumas yra kintantis ir gali būti pagerintas gydymu. Psichoterapijos dienos stacionaras apima intensyvią, bet trumpalaikę psichoterapinę ar kombinuotą pagalbą ir yra ypatinga, tarpinė tarp hospitalizacijos ir ambulatorinio gydymo grandis. Šiame darbe siekėme išsiaiškinti psichoterapijos dienos stacionaro pacientų su neuroziniais ir afektiniais sutrikimais gydymo efektyvumą ir sociodemografinių veiksnių, psichopatologinių simptomų, psichologinio distreso, motyvacijos psichoterapiniam gydymuisi ir psichologinio atsparumo ryšius bei pokyčius laikui bėgant. Buvo tirti psichoterapijos dienos stacionare besigydantys pacientai su afektiniais ir neuroziniais sutrikimais. Atliktas longitudinis trijų etapų tyrimas. Rezultatai parodė, kad gydymo metu ir po jo psichopatologinių simptomų, distreso, motyvacijos psichoterapiniam gydymuisi ir psichologinio atsparumo išreikštumas statistiškai reikšmingai kito; nustatyti reikšmingi skirtumai tarp pacientų su afektiniais ir neuroziniais sutrikimais bei tarp psichoterapiniu ir kombinuotu būdu gydytų pacientų. / Depression is one of the most common mental health disorders, and patients who suffer from depression at the same time often also experience symptoms of anxiety disorders. It was found that individuals who developed psychopathological symptoms were characterized by significantly lower resilience. Resilience was changeable and could be improved by treatment. Treatment in a Psychotherapy Day-Care Centre included an intensive but short-term psychotherapy or combined help, and was a special, partial hospitalization programme, in-between hospitalization and outpatient treatment. Aim of the study was to estimate the effectiveness of the treatment for patients with neurotic and affective disorders at the Psychotherapy Day Care Centre, and establish the relationships and changes over time of sociodemographic factors, psychopathological symptoms, psychological distress, motivation for psychotherapeutic treatment and psychological resilience. The patients with Neurotic and Mood (affective) disorders who were receiving treatment in Psychotherapy Day Care Centre were tested. The study was longitudinal – it consisted of three evaluative stages. We found out that the expression of the psychopathological symptoms, distress, motivation and resilience significantly changed during and after the treatment. Significant differences were established between the patients with affective and neurotic disorders and between the patients treated by psychotherapy and combined treatment.