Econometric analysis of oncology patients' Health-Related Quality of Life determinants in Bulgaria

The present study investigates the determinants of oncology patients' Health-Related Quality of Life (HRQoL) in Bulgaria. Looking at some patients' characteristics, including control variables in the estimated model - demographics and the time from the disease onset, it studies the relevance of HRQoL diverse factors: some of them are related to the physical and psychological dimensions of the patients' illness experience, such as the levels of pain and anxiety/depression; some other concern more specifically the patients' therapeutic path, i.e., the feeling of participation in the therapy, their perceived uncertainty in illness (predictability and complexity), and the quality of the information received from the nurses and other medical personnel.

A questionnaire collecting information on HRQoL, uncertainty in illness and patients' experience with the hospital treatment has been administered to 306 oncology patients at four oncology centres in Bulgaria. Data has then been employed in the estimation of a Tobit model: the dependent variable selected has been the variation in the Visual Analogue Scale (VAS) score. The econometric model takes into account the characteristics of censoring in the dependent variable.

Overall, the coefficients estimated, and the regression itself showed a good level of significance. Some dimensions of EuroQol-5D (EQ-5D) questionnaire - pain and anxiety/depression - have a significant impact on HRQoL, as well as some features of uncertainty in illness, as unpredictability and complexity. As expected, the longer the time elapsed from the diagnosis, the higher the reported HRQoL; the value of the information provided to the patients by the nurses as well as physicians is also relevant.

This study presents an analysis of the impact of uncertainty in illness, feeling of participation in the therapy, and communication with the hospital personnel on oncological patients' HRQoL, which increases the scanty evidence referring to the patient-centred care in the Bulgarian hospital setting. Further deepening might concern a wider sample, including data collected at other medical centres and/or in other geographical areas in Bulgaria as well as in other European countries.