The dominant status relies on the qualitative data as the interviews are emphasized as the best suited method to address the primary aim of this study. The interviews follow a semi-structured interview guide for patients and for caregivers.

Information about socio-economic conditions, disease and treatment variables will be obtained by the investigator at baseline. Disease, treatment and clinical variables will be collected including the World Health Organization (WHO) performance scale (PS) which will be obtained by medical chart review. The self-reported questionnaires (quantitative data) are viewed as a useful supplemental data source, and embrace the topics as distress, anxiety and depressive symptoms.

Theoretical Framework The qualitative and quantitative research components represent different paradigmatic traditions including diverse ontological, epistemological and methodological assumptions. However, these paradigms are not necessarily incompatible. This study applied a pragmatic paradigm, reflecting a pluralistic view using both inductive and deductive reasoning. Applying a qualitative perspective, the present interviews seek to capture the subjective experiences of the study participants related to their life situation.

Analysis The semi-structured interviews will be recorded and transcribed in full length by the interviewer. Interview data will be transferred to NVivo 10 (qualitative data analysis computer software package) software program. A thematic analysis will be conducted for the analysis of the semi-structured interviews. Thematic analysis is a basic method for qualitative analysis as it identifies, analyzes and reports themes and patterns within data. The findings will be presented in themes and subthemes. A theme is an expression or context being defined as important by the researchers. In this study a theme is not necessarily dependent on quantifiable measures, but rather captures an important meaning in relation to the research questions and aims. Data from the interviews are descriptive in nature and reflect the subjective experience of the life situation of patients with HGG and their caregivers. The steps for thematic analysis are inspired by Braun and Clarke and as follows; Step 1) Data are transcribed immediately after an interview by the investigator or a research assistant. Transcriptions are read several times until the investigators are familiar with the depth and extent of the content. This process guides the investigators to the next level of analysis. Step 2) The text is read and divided into units of meanings, which are identified by the investigators. Some meaning units are sentences, others a whole paragraph. In this process data are coded in order to organize them into meaningful groups. This process assures that the whole dataset is systematically worked through by the investigators. Step 3) Then, the codes are analyzed in order to consider if different codes can be combined into mutual themes. This three step process will result in a collection of themes and sub-themes.

Statistical analysis The PS, the The Hospital Anxiety and Depression Scale (HADS) sub-scales, the The Functional Assessment of Cancer Therapy, General and brain cancer (FACT-G and FACT-Br) sub-scales and the responses to the ordinal items of the leisure time physical activity scale will be analysed separately. Socio-economic information and data from questionnaires will be entered into a database. The questionnaires will be analyzed according to their manuals. Categorical variables will be reported as frequencies and percentages, while continuous variables are reported as mean and standard deviations (s.d.) using a significance level of p\\0.05. HADS and FACT-Br data refer to the normative values. The statistical analysis will be performed with SAS (Statistical Analysis System) statistical software, version 9.3.