No data on the quality of life (QOL) of the general population are available for Mongolia. This study aimed to determine normative data on the World Health Organization Quality of Life-Brief Version (WHOQOL-BREF) in the general population of Mongolia. This nationwide, population-based, cross-sectional study was conducted in 48 sampling centers across Mongolia in 2020. We used the WHOQOL-BREF and the Hospital Anxiety and Depression Scale (HADS) in our study and evaluated their associations with vital signs, body measurements, and lifestyle determinants. A total of 714 participants (261 men and 453 women) with a mean (standard deviation) age of 40.7 (13.2) years were recruited. The mean scores of WHOQOL-BREF subscales were 61.5 for physical health, 73.5 for psychological health, 70.1 for social relationship, and 67.2 for environmental health domains. The prevalence of poor QOL was 16.9% among the participants. Participants living in an apartment in urban areas with high HADS scores had a low QOL. All domains of WHOQOL-BREF were inversely correlated with anxiety score (r = -0.353 ‐ -0.206, p < 0.001) and depression scores (r = -0.335 ‐ -0.156, p < 0.001). Physical health was predicted by residency location, anxiety, and depression (R² = 0.200, p < 0.001); psychological health by anxiety and depression (R² = 0.203, p < 0.001); social relationship by residency location, age group, anxiety and depression (R² = 0.116, p < 0.001); and environmental health by employment, anxiety, and depression (R² = 0.117, p < 0.001). This is the first report on normative data on the QOL in the general population of Mongolia. Physical health was low compared with that determined using international data. Poor QOL was observed among those with mental health issues living in the urban areas.

Various psychological, biological, and social factors make people vulnerable to mental health problems. These precursory factors as mental distress, are not sufficient alone for diagnosing a mental disorder but are recognised as risks to mental health. There has been no screening tool available in Mongolia that is adequately validated for mental health screening and neuropsychiatric functions of the brain. Therefore, we aimed to translate and validate the hospital anxiety and depression scale (HADS) to identify potential mental distress in healthy people. The HADS is reliable, valid, and practical for identifying the most common psychological disturbances. This nationwide comparative observational study for the validity of a self-reported measure was conducted between June and December 2020. One thousand ninety-four participants were randomly selected, aged 13-75, mean age was 37.7±13.7 years old, 60.9% were females, 63.9% were married. HADS total score was 13.0±5.7, HADS anxiety (HADS-A) score was 6.8±3.6, and HADS depression (HADS-D) score was 6.0±3.1 for the original two-factor model. The external reliability was good in the whole scale, and both subscales using the Intraclass Correlation Coefficient (0.872, 0.837, and 0.801 for the HADS-T, HADS-A, and HADS-D, respectively). Cronbach's alpha value was 0.776, 0.756, and 0.582, respectively, for the HADS-T, HADS-A, and HADS-D, indicating an acceptable internal consistency for the entire scale but marginal reliability for the HADS-D subscale. The reliability of both the two-factor and three-factor structures of the HADS was confirmed using confirmatory factor analysis with a satisfactory model fit on a separate sample. In conclusion, the Mongolian version of the HADS can be considered a valid and reliable measurement tool for various scientific and clinical practices in the general population.