Background: Multiple sclerosis (MS) is a chronic disease that is associated with a variety of MS-specific symptoms. Many of these symptoms have a negative impact on health-related quality of life (HRQoL). Until now it is unclear which MS-specific symptoms have the highest impact on the HRQoL.

Methods: The study is based on the data of a member survey of the German MS Society (DMSG) in 2015 (n = 424). Considering socio-demographic variables and general medical variables, the influence of MS-specific symptoms on HRQoL was examined. The HRQoL was collected using the Multiple Sclerosis Quality of Life-54 (MSQOL-54) instrument. In a pretest, all influencing variables were tested for a significant mean difference (p = 0.05), or a mean correlation (Pearson's r ≥ 0.3). Subsequently, the influence of the variables identified in the pretest on the HRQoL was investigated by multiple linear regression analysis.

Results: We calculated a mean physical health composite score (PHCS) of 48.3 (sd = 17.7) and a mean mental health composite score (MHCS) of 56.0 (sd = 20.1). The most fundamental factors influencing HRQoL were the MS-specific symptoms of depression, pain and cognitive impairment. MS-related symptoms with a mobility context showed declining PHCS. Speech disorder and dizziness were associated with a decreasing MHCS. Employment status was the only socio-economic factor that significantly affected HRQoL in multiple regression. The general medical factors showed no significant influence on HRQoL.

Conclusions: MS-specific symptoms have a major impact on the HRQoL of people with MS. Our study show that especially the so-called 'hidden symptoms' such as the symptoms of depression, pain and cognitive impairment have a significant influence on the HRQoL. Greater attention should be paid to these in the care of people with MS.