OBJECTIVES: POSSIBLE EU® is an ongoing, prospective observational study exploring the experience of postmenopausal women receiving bone loss medications in Europe. We previously reported that these women had substantially impaired HRQoL. This baseline analysis identifies potential important predictors of HRQoL in these women. METHODS: A total of 3402 women were enrolled in 3 treatment cohorts: established (treated  ≥1 year), inception (initiating) or switching treatment. Clinical data and HRQoL (including EQ-5D) were collected at baseline (N = 3011). A multivariable analysis model was fitted to identify determinants of EQ-5D score. The linear relationship of each variable was assessed using a forward selection process (entry level 0.05). The non-linear relationship of the selected variables with the outcome, were assessed using natural logarithmic and cubic spline transformations Analyses were performed using SAS software, version 9.1 and GNU R. RESULTS: For the full analysis set, median age (Q1, Q3) was 69 (61, 76) years; women had a median of 3 ongoing comorbid conditions at baseline. A high proportion of patients had hypertension (44%), ongoing back pain (41%), osteoarthritis (34%) hyperlipidaemia (32%), ongoing upper GI issues (18%), prior vertebral fractures (13%), and depression (13%). For the 3011 patients, 12 variables were significantly associated with EQ-5D score, explaining 39.4% of the residual variance (Table). CONCLUSIONS: In European women who are receiving/initiating bone loss medication, any prior vertebral fracture, ongoing depression, fear of falling, number of ongoing comorbid conditions, upper GI issues and back pain are prevalent, and strongly predictive, of lower HRQoL.  Table: Determinants of EQ-5D utility [0 to 1 continuous score]:  The effects are Intercept: 0.1801, -0.1083, 0.486, 0.2195; Inception vs. Established*: -0.04862, -0.06822, 0.02903, <.0001; Switch vs. Established*: -0.01271, -0.03901, 0.01360, 0.3435; Lack of fear of falling: 0.00545, 0.005092, 0.005808, <.0001; Ongoing depression: -0.1076, -0.1345, -0.08076, <.0001; Any prior vertebral fractures: -0.09239, -0.1225, -0.06223, <.0001; Number of ongoing comorbid conditions: -0.01122, -0.01773, -0.00471, 0.0007; Ongoing upper GI (GERD, reflux, dyspepsia): -0.04067, -0.06549, -0.01586, 0.013; Ongoing back pain: -0.03455, -0.05594, -0.01316, 0.0016; BMI: -0.00298, -0.0049, -0.00105, 0.0024; Ongoing seizure disorders: -0.1263, -0.2265, -0.02604, 0.0136; (Log) Number of previous fractures: 0.02572, 0.004297, 0.04713, 0.0186; (Log) Age: 0.07413, 0.008808, 0.1394, 0.0261; Ongoing congestive: 0.06264, 0.006147, 0.1191, 0.0298 for Parameter Estimate, Lower 95% CI, Upper 95% CI, P value, respectively.  *Cohort p<0.0001 Defined by OPAG. Investigator site included as a random effect.