y Health-Related Quality of Life and Healthcare Resource Use: Comparison of Patients with Bipolar I Disorder and Potentially Misdiagnosed Depression

Abstract Background Bipolar I disorder (BP-I) is associated with a high humanistic and economic burden. Evidence suggests that BP-I is often misdiagnosed as major depressive disorder (MDD), but the unmet needs associated with BP-I misdiagnosis are unknown. This study compares socioeconomic, healthcare-related quality of life (HRQoL), and healthcare resource utilization (HRU) burdens of participants diagnosed with BP-I vs participants who screened as probable for BP-I but were diagnosed only with MDD. Methods Using responses to the 2020 National Health and Wellness Survey, respondents were categorized into cohorts of potentially misdiagnosed BP-I (i.e., self-reported physician diagnosis of MDD but screened as probable BP-I [mBP-I]) or BP-I (i.e., self-reported physician diagnosis of BP-I, stratified by BP-I severity). Baseline characteristics were evaluated using bivariate analyses. HRQoL (Short Form-36v2 Health Survey [SF36v2] mental and physical component scores, EuroQol Five-Dimension Visual Analogue Scale [EQ-5D VAS]), HRU, were evaluated using multivariable analyses adjusting for key baseline differences. Results There were 302 respondents in the mBP-I cohort and 818 in the BP-I cohort (mild=336, moderate=285, severe=197). Adults with mBP-I were similar in age and level of depression and anxiety to those with moderate and severe BP-I. With respect to HRQoL, the mBP-I cohort had significantly worse SF36v2 mental component scores and EQ-5D VAS scores vs the mild BP-I cohort (31.3 vs 40.3 [ P <.001] and 60.6 vs 69.4 [ P =.01], respectively) and statistically similar scores vs the moderate BP-I cohort. SF36v2 physical component scores were statistically similar to those of the mild BP-I cohort. Respondents with mBP-I reported similar rates of provider (5.5 vs 6.1 [ P =.63]) and ER visits (.34 vs .40 [ P =.59]) to patients with mild BP-I (but significantly fewer hospitalizations: .08 vs .19 [ P =.03]). Conclusions Respondents with mBP-I exhibited similar HRQoL scores to those with mild to moderate BP-I. As expected for patients without a formal BP-I diagnosis, HRU was lower for mBP-I patients than moderate or severe BP-I, but comparable with mild BP-I. These results suggest that patients with potentially misdiagnosed BP-I may experience considerable HRQoL and HRU burdens akin to those of patients with mild to moderate BP-I. Funding AbbVie