Abstract Background To better understand the impact of low testosterone treatments on men with hypogonadism, data on treatment efficacy and safety must be combined with patient-reported outcomes measurements (PROMs). Whether these objective tools conceptualise and measure the impacts of hypogonadism in the same way, is not known. Aim To appraise the evidence on the item content of validated patient-reported outcome measures for hypogonadism evaluations and identify core domains of potential importance in this context. Methods We systematically reviewed tools (e.g., questionnaires, surveys, scales) in published quantitative or qualitative data of men with low testosterone and/or those using (or who had considered treatment). PROMs data extraction forms and data tables were generated for each stage of the extraction process to standardise the information recorded and aid analysis. Data was synthesised by classifying the items identified into domains determined by the nomenclature reported in included studies and the International Classification of Functioning, Disability and Health (WHO-ICF). Finally, a narrative synthesis of the instruments and their inter-related domains and subdomains was conducted to identify areas of both convergence and divergence. Results A total of nine tools measuring PROMs of men with low testosterone were included in this review. The included studies were set within the US (n=5), Canada (n=1), UK (n=1), Germany (n=1), Italy (n=1). The tools identified were: Androgen Deficiency in Aging Males (ADAM) Questionnaire, The Aging Males’ Symptoms (AMS) scale, ANDROTEST ©, The Age-Related Hormone Deficiency Dependent Quality of Life Questionnaire (A-RHDQoL)©, Hypogonadism Energy Diary (HED), Hypogonadism Impact of Symptoms Questionnaire (HIS-Q), HIS-Q-Short Form (HIS-Q-SF), Massachusetts Male Ageing Study (MMAS) questionnaire, Sexual Arousal, Interest, and Drive Scale (SAID). Only HED, SAID, and HIS-Q reported including patients while developing the tool. The number of items varied across instruments and ranged from 3 to 53 items (median=7) with a cumulative total of 98 individual items. The ten domains identified were: Cognition, Energy, General well-being, Mood, Pain, Physical-General, Role, Sexual, Sleep, Social. Across tools, the most frequently identified domain was the sexual domain. However, two of the PROMs, HED and MMAS, did not include any items that covered the sexual domain. Six of the nine tools were considered multi-dimensional, and three were considered unidimensional (i.e. only capturing one domain). The A-RHDQoL tool showed to be the most comprehensive tool across the PROMs included since this was the only one to include items that could be coded to all ten domains. Conclusions This study has demonstrated the considerable item concept variability across disease-specific PROMs for men with low testosterone regarding development and domain coverage. The dominant focus of these PROMs to date has centred around sexual function, but possibly to the detriment of other aspects that also matter to patients. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.