Purpose Inability to work fulltime is an important outcome in the assessment of workers applying for a disability benefit. However, limited knowledge is available about the prevalence and degree of the inability to work fulltime, the associations between disease-related and socio-demographic factors with inability to work fulltime and whether the prevalence and the associations differ across disease groups. Methods Anonymized register data on assessments of workers with residual work capacity (n = 30,177, age 48.8 ± 11.0, 53.9% female) applying for a work disability benefit in 2016 were used. Inability to work fulltime was defined as being able to work less than 8 h per day. Results The prevalence of inability to work fulltime was 39.4%, of these 62.5% could work up to 4 h per day. Higher age (OR 1.01, 95% CI 1.01–1.01), female gender (OR 1.45, 95% CI 1.37–1.52), higher education (OR 1.44, 95% CI 1.33–1.55) and multimorbidity (OR 1.06, 95% CI 1.01–1.11) showed higher odds for inability to work fulltime. Highest odds for inability to work fulltime were found for diseases of the blood, neoplasms and diseases of the respiratory system. Within specific disease groups, different associations were identified between disease-related and socio-demographic factors. Conclusion The prevalence and degree of inability to work fulltime in work disability benefit assessments is high. Specific chronic diseases are found to have higher odds for inability to work fulltime, and associated factors differ per disease group.

目的无法全职工作是评估申请残疾福利的工人的一个重要结果。然而，关于无法全职工作的患病率和程度、疾病相关和社会人口因素与无法全职工作之间的关联以及患病率和关联是否因疾病组而异的知识有限。方法使用匿名登记数据对 2016 年申请工作残疾福利的具有剩余工作能力的工人（n = 30,177，年龄 48.8 ± 11.0，53.9% 女性）进行评估。无法全职工作被定义为每天工作时间少于 8 小时。结果无法全职工作的患病率为 39.4%，其中 62.5% 的人每天可以工作 4 小时。更高的年龄（OR 1.01, 95% CI 1.01–1.01）、女性（OR 1.45, 95% CI 1.37–1.52）、更高的教育（OR 1.44, 95% CI 1.33–1.55）和多发病（OR 1.06, 95% CI 1.01–1.11) 显示无法全职工作的几率更高。血液疾病、肿瘤和呼吸系统疾病导致无法全职工作的几率最高。在特定疾病组中，确定了疾病相关因素和社会人口因素之间的不同关联。结论在工作残疾福利评估中，无法全职工作的普遍性和程度很高。发现特定的慢性疾病导致无法全职工作的几率更高，并且每个疾病组的相关因素不同。