The estimation of the prevalence of multimorbidity and identification of high-risk populations can directly affect the corresponding rational allocation of public health resources.

To comprehensively describe the prevalence trends and population characteristics of multimorbidity among residents in mainland China from 1998-2019 through Meta-analysis.

The databases including Web of Science, PubMed, CNKI, Wanfang Data Knowledge Service Platform and VIP were searched for journal literature relevant to the prevalence of multimorbidity in mainland China from inception to 2022-04-30. Data extraction and quality evaluation were performed on the literature and meta-analysis was performed using Stata 14.0 software. The pooled prevalence of multimorbidity was calculated by using random effects model, and subgroup analysis of the prevalence of multimorbidity was conducted based on survey time (before 2004, 2004-2013, since 2014), gender, region (urban, rural), geographical area (east, central, west, northeast), education level (uneducated, primary school, secondary school and above), marital status (married, others), and research quality (low, medium, high) .

A total of 123 papers were included into analysis with a total sample size of 7 714 313 cases. There was significant heterogeneity among studies (I²=100.0%, P<0.001), and the prevalence of multimorbidity was 36.3%〔95%CI (32.8%, 39.9%) 〕. Meta-linear regression model showed a non-linear increasing trend in the prevalence of multimorbidity from 1998 to 2019〔β=0.013, 95%CI (0.006, 0.019) 〕. The results of the subgroup analysis showed that the prevalence of multimorbidity was higher since 2014〔40.4%, 95%CI (33.0%, 47.8%) 〕 than before 2004〔14.5%, 95%CI (12.5%, 16.5%) 〕 and 2004-2013〔35.2%, 95%CI (32.2%, 38.2%) 〕 (P<0.001) ; the prevalence of multimorbidity was higher among those aged 60-79 years〔38.1%, 95%CI (34.6%, 41.5%) 〕 than those aged ≥80 years〔36.6%, 95%CI (32.5%, 40.8%) 〕, 40-59 years〔27.7%, 95%CI (24.4%, 31.1%) 〕, and <40 years〔10.6%, 95%CI (9.0%, 12.3%) 〕 (P<0.001). There was no significant difference in the subgroup analysis of gender, education level, marital status, region, geographical area, type of chronic disease, quality of research, and the comparison of the prevalence of multimorbidity (P>0.05) .

The prevalence of multimorbidity among residents in mainland China was 36.3% from 1998 to 2019 with a rising trend and significant differences in age, therefore, attention should be paid to the early screening of high-risk population, active and effective strategies for prevention and control should be adopted.

慢性病共病患病率的估计以及高风险人群的识别，直接影响了相应的公共卫生资源的合理分配。

本研究采用Meta分析方法全面描述了1998—2019年中国大陆地区居民慢性病共病的患病趋势和人群特点。

在Web of Science、PubMed、中国知网、万方数据知识服务平台和维普网等数据库从建库截至2022-04-30收录的有关我国大陆地区居民慢性病共病患病率的期刊文献，对文献进行数据提取和质量评价。采用Stata 14.0软件进行Meta分析。运用随机效应模型计算合并患病率，并按照调查时间（2004年以前、2004—2013年、2014年及以后）、性别、地区（城镇、农村）、地域（东、中、西、东北）、年龄（<40岁、40~<60岁、60~<80岁、≥80岁）、受教育水平（未受过教育、小学、中学及以上）、婚姻状况（已婚、其他）、慢病类型（生理类、身心共患类、未区分）、研究质量（低、中、高）对慢性病共病患病率进行亚组分析。并进一步通过元回归模型分析慢性病共病患病率的时间变化趋势。

共纳入123篇文献，总样本量7 714 313例。各研究间存在显著异质性（I²=100.0%，P<0.001），慢性病共病患病率为36.3%〔95%CI（32.8%，39.9%）〕。Meta线性回归模型显示1998—2019年中国大陆地区居民慢性病共病患病率呈非线性上升的趋势〔β=0.013，95%CI（0.006，0.019）〕。亚组分析结果显示，2014年及以后〔40.4%，95%CI（33.0%，47.8%）〕慢性病共病患病率高于2004年以前〔14.5%，95%CI（12.5%，16.5%）〕、2004—2013年〔35.2%，95%CI（32.2%，38.2%）〕（P<0.001）；60~<80岁人群〔38.1%，95%CI（34.6%，41.5%）〕慢性病共病患病率高于≥80岁〔36.6%，95%CI（32.5%，40.8%）〕、40~<60岁〔27.7%，95%CI（24.4%，31.1%）〕、<40岁人群〔10.6%，95%CI（9.0%，12.3%）〕（P<0.001）。性别、受教育水平、婚姻状况、地区、地域、慢病类型、研究质量的亚组分析，组间慢性病共病患病率比较，差异均无统计学意义（P>0.05）。

1998—2019年中国大陆地区居民慢性病共病患病率为36.3%，且慢性病共病患病率呈上升趋势，并具有显著的年龄特征差异，需重视共病高危人群的早期筛查，采取积极有效的策略预防和控制。