(1) Background: The management of multiple chronic diseases challenges China’s health system, but current research has neglected how multimorbidity is associated with poor health-related quality of life (HRQOL) and high health service demands by middle-aged and older adults. (2) Methods: A cross-sectional study was conducted in Shandong province, China in 2018 across three age groups: Middle-aged (45 to 59 years), young-old (60 to 74 years), and old-old (75 or above years). The information about socio-economic, health-related behaviors, HRQOL, and health service utilization was collected via face-to-face structured questionnaires. The EQ-5D-3L instrument, comprising a health description system and a visual analog scale (VAS), was used to measure participants’ HRQOL, and χ2 tests and the one-way ANOVA test were used to analyze differences in socio-demographic factors and HRQOL among the different age groups. Logistic regression models estimated the associations between lifestyle factors, health service utilization, and multimorbidity across age groups. (3) Results: There were 17,867 adults aged 45 or above in our sample, with 9259 (51.82%) female and 65.60% living in rural areas. Compared with the middle-aged adults, the young-old and old-old were more likely to be single and to have a lower level of education and income, with the old-old having lower levels than the young-old (P < 0.001). We found that 2465 (13.80%) suffered multimorbidities of whom 75.21% were older persons (aged 60 or above). As age increased, both the mean values of EQ-5D utility and the VAS scale decreased, displaying an inverse trend to the increase in the number of chronic diseases (P < 0.05). Ex-smokers and physical check-ups for middle or young-old respondents and overweight/obesity for all participants (P < 0.05) were positively correlated with multimorbidity. Drinking within the past month for all participants (P < 0.001), and daily tooth-brushing for middle (P < 0.05) and young-old participants (P < 0.001), were negatively associated with multimorbidity. Multimorbidities increased service utilization including outpatient and inpatient visits and taking self-medicine; and the probability of health utilization was the lowest for the old-old multimorbid patients (P < 0.001). (4) Conclusions: The prevalence and decline in HRQOL of multimorbid middle-aged and older-aged people were severe in Shandong province. Old patients also faced limited access to health services. We recommend early prevention and intervention to address the prevalence of middle-aged and old-aged multimorbidity. Further, the government should set-up special treatment channels for multiple chronic disease sufferers, improve medical insurance policies for the older-aged groups, and set-up multiple chronic disease insurance to effectively alleviate the costs of medical utilization caused by economic pressure for outpatients and inpatients with chronic diseases.

(1) Background: The association between multimorbidity and mental health is well established. However, the role of gender in different populations remains unclear. Currently, China is facing an increased prevalence of multimorbidity, especially in its disease-causing poverty population. The present study explores the gender-based differences in the relationship between multimorbidity and mental health using data from the rural, disease-causing poverty, older-age population in Shandong province, China, as a case study. (2) Methods: The data were obtained from the survey on the health and welfare of disease-causing poverty households in rural Shandong province. We identified 936 rural participants who were over 60 years old from disease-causing poverty households. The mental health status was measured using the Kessler Psychological Distress Scale (K10) instrument. Using a multivariable linear regression model, including the interaction of gender and multimorbidity, gender differences in the association between multimorbidity and mental health were explored. (3) Results: Multimorbidity was a serious health problem in rural, disease-causing poverty, older-age households, with the prevalence of multimorbidity estimated as 40% for women and 35.4% for men. There was a strong association between multimorbidity and mental health, which was moderated by gender. Women had higher K10 scores than men, and the mean K10 score was highest in women with three or more chronic diseases. Compared with men, women with multimorbidity had a higher risk of mental health problems. (4) Conclusions: The prevalence of multimorbidity in older-age rural disease-causing poverty subpopulations is a severe public health problem in China. The association between multimorbidity and mental health differed by gender, where multimorbid women suffered an increased mental health risk compared with men. Gender differences should be addressed when delivering effective physical and mental healthcare support to disease-causing poverty, older-age, rural households.