A Comorbidity Study Of Depression And Chronic Physical Conditions

Objectives:To investigate the current status of comorbidity between depression and chronic physical conditions,including the prevalence,impact factors,burden of disease and health service utilization of comorbidity.Methods:The study was a cross-sectional survey conducted in 31provinces in China(exclude HongKong,Macao,Taiwan).Double sampling of cluster probability proportional to size was used based on the national disease surveillance points of national disease surveillance survey.The sampling process was divided into seven stages.There were 38593permanent residents above age 18 years old be selected.The Composite International Diagnostic Interview(CIDI-3.0)was used as the main study instrument.The basic information of respondents,the prevalence of depression and 17 chronic physical conditions,lost productivity(days absent from work),burden of disease(SDS,WHO-DAS),stigma and the service utilization could be obtained from CIDI-3.0.The prevalence of depression and chronic physical conditions were analyzed by SPSS 17.0.The t test,one-way ANOVA,post-hoc test(Bonferroni)or chi-square test was applied to compare data difference between different groups.The logistic regression was applied in the analysis of factor interactions.The Synergy Index(SI)was applied to analyze the additive interaction between depression and chronic physical conditions.Results:(1)A total of 28140 respondents finished the CIDI-3.0questionnaire with 72.9%of the overall response rate.The lifetime prevalence of depression was 6.5%(1841 cases),and the 12-month prevalence of depression was 3.5%(969 cases).The lifetime prevalence of at least one of the 17 chronic physical conditions was 45.3%(15071 cases),and the 12-month prevalence of chronic physical conditions was 22.6%(6362 cases).The lifetime prevalence of comorbidity was 4.9%(1368cases),and the 12-month prevalence of comorbidity was 1.6%(449 cases).(2)Female gender(OR=2.13,95%CI:1.66-2.74),older age(OR=2.08~3.02),rural living(OR=1.56,95%CI:1.26-1.93),divorced/widowed(OR=1.56,95%CI:1.11-2.20),overweight(OR=1.36,95%CI:1.09-1.70)or obesity(OR=1.65,95%CI:1.23-2.22),and smoking(OR=1.36,95%CI:1.02-1.81)were risk factors for comorbidity.(3)People with depression had higher12-month prevalence of chronic physical conditions(46.3%)than those without depression(OR=3.53,95%CI:3.07-4.07).Similarly,people with chronic physical conditions(7.1%)had higher 12-month prevalence of depression than those without physical chronic conditions(OR=3.54,95%CI:3.08-4.08).(4)The rate of depression patients with mild(?~2=22.950,P<0.001),moderate(?~2=35.212,P<0.001)or severe(?~2=7.571,P<0.01)disability(SDS)was higher than patients with chronic physical conditions.Chronic physical conditions were more likely to cause severe disability than depression among patients with comorbidity(?~2=12.111,P<0.01).The WHO-DAS score and the risk of disability(WHO-DAS?52)of comorbid patients were both higher than those of patients with depression only or chronic physical conditions only(F=159.472,P<0.001;OR=17.89,95%CI:14.45-22.14).There was interaction effect on disability between depression and chronic physical conditions(SI=1.19,95%CI:1.18-1.61).(5)Patients with chronic physical conditions only lost less productivity(OR=0.43,95%CI:0.32-0.57)and perceived less stigma(OR=0.17,95%CI:0.13-0.22)than those with comorbidity.(6)Patients with comorbid conditions were more likely to visit clinic within 3 months(33.0%;?~2=1333.365,P<0.001)and be hospitalized within 12 months(15.4%;?~2=785.419,P<0.001)than patients with either depression only(20.3%,8.4%)or chronic physical conditions only(23.3%,12.9%).Patients with comorbidity(11.1%,2.9%)were more likely to visit clinic or be hospitalized for depression within 12 months than patients with depression only(4.6%,0.4%)(?~2=9.991,P<0.01;?~2=14.590,P<0.001).Conclusions:Comorbidity between depression and chronic physical conditions was very common.The prevalence of chronic physical conditions was higher among patients with depression than those without depression.Similarly,the prevalence of depression was higher among patients with chronic physical conditions than those without.Depression and chronic physical conditions were interactional risk factors of each other.Female gender,older age,rural living,divorced/widowed,overweight or obesity,and smoking were risk factors for comorbidity.Comorbidity could lead to more severe functional disability and lost productivity.The service utilization of comorbidity patients was high.However,the treatment rate of depression were both low among patients with depression only and with comorbid conditions at low level.