Clinical characteristics and relating factors of somatization symptoms of outpatients with psychological disorders: A cross-sectional observational study

Abstract Background:Cardiovascular disease patients associated with psychological disorders are very common clinically.It has been demonstrated in previous study that a higher prevalence of psychiatric disorders in the patients with CVD than the general population.Anxiety and depression are found to be the most common types of psychiatric disorders in the patients with CVD. Objective:Exploring the clinical characteristics and relating factors of somatization symptoms of the outpatients with psychological disorders. Methods:From August 2017 to July 2018,we used the General Anxiety Disorder-7, Patient Health Questionnaire, Patient Health Questionnaire-15 and self-made general demographic data questionnaire to investigate the outpatients suspected with psychiatric disorders in cardiology department in a general hospital,who were screened with the"three questions"method. Results:Among the 508 effective patients, the total detection rate of anxiety/depression was 81.1% (412/508),and the detection rate of somatization symptoms was 93.1%(473/508).The positive number of PHQ-15 symptom items was 8.54±2.67,and the detection rate of anxiety/depression was 78.7% in 473 patients with somatization symptoms.Among the patients with mild,moderate and severe somatization symptoms,there were signicant differences in the proportion of women, the average number of the patient visits and hospitalizations in the past year(P=0.0341, 0.023),and also in GAD-7 and PHQ-9 scale scores(P=0.0282, 0.0011).Linear correlation analysis showed PHQ-15 score was signicantly correlated with GAD-7(r=0.4787, P<0.001) and PHQ-9 score(r=0.5141, P<0.001).Stepwise logistic regression analysis showed that the PHQ-9,GAD-7 scores and female were positive factors on somatizations. Conclusion:The the


Background
Cardiovascular disease(CVD) patients associated with psychological disorders are very common clinically. Compared with the general population, a higher prevalence of psychiatric disorders in the patients with CVD has been demonstrated in previous study [1,2]. Anxiety and depression are found to be the most common types of psychiatric disorders in the patients with CVD [1,3]. One recent research by Man Zhao et al, showed that the incidence rate of anxiety and depression was 42.5% in the outpatients of cardiology department of general hospitals [4]. Conversely, an association of psychiatric disorders, in particular anxiety and depression, with the development and progression of cardiovascular disease has been con rmed by recent research [1,5,6]. The common psychological problems such as depression and anxiety are often accompanied by somatic complaints including chest pain, fatigue, shortness of breath, dizziness, etc. [7][8][9][10]. Patients lacking insight into psychological problems often consult general practitioners or physical medicine specialists regarding such somatic symptoms [7][8][9]. However, the practitioners in general hospitals have limited ability to recognize and deal with psychological disorders [11]. As a result, persistent somatic symptoms are associated with high medical and societal costs and unmet clinical need [12]. Therefore, it is very important for clinicians to strengthen the identi cation and intervention of psychological problems in general hospitals. To our knowledge, the clinical research on somatization symptoms is rare in the outpatients with CVD in general hospitals.
This present study was aimed to investigate the clinical features and in uencing factors of somatization symptoms of the outpatients suspected with psychiatric disorders in Department of Cardiology in a tertiary general hospital, who complained of physical discomfort and was considered as a suspicious psychological disorder by screened with the "Three Questions" method recommended by the Chinese Expert Consensus on Psychological Prescriptions of Cardiovascular Patients in 2014 [13].

Participants
We recruited the outpatients who complained of physical discomfort and visited the Department of Cardiology at the Xiangya Hospital, Central South University, Changsha, Hunan consecutively from August 2017 to July 2018. Patients who met the both of following criteria were included:1.The both of "three questions "were positive in the "three questions method"in the patient, who was asked to take part in a screening method with the "three questions method" [13] and considered as a suspicious psychological disorder. 2.Patients over 18 years old who were willing to cooperate and were able to complete the scales and questionnaires. Exclusion criteria included:severe hypertension, heart failure above New York Heart Association(NYHA) grade III, severe arrhythmias such as ventricular tachycardia and atrial brillation; somatic diseases such as diabetes mellitus, severe organic brain diseases, dementia and cognitive impairment, hepatic and renal insu ciency, respiratory failure; di culties in communication, language or writing; schizophrenic psychiatric symptoms and severe depression with suicidal tendencies and behaviors; and having taken or being taking related drugs (such as anti-anxiety and depressive drugs, sedative and hypnotic drugs, analgesic drugs, etc.) after the onset of physical symptoms.

Methods
Participants were assisted to complete the following information assessment by the coordinators with certi cate of second-level psychological counselor who received uni ed training: General demographic data:it includes age, gender, marital, status, education, occupation, current disease diagnosed by clinical and electrocardiogram, echocardiogram and other auxiliary examinations, duration of the disease, as well as the medical consultation and treatment for main somatization symptoms in the past one year.
And Table 1

Statistical methods
All data were analyzed with SPSS Version 17.0 (IBM, Armonk, NY). The measurement data of normal distribution were expressed as mean ± SD. The counting Data were described with rank or percentage. According to the data types and distribution characteristics, one-way ANOVA was used to compare the mean between groups, X 2 test used to compare the categorical data and ratios. Linear correlation analysis was adopted for the two-variable relationship, and stepwise logistic regression analysis with the forward conditional method was used for the multi-factor analysis. Bilateral test P<0.05 was considered statistically signi cant.

Results
The occurrence of anxiety/depression and somatic symptoms 538 patients suspected with psychological disorders were found by screened with the"three questions method" [13]. Among them, 30 refused to complete the scales and Questionnaires because of lack of time, unwillingness to disclose personal data and rejection to the self-rated psychological scale. 508 consecutive eligible adult outpatients completed all questionnaires and were recruited in this study.The study protocol was approved by the Ethics Committees of Xiangya Hospital, Central South University and informed consent was obtained from all of the participants. Among the 508 patients, 316 (62.2%) of which were women, age ranged from 18 to 82, with mean age of 51.3 ± 10.1 years old. A total of 278 (54.72%) were diagnosed as cardiovascular diseases, including 138 with hypertension, 30 with unstable angina pectoris, 24 with stable angina pectoris, 56 with arrhythmia such as frequent ventricular premature, frequent atrial premature and short paroxysmal atrial tachycardia; 129 (25.39%) were diagnosed as other somatic diseases, including 56 with chronic gastritis, 34 with multiple lacunar infarction of brain and 36 with cervical spondylosis and other diseases, and 102 cases (20.07%) having no somatic diseases.
Among all the patients with somatization symptoms, the positive number of the items in PHQ-15 was 8.04±2.67, and the total number of patients associated with anxiety or depression symptoms was 400 cases(78.7%). Table 2 showed that the total number of positive PHQ-15 symptoms items in 473 patients with somatization symptoms was 3168, of which 2159 positive items with score = 1 and 1009 items with score = 2. Among the positive PHQ-15 symptoms, more than 50% of the positive symptoms were sleep disorder, chest pain, headache, dyspnea, palpitation, dizziness and nausea, atulence or dyspepsia, while less than 10% were menstrual problems or cramps, sexual pain or dysfunction.
The table 3 showed the characters of patients with somatization symptoms:compared among the three groups of patients with different degrees of somatic symptoms, there was no signi cant difference in the average age, marital status, education level, occupation, the duration of illness and the proportion of current diseases, but signi cant difference was found in the average total score of PHQ-15, the proportion of women, and the average number of outpatient visits and hospitalizations due to the main somatic symptoms within the past one year.
2.4 Comparison of anxiety and depression scores in patients with different degrees of somatization symptoms and analysis of correlation between PHQ-15 score and anxiety or depression As observed in table 4, both anxiety and depression scores increased successively in the patients with somatization symptoms of mild, moderate and severe degrees, and there were statistically signi cant differences between the groups with different degrees of somatic symptoms. The correlation analysis showed that the correlation coe cient between PHQ-15 and GAD-7 scores in the patients with somatization symptoms was 0.4787, with statistical signi cance (P < 0.001); and the correlation coe cient between PHQ-15 and PHQ-9 scores was 0.5141, with statistical signi cance (P < 0.001).

Analysis of predictive factors for somatic symptoms in the patients
Stepwise Logistic regression analysis was performed to analyze the predictive factors for somatization symptoms. Factors with signi cant differences (total score of PHQ-9 and GAD-7) and demographic factors (such as female) were included into the predictive factors for stepwise Logistic regression analysis. Table 5 showed that the score of PHQ-9 and GAD-7 and the female were positive predictive factors for somatization symptoms. The probability of somatization increased by 6.526 and 8.02 times respectively for each 1 point increase in GAD-7 and PHQ-9. The likelihood of female suffering from somatization symptoms increased by 4.440 times. The results indicated that depression, anxiety and female were the predictors of somatic symptoms.

Discussion
The somatization symptoms of patients in general hospitals have become more and more serious clinical and public health problems [17]. Somatization symptoms [18] refers to the experience and presentation of somatic discomfort, which cannot be explained by the knowledge or experience have known.In clinic,disease-related somatic symptoms are different from somatization symptoms, which can be explained by corresponding diseases, and have disease-related clinical characteristics.
Somatization symptoms are quite prevalent in the patients in general hospitals [11,17]. Patients often lack awareness of psychological problems and consider that somatization symptoms are caused by somatic diseases, so they tend to frequently seek the medical service,even visit a tertiary hospital directly. Anxiety and depression are common psychological disorders in outpatients of Cardiology department [4], which are often manifested by various prominent symptoms of cardiovascular somatization, such as "heart distress" or "racing heart". One recent report by Ye Ruifen [19], found that the incidence of somatization symptoms in outpatients of cardiology was as high as 64.2%.
The present study was different from the published reports. Firstly, the object in the study was not all outpatients in cardiology department, but the ones suspected with psychological disorders, screened by the "three questions" [13], were selected as object in the study. Secondly, the three Chinese versions of GAD-7, PHQ-9 and PHQ-15 recommended by DSM-5 were used as research tools in this study. Several previous studies [16,20,21] con rmed that the three scales could be used to screen anxiety, depression and somatization symptoms and assess the severity of anxiety, depression and somatization with good validity and reliability respectively in general hospitals in China.
The results of this study showed that the total detection rate of anxiety/depression and somatization symptoms was 81.1% and 93.1% respectively in the participants. This nding further con rmed that the "three questions" method [13] had a high validity for the initial screening of psychological disorders. This study also suggested that the incidence of somatization symptoms in the patients screened by "three questions" method [13] is much higher than that of 64.2% in the total outpatients in cardiology clinics [19].
This study found the average number of positive items of symptoms in PHQ-15 was 8 more than in the patients with somatization symptoms. Observing from the positive items of PHQ-15 symptoms, the common items are ones related with cardiovascular diseases such as chest pain, palpitation, dyspnea.
The positive items also included ones with nervous system such as headache, dizziness, and ones with digestive system such as gastralgia, abdominal distention.It was worth noting that the incidence of sleep disorder in PHQ-15 items was as high as 77.38%, which indicates that sleep disorder was an important clinical feature of somatization symptoms in outpatients with psychological disorders in cardiology department.Item 4 (menstrual problems), and item 8 (sexual problems) displayed extreme oor effects. These oor effects were also found in previous Chinese and Western studies [22,23], which may be related to the in uence of Chinese traditional culture and the patients' lacking attention or unwillingness to express.
The results showed that anxiety and depression in patients with somatization symptoms were mild to moderate, and not all patients with somatization symptoms could meet the criteria of anxiety and depression by GAD-7 and PHQ-9 scales. In this study, the total detection rate of anxiety/depression in the patients with somatization symptoms was only 78.7%, whereas 21.3% of the patients were negative.
The reason for negative results of anxiety/depression test in the patients with somatization symptoms [24,25] may be as follows:(1)Anxiety/Depression Scale is compiled by psychologist, and its items mainly re ect psychological mood and symptoms; (2)patients often suffer from mild or moderate psychological disorders and are mainly concerned about their somatization symptoms; (3)Because of many factors including the stigma, patients often have a denial and exclusion attitude towards psychological and emotional problems, even if they have psychological and emotional problems, they will also neglect it. The study by Greden' [26] suggested that 69% of depressive patients complained only of somatic symptoms. Even when asked directly, 11% of them denied having any psychological symptoms of depression.
A lot of recent reports [17,19,27] on the occurrence and in uencing factors of somatization symptoms in outpatients of general hospitals has con rmed that somatization symptoms are closely related to anxiety and depression. In the present study, the results showed that the scores of GAD-7 and PHQ-9 increased with the degree of somatization symptoms, and there were signi cant differences among different degrees of somatization symptoms in GAD-7 and PHQ-9 scores. There were no signi cant differences in average age, marital status, education level, occupation, duration of illness and the proportion of current illness except for the proportion of women in different degrees of somatization symptoms.
Stepwise logistic regression analysis also found that the total scores of PHQ-9 and GAD-7 and female were the positive correlative factors of somatization symptoms.The results of our study were consistent with the relevant researches [17,19,27], it further reveals that anxiety, depression and gender are the main predictive factors for somatization symptoms of outpatients in cardiology department of general hospitals. The correlation mechanism between somatization symptoms and anxiety and depression[28, 29] may be as follows:(1)Depression and anxiety are the most common direct causes of somatization, that is, patients mainly adopt somatic response rather than cognitive response when they are activated by mental stimulation. Somatization symptoms can be considered as the manifestation of anxiety and depression. (2)Depression and anxiety are the inducing or triggered factors of somatic diseases, such as hypertension and coronary heart disease. (3)Anxiety and depression may be a direct consequence of somatic diseases. (4)Anxiety and depression may aggravate the symptoms associated with physical diseases. Besides, the female is the in uencing factor of somatization symptoms,and it may be related to the character of female, social and family status, and Chinese cultural traditions.
The present study has several limitations. First, this study was a single-center cross-sectional study. Our study sample consisted of the patients who visit the cardiology department in a tertiary hospitals and were initially screened as psychological disorders. Therefore, the results may be representative of somatization symptoms of patients suspected with psychological disorders. Second, the diagnosis of somatic diseases in a small number of patients was based on the patient's statement without con rmed by corresponding objective examinations. Finally, most of the patients were self-paid because of the medical insurance, and some patients were reluctant to disclose their personal or family nancial situation when they completed general information. Therefore, this study did not include the economic status and means of payment of medical cost. One recent study by Xu W, et al, [30] found that whether outpatient expenses could be reimbursed was one of the in uencing factors for somatization symptoms.

Conclusion
In conclusion, the incidence of somatization symptoms is high in patients with psychological disorders in outpatients of cardiology department of general hospitals. Anxiety, depression and gender are the main affecting factors on somatization symptoms. Early recognition and correct diagnosis of somatization symptoms in the patients with psychological disorders could lead to appropriate treatment and health care cost reduction. These results may help cardiologists in the general hospitals to diagnose and manage patients with psychological disorders appropriately.