This study was conducted in the Tianjin area. The patient population focused on outpatients with hyperuricemia and gout visiting a large tertiary hospital in Tianjin from September 2022 to May 2024. The control group consisted of community residents who had been working and living in Tianjin for a prolonged period and individuals who underwent health checks at the same hospital. The studies involving human participants were reviewed and approved by the Ethics Committee of the Tianjin Union Medical Center (Fast Review No. B137 of 2024). The participants provided their written informed consent to participate in this study. The inclusion of the patient group and the general population in this study met the following criteria: (i) age ≥18 years; (ii) residents who had been working or living in Tianjin for a long time; (iii) no cognitive dysfunction and could complete the questionnaire by themselves; and (iv) participated freely in the study. The following exclusion criteria were applied: (i) age <18 years; (ii) residents seeking medical treatment in a different location or those who could not live in Tianjin for a prolonged period time; (iii) Those with cognitive dysfunction or mental illness are not allowed to read the questionnaire by themselves.

This study adopted cross-sectional research model and the researchers and respondents were investigated “face-to-face.” A total of 171 patients with hyperuricemia and gout were included in the study. The information collected from the included population consisted of demographic characteristics and relevant clinical information (sex, age, ethnicity, marital status, educational background, and occupation) Monthly income, medical insurance status, smoking history, drinking history, family history of chronic diseases, staying up late, personal disease history, BMI index, triglyceride level, preference for seafood, duration of hyperuricemia and gout, severity of hyperuricemia and gout. The sampling time for the control group was the same as that for the disease group, and the number of people in both groups was the same, with no differences in age or sex. Both study groups completed the SF-6Dv2 scale through face-to-face interviews. The patient group and the control group were matched according to age and sex to evaluate the applicability of the Chinese version of the SF-6Dv2 scale in assessing the quality of life of gout patients with hyperuricemia in Tianjin and to explore related influencing factors associated with quality of life.

This study used the simplified version of the SF-6Dv2 scale developed for the Chinese population. Compared with other HRQoL scales, respondents spent less time completing this scale. This scale has been verified previously. The respondents indicated that there was no comprehension barrier during the process of completing the questionnaire. The questionnaire was easy for Chinese people to read and had no floor/ceiling effect (22, 23). In addition, the scale has been widely applied in some studies, such as in assessing the quality of life of patients with blood disorders and in the general population (15, 16). Thus, this study used this scale to assess the quality of life of patients with hyperuricemia and gout to investigate the applicability of the scale. Furthermore, since this investigation was based on the measurement of general health preferences of research subjects, it was able to generate health utility values to calculate pharmacoeconomics, and Quality-adjusted life years (QALYs) (24). Based on the literature (25), the method for calculating the health utility value in this study was the TTO method. Face-to-face interviews were conducted among the general population of multiple cities in China to collect basic demographic characteristics. The responses of the respondents were then modeled to obtain the coefficients at each dimension level. Meanwhile, researchers controlled the quality of the collected data. Complete health status was set at 1. The utility value of the health status was obtained by subtracting the coefficients of each dimension level calculated from 1, thereby allowing to estimate the utility value of the health status. The corresponding horizontal coefficients for each dimension can be obtained in the literature (25). The utility value in pharmacoeconomics usually ranges from 0 to 1, and sometimes it may be negative, representing a worse health condition than death. It can reflect the patient’s subjective satisfaction with their own health status, thereby helping doctors assess the patient’s health status better, make clinical decisions, and at the same time, it is conducive to optimizing the allocation of health resources.

The Chinese version of the SF-6Dv2 scale was used to compare patients with gout with hyperuricemia and healthy individuals. The SF-6Dv2 scale was developed based on the SF-6D scale. The SF-6Dv2 scale is divided into six dimensions, namely physical function, role limitation, social function, pain, mental health, and vitality. Each dimension is divided into 5 to 6 grades, with higher grades indicating more severe diseases. A total of 18,750 health status were described. The SF-6Dv2 marked the disease level of each dimension with numbers. The numbers of these six dimensions form a six-digit code representing a person’s health status. Each dimension was then divided into 5 to 6 grades, with higher grades indicating more severe diseases. A total of 18,750 health states were described. SF-6Dv2 marks the disease level of each dimension with numbers. The range of health utility values of the Chinese version of SF-6Dv2 was from −0.277 (the worst health status, having the digital code “555655”) to 1 (the best health status, with the digital code “111111”) (25).

All statistical analyses in this study were conducted using SPSS v.23.0 software. Non-parametric Mann–Whitney U Tests were used to analyze continuous variables, and chi-square tests were used to evaluate differences in the proportions of categorical variables. The educational level, sex, age, ethnicity, marital status, occupation, monthly income, medical insurance status, smoking history, drinking history and family history of chronic diseases of the two groups was evaluated using Fisher’s exact test. In this study, utility values were calculated using the integral utility system as described previously (25). The descriptive statistics were described by the proportion (%), average value, and standard deviation. All the p-values reported in this study were two-tailed and statistically significance was considered at p-values of <0.05.

The Cronbach’s alpha coefficient of this scale was 0.895, indicating good reliability. Meanwhile, a structural validity analysis was conducted on the scale. The KMO value of this scale was 0.882 (>0.6), and the significance was p < 0.001. This study consisted of six dimensions, namely physical function, vitality, mental health, role limitation, social function, and pain. The principal component analysis method was used and, based on the rotated component matrix, the load of each question in only one dimension was considered >0.5, that is, each question was valid and passed the validity test. Therefore, the validity of this questionnaire is relatively good.

Among patients with hyperuricemia, 8.77% (n = 15) reported a state of complete health (code “111111”), and no one reported a state of worst health (code “555655”). The vitality dimension accounted for the highest proportion (87.1%) among the responses with no questions in the report, followed by the pain at 86.5%, the physical function at 79.5%, the mental health at 78.9%, and finally the role limitation and the social function dimensions at 72.5 and 67.2%, respectively (see Figure 2A). The average utility value of the patient group was 0.621 (0.270). In the subgroup classification based on demographic characteristics (Table 2), there were statistically significant differences in utility values for age, marital status, educational attainment, occupation, whether staying up late, triglyceride level, severity of hyperuricemia and gout, preference for seafood, and duration of hyperuricemia and gout (p < 0.05). At the same time, from the Table 2, we found that older the age, married status, lower the educational level, retired workers, hypertriglyceridemia, not staying up late, severity of hyperuricemia and gout, preference for seafood, duration of hyperuricemia and gout ≥1 year; The utility value of patients in this year was even lower, being lower than that of other people in the same group.

In the control group, a total of 7.01% (n = 12) of the respondents reported complete health status (code “111111”), and none reported the worst health status (code “555655”). Among the control group, the role limitation dimension had the highest proportion of the responses reporting any problem (64.9%), followed by the vitality dimension (63.8%), mental health dimension (62%), physical function dimension (57.9%), social function dimension (50.3%), and finally the pain dimension (47.9%) (see Figure 2B). In terms of the pain dimension, one respondent reported the most severe level, which was the sixth level of the pain dimension, “very severe pain”. The average utility value of the control group was 0.803 (0.155), which was better than that of the gout group with hyperuricemia. Compared with the patient group, the control group reported significantly lower levels in the six dimensions of physical function, role limitation, social function, pain, mental health, and vitality (p < 0.05).

As shown in Table 2, with regard to demographic characteristics, the utility values of the subgroups of the disease group were lower than those of the control group. Among the two groups, the subgroups with the greatest differences were those over 50 years of age (0.247), those who did not stay up late (0.247), followed by the 40–49-year-old group (0.246), those with a smoking history (0.237), and married individuals (0.226). Meanwhile, in the subgroup comparison between the disease group and the control group, significant differences were observed in the utility values of the two groups in terms of age, educational background, smoking history, drinking history, and staying up late (p < 0.05).

Table 3 reports the results of the multiple linear regression analysis to identify factors associated with quality of life. We found that patients whose marital status was single and who did not like seafood were positively correlated with a health utility value. That is, the value of health utility of patients who were single and did not like seafood was significantly higher, the p-values were 0.032 and < 0.001, respectively. However, the health utility values of patients with hypertriglyceridemia, hyperuricemia, and moderate and severe gout severity were negatively correlated. That is, among patients with hyperuricemia, compared with patients with moderate-to-severe gout and hyper- triglyceridemia, the health utility values of patients with hyperuricemia and with a gout severity of mild and with normal triglyceride levels were significantly higher. Therefore, patients who are single, dislike seafood, have mild hyperuricemia and gout, and have normal triglyceride levels have a higher health utility value compared to those who are married, like seafood, have moderate to severe hyperuricemia and gout, and suffer from hypertriglyceridemia, a finding consistent with the conclusion drawn above.