Suboptimal health among Chinese middle school students may be associated with psychological symptoms and sleep duration: a cross-sectional survey in China

Abstract

Background

Suboptimal health status (SHS) is an intermediate status between ideal heath and illness, it is characterized by the perception of health complaints, general weakness, decreased immunity and low energy. An increasing number of Chinese middle school students are suffering from psychological symptoms (PS), particularly anxiety and depression. The relationship between SHS and PS is unclear in adolescents. This study aimed to investigate the prevalence of SHS and the correlation between SHS and PS among Chinese middle school students and to identify the SHS-related risk factors from the perspective of public health.

Methods

A cross-sectional study was conducted with the cluster sampling method among 1955 middle school students in Shantou, China. SHS was assessed by Suboptimal Health Status Questionnaire-25 (SHSQ-25). And the PS of anxiety and depression were assessed with Generalized Anxiety Disorder Scale (GAD-7) and Beck Depression Inventory-II Scale (BDI-II) self-assessment questionnaires. Variate logistic analysis was applied to explore risk factors of SHS. The relationship between SHS and PS among Chinese middle school students was subsequently analyzed.

Results

Among the 1955 participants, 1904 middle school students were finally included in the analysis, the effective response rate was 97.39%. The prevalence of SHS was 10.3% (197/1904) while the prevalence of anxiety and depression was 30.7% (585/1904) and 34.1% (649/1904), respectively. A strong correlation was identified between SHS and PS among middle school students. With the aggravation of anxiety and depression, the probability of suffering from SHS increased (both P<0.01). The scores for various dimensions of SHS among the depression and anxiety groups were higher compared to those of the non-depression and non-anxiety groups (all P<0.01 ). Multivariate regression showed that compared with sleeping less than six hours, 6–8 h is a protective factor for SHS (OR = 0.486, 95%CI = 0.278–0.851).

Conclusions

Attention should be given to SHS and PS in Chinese middle school students, as they are strongly associated. Lack of sleep is a risk factor for SHS, so sufficient sleep should be recommended to prevent it. Identifying additional risk factors and promoting adequate sleep will improve adolescent health.

Introduction

Adolescence is an important period of physical and mental growth. During this period, adolescents’ bodies develop rapidly, but their psychology is immature and unstable. In the past 30 years, China has undergone unprecedented economic development and social change. The change has led to tremendous transformation in disease epidemiology, and the main health burden among adolescents has shifted from infectious diseases and nutritional deficiencies to non-communicable diseases, especially mental health disorders [1]. Modern society has put forward higher requirements for adolescents, including mental wellness, self-control and adjustment abilities, social adaptability, and daily behavioral habits, etc. However, the mental health situation of Chinese adolescents is not optimistic, a significant number of adolescents have mental health disorders, and the proportion is rising [2–4]. And in China, adolescents regularly experience a variety of learning-related stressors including but not limited to long study hours, interpersonal relationships, emotional disturbance and parents’ expectations, which is particularly serious [5]. In China, both junior high school and high school students are collectively referred to as middle school students. Therefore, it is quite important to pay attention to the psychological and physical health of middle school students and the relationship between them.

The World Health Organization (WHO) points out that health is not merely no disease or physical weakness, but rather a dynamic state of well-being encompassing physiological, psychological, and social adaptation [6]. With the shift in biomedical models and the spectrum of human diseases, the intermediate state between illness and health is gradually being recognized, known as Suboptimal health status (SHS) [7]. Nowadays, SHS is recognized as a significant public health challenge globally [7]. SHS typically lacks clinical symptoms and signs or may involve symptomatic sensations without clinical evidence, but there is a potential predisposition to disease, and the body is in a state of reduced physiological function and psychological imbalance [8]. The characteristics of SHS are described as the perception of health complaints, general weakness, low energy and immunocompromised [9]. Previous studies have shown that the prevalence of SHS was 55.9% among college students and 74.2% among nurses in China [10, 11]. With the accelerating pace of life and increasing competitive pressures, adolescents inevitably experience varying degrees of psychological tension, fatigue, and significant psychological stress during their growth process [12]. Although these factors may not immediately lead to disease immediately, they may have the potential to impact the physical and mental health of adolescents, increasing the risk of SHS.

Previous studies have proved that SHS is associated with mental health disorders [11, 13, 14]. Although physical and psychological health of adolescents is receiving increasing attention, the psychological health status of Chinese adolescents is not optimistic. Recent epidemiological data suggested a significant number of Chinese adolescents exhibit symptoms of depression or anxiety [4, 15, 16]. Adolescent depression and anxiety not only affect their studies but also disrupt their regular lives. In severe cases, some may even engage in self-injuries or suicidal behaviors, causing huge economic losses and significant impacts on the normal societal development [17, 18].

The adolescent stage (ages 10 to 24) is a crucial period bridging childhood and adulthood. It is characterized by pubertal development, the evolution toward mature social roles, and the cultivation of independence. Adolescence represents a significant phase where individuals are highly influenced by peer groups and may adopt unhealthy behaviors like alcohol consumption, smoking, and poor dietary habits. These behaviors can impact both present and future health outcomes [19]. Unhealthy behaviors during adolescence are significantly harmful to the development of health consequences in later life [20]. Nevertheless, adolescence also presents a significant opportunity for shaping behavior positively, potentially leading to improved long-term health outcomes [19].

For middle school students, early identification of SHS and prevention from progressing to disease states is crucial. In view of this, this study aimed to examine the prevalence of SHS among Chinese middle school students, explore its correlation with PS, and identify SHS-related risk factors from a public health perspective to lay the foundation for further research and interventions.

Participants and methods

Inclusion criteria

The inclusion criteria were (1) According to the standards of WHO, the age range for adolescents is defined as 10 to 19 years, which is consistent with the inclusion criteria of the subjects in this study. (2) voluntarily participate in the survey, (3) no somatic diseases, (4) no psychiatric diseases or abnormalities currently, (5) no history of medication consumption in the previous 2 weeks.

Exclusion criteria

The exclusion criteria were (1) decline to participate in survey or refuse to provide informed consent, (2) unable to complete the questionnaire independently, (3) clinically diagnosed diseases.

Participants’ recruitment

A cross-sectional study was conducted at schools, Shantou city, China, from May to June 2022. The cluster random sampling method was used to select middle school students as the research subjects. Firstly, with the support of the education department, we gained the cooperation of two schools, one from an urban area and one from a rural area, both agreeing to allow us to conduct a pilot survey. These two schools have a total of 1,955 students. After excluding invalid questionnaires, the number of valid questionnaires was 1904 after review. The effective rate of the survey was 97.39% (1904/1955).

SHS, depression, and anxiety assessment

A general questionnaire was applied to investigate demographic information, including age, gender, height, weight, academic record, whether left behind, whether living on campus, average daily sleep time, exercise frequency, smoking behavior.

The condition of SHS was evaluated by the self-reporting questionnaire SHSQ-25. SHSQ-25 measures SHS across five dimensions: fatigue, cardiovascular system, digestive tract, immune system and mental state, comprising a total of 25 items [21]. Each item of SHSQ-25 adopts the Likert 5-point scoring method based on how often they underwent uncomfortable symptoms in the preceding 3 months, with the options “never or almost never,” “occasionally,” “often,” “very often,” and “always,” corresponding to 0, 1, 2, 3 and 4, respectively. The total score of SHSQ-25 was the sum of scores from each item, with a higher score indicating the worse health status [21]. Based on SHSQ-25, the health status was stratified into two classifications: ideal health (with summed score < 35) and suboptimal health (with summed score ≥ 35).

The severity of depression and anxiety of participants were assessed by the Beck Depression Inventory-II (BDI-II) and Generalized Anxiety Disorder Scale (GAD-7) respectively [22, 23]. BDI-II comprises 21 items, based on the criteria provided by the scale and summed score, the participants were stratified into four classifications: no depression symptom (≤ 13), mild depression (14–19), moderate depression (20–28), and severe depression (≥ 29) [22]. The GAD-7 was utilized to investigate the degree of anxiety symptom. The GAD-7 consists of 7 items, with each item offering four response options: “not at all,” “several days,” “more than a week,” and “nearly every day,” corresponding to scores of 0, 1, 2, and 3, respectively. The higher the score, the more severe the anxiety symptom. Based on the criteria provided by the scale and summed score, the participants were categorized into the following groups: normal (0–4), mild anxiety (5–9), and severe anxiety (≥ 10).

Grouping and statistical analysis

The statistical analysis was performed by SPSS (version 23.0, IBM, New York, USA). Quantitative data normally distributed were described by the mean and standard deviation (mean ± SD) while non-normally distributed data were described as quartiles (P25 ~ P75). Qualitative data were described by percentage or ratio. Student’s t (t) test, Pearson chi-squared (χ²) test, Wilcoxon rank sum (z) test, ANOVA (F) test and LSD test were used to compare differences between groups. Multivariate logistic regression analysis was used to exploring risk factors for SHS, by which odds ratio (OR) and 95% confidence intervals (CI) were obtained. P < 0.05 was considered statistically significant.

For comparison of GAD-7 and BDI-II scores, participants were divided by quartile method based on shsq-25 scores into 4 groups as follows: Group (A) SHSQ-25 score ≤ 7, Group (B) SHSQ-25 score 8–14, Group (C) SHSQ-25 score 15–22, Group (D) SHSQ-25 score ≥ 23.

Results

Characteristics of participants

The characteristics of 1904 eligible students participated in the survey as shown in Table 1. Among 1904 students, 10.3% (197/1904) had SHS. By comparing two groups, there were statistically significant difference on age (P<0.001), gender (P = 0.004), average daily sleep time (P<0.001), smoking status (P<0.001), drinking behavior (P<0.001), and exercise frequency (P<0.001).

Table 1.

Characteristics of participants

Variables	n	OPH n = 1707 (89.7%)		SHS n = 197 (10.3%)		χ2	P
Age (years)* *					17.031		<0.001
12–14	679	635 (93.5)	44 (6.5)
15–17	1148	1005 (87.5)	143 (12.5)
≥ 18	77	67 (87.0)	10 (13.0)
Gender*
Male	978	896 (91.6)	82 (8.4)		8.347		0.004
Female	926	811 (87.6)	115 (12.4)
BMI					2.323		0.508
Thin	898	810 (90.2)	88 (9.8)
Normal	770	692 (89.9)	78 (10.1)
Overweight	112	97 (86.6)	15 (13.4)
Obese	124	108 (87.1)	16 (12.9)
Academic record					8.866		0.065
<10%	294	272 (92.5)	22 (7.5)
10-30%	450	412 (91.6)	38 (8.4)
30-50%	561	489 (87.2)	72 (12.8)
50-70%	385	346 (89.9)	39 (10.1)
>70%	214	188 (87.9)	26 (12.1)
Left-behind children					0.125		0.724
Yes	78	69 (88.5)	9 (11.5)
No	1826	1638 (89.7)	188 (10.3)
Live in campus					2.155		0.142
Yes	220	191 (86.8)	29 (13.2)
No	1684	1516 (90.0)	168 (10.0)
Average daily sleep time**					107.861		<0.001
<6 h	195	133 (68.2)	62 (31.8)
6–8 h	1501	1381 (92.0)	120 (8.0)
>8 h	208	193 (92.8)	15 (7.2)
Smoking status**					37.673		<0.001
Yes	177	135 (76.3)	42 (23.7)
No	1727	1572 (91.0)	155 (9.0)
Drinking behavior**					82.803		<0.001
Yes	70	40 (57.1)	30 (42.9)
No	1834	1667 (90.9)	167 (9.1)
Exercise frequency**					73.125		<0.001
Seldom or never	125	84 (67.2)	41 (32.8)
Occasionally	1244	1131 (90.9)	113 (9.1)
Frequently	535	492 (92.0)	43 (8.0)

^{*P<0.05, ** P<0.001}

Psychological states of participants

As shown in Table 2, SHS middle school students had statistically higher mean GAD-7 score (11.53 versus 2.60, P<0.001) and BDI-II (30.91 versus 9.11, P<0.001) compared with OPH middle school students. And as the levels of anxiety and depression symptoms intensify, the rate of SHS increased.

Table 2.

Comparison of mean scores of GAD-7 and BDI-II, and degree of symptoms between OPH and SHS groups

Variables	n	OPH n = 1707 (89.7%)		SHS n = 197 (10.3%)		t/z	P
GAD-7	1904	2.60 ± 3.10	11.53 ± 5.60		-34.484		<0.001
Normal	1319	1301 (76.2)	18 (9.1)		488.940		<0.001
Mild	424	356 (20.9)	68 (34.5)
Severe	161	50 (2.9)	111 (56.4)
BDI-II	1904	9.11 ± 9.49	30.91 ± 12.39		-29.481		<0.001
Normal	1255	1238 (72.5)	17 (8.6)		454.443		<0.001
Mild	240	220 (12.9)	20 (10.2)
Moderate	210	170 (10.0)	40 (20.3)
Severe	199	79 (14.6)	120 (60.9)

Logistic regression analysis on SHS

To ensure the stability of multivariate model and avoid overfitting, we only included variables with statistical significance (P<0.05) from the univariate analysis in the multivariate model. As shown in Table 3, the multivariate regression analysis with whether had SHS as the dependent variable was performed to identify major influences showed that average sleep time (P = 0.017), GAD-7 (P<0.001) and BDI-II (P<0.001) were positively associated with SHS. Compared with sleeping less than six hours, 6–8 h is a protective factor for SHS (OR = 0.486, 95%CI = 0.278–0.851). As the score of GAD-7 and BDI-II increased, adolescents were 1.327 times and 1.082 times increased risk of developing SHS, respectively.

Table 3.

Multivariate logistic regression analysis for SHS

	Β	SE		Wald		P	Exp(B) 95% CI
Male	-0.227	0.239	0.904		0.191			0.797 (0.499–1.273)
Age			3.326		0.190
15–17	0.429	0.263	2.663		0.103			1.535 (0.917–2.569)
>18	0.695	0.531	1.713		0.191			2.003 (0.708–5.668)
Average sleep time			8.146		0.017
6–8 h	-0.721	0.285	6.376		0.012			0.486 (0.278–0.851)
>8 h	-0.067	0.456	0.021		0.884			0.936 (0.383–2.288)
Smoking	-0.002	0.417	0.000		0.996			0.998 (0.440–2.262)
Drinking	0.549	0.514	1.140		0.286			1.731 (0.632–4.742)
Exercise			1.664		0.435
Seldom or never	0.045	0.422	0.012		0.914			1.046 (0.458–2.392)
Occasionally	-0.288	0.280	1.052		0.305			0.750 (0.433–1.299)
GAD-7	0.283	0.029	92.061		<0.001			1.327 (1.252–1.406)
BDI-II	0.079	0.011	51.003		<0.001			1.082 (1.059–1.106)

Correlation between PS and SHS

Among the students participated in the survey, there were statistically differences in the average GAD-7 and BDI-II scores between all four quartiles of the SHS scores (all P<0.001), and the score of GAD-7 and BDI-II increased significantly with increasing SHS quartile scores (Table 4).

Table 4.

Comparison of GAD-7 and BDI-II scores of adolescents grouped by SHSQ-25 quartile

	Group A (n = 487)	Group B (n = 470)	Group C (n = 479)	Group D (n = 468)	F	P	LSD
GAD-7	0.69 ± 1.62	1.95 ± 2.43	3.45 ± 2.77	8.13 ± 5.45	440.270	<0.001	A vs. B** A vs. C** A vs. D** B vs. C** B vs. D** C vs. D**
BDI-II	3.00 ± 5.03	8.09 ± 8.44	11.26 ± 9.02	23.45 ± 12.73	424.488	<0.001	A vs. B** A vs. C** A vs. D** B vs. C** B vs. D** C vs. D**

^{** P<0.001}

Compared with non-anxiety group, the average SHS specific domains scores of mental health status, immune system, digestive tract, cardiovascular health and fatigue were statistically significantly increased among the students who had anxiety symptom (Table 5). Similarly, the depression group scored higher in each dimension of SHS than non-depression group (Table 6).

Table 5.

Comparison of the scores of the five domains of SHSQ-25 between the non-anxiety and anxiety groups depending on GAD-7 scores

	non-anxiety n = 1319 (69.28%)	anxiety n = 585 (30.72%)	t	P
Mental state	3.83 ± 3.51	10.00 ± 5.80	-28.609	<0.001
Immune system	3.83 ± 3.51	10.00 ± 5.80	-17.219	<0.001
Digestive tract	1.07 ± 1.53	2.75 ± 2.24	-19.021	<0.001
Cardiovascular system	0.43 ± 0.95	1.95 ± 2.31	-20.358	<0.001
Fatigue	5.24 ± 3.57	11.48 ± 5.95	-28.221	<0.001
Total score	11.91 ± 8.58	28.83 ± 15.28	-30.738	<0.001

Table 6.

Comparison of the scores of the five domains of SHSQ-25 between the non-depression and depression groups depending on BDI-II scores

	non-depression n = 1255 (65.91%)	depression n = 649 (34.09%)	t	P
Mental status	3.73 ± 3.52	9.58 ± 5.70	-27.528	<0.001
Immune system	1.35 ± 1.35	2.49 ± 2.03	-14.575	<0.001
Digestive tract	1.01 ± 1.40	2.71 ± 2.30	-20.031	<0.001
Cardiovascular system	0.41 ± 0.96	1.84 ± 2.22	-19.452	<0.001
Fatigue	5.14 ± 3.51	11.04 ± 5.93	-27.207	<0.001
Total score	11.66 ± 8.54	27.66 ± 15.13	-29.465	<0.001

Correlation between sleep and SHS

As shown in Table 7, the average daily sleep time of students had a significant inverse association with SHS score. There were statistical differences between the total SHS score and score of each domain among three groups categorized by average daily sleep time (all P<0.001), and differences existed between each group. Specifically, with a decrease in sleep time, the score of each domain of SHS increased significantly.

Table 7.

Comparison of the scores of the five domains of SHSQ-25 between the groups depending on average daily sleep time

	Group 1 n = 195 (10.24%)	Group 2 n = 1501 (78.83%)	Group 3 n = 208 (10.92%)	F	P	LSD
Mental status	8.78 ± 6.62	5.54 ± 4.85	4.24 ± 5.02	45.253	<0.001	A vs. B** A vs. C** B vs. C*
Immune system	2.46 ± 2.45	1.70 ± 1.61	1.31 ± 1.21	25.081	<0.001	A vs. B** A vs. C** B vs. C*
Digestive tract	2.83 ± 2.99	1.49 ± 1.71	1.13 ± 1.82	49.937	<0.001	A vs. B** A vs. C** B vs. C*
Cardiovascular system	1.55 ± 2.56	0.88 ± 1.56	0.41 ± 0.91	25.236	<0.001	A vs. B** A vs. C** B vs. C**
Fatigue	10.99 ± 7.23	6.94 ± 4.82	5.13 ± 4.63	73.038	<0.001	A vs. B** A vs. C** B vs. C**
Total score	26.62 ± 19.00	16.55 ± 12.35	12.22 ± 11.55	67.133	<0.001	A vs. B** A vs. C** B vs. C**

^{Group (1) <6 h, Group (2) 6–8 h, Group (3) >8 h, * P<0.05, ** P<0.001}

Discussion

The WHO defined health as the state of complete physical, mental, and social well-being, and not merely the absence of disease or infirmity [6]. SHS may not always correspond to either the early stage or preclinical phase of an illness, but it is typically defined as the period preceding the onset of clinical manifestations of diseases. Individuals in the early stage or preclinical period often require interventions with specific therapies aimed at preventing or delaying the onset of the disease [24]. Modifiable risk factors, in particular, play a crucial role in implementing targeted, cost-effective prevention measures for illnesses in the population. Adolescence is a critical period of physical, psychological and social adaptation. However, China’s environmental pollution and rapid changes in lifestyle have widely affected people’s health conditions and greatly increased the risk of SHS [25]. At the same time, SHS is also a major challenge faced by the global public health [26, 27]. With the rapid development of the social economy, various cultures, pressures, values, lifestyle behaviors, etc., swiftly infiltrate the adolescents, significantly impacting the immature physical and mental aspects [28–30]. The research findings revealed that among 1904 middle school students, a total of 197 (10.35%) were identified SHS. Previous research on people aged 15–60 in China showed that the prevalence of SHS was 46.3%, which was higher than current study [31]. And the research conducted in Chinese universities showed the prevalence of SHS among college students was 21.0%, which was also higher than current study [14]. The SHS rate among adolescents was slightly lower compared to the general population, which may be attributed to the fact that SHS tends to increase with age [11]. However, this by no means implies that SHS in adolescents should be overlooked. Instead, we should pay more attention to SHS in adolescents. Adolescents develop rapidly physically and mentally but are immature, while simultaneously facing a series of external pressures such as academic, employment, and emotional challenges, leading to a gradual prevalence of SHS [32]. SHS may be a pathway to a whole lifespan, determining the increased cause of health risk in old age and it is recognized that early diagnosis and timely management can prevent the occurrence of SHS [33].

Adolescents with SHS often manifests in daily life as low energy and a state of fatigue, severely impacting the academic performance and healthy growth of adolescents [7]. At the same time, SHS is associated with internalizing issues such as anxiety and depression [11], consistent with the results obtained in this study focusing on the middle school students. In the present study, the prevalence of depressive symptoms and anxiety symptoms are 34.09% and 30.72%, respectively, which is consistent with those reported by other studies [34, 35]. The PS of Chinese adolescents is not optimistic. The present study showed that compared with students without PS, the prevalence of SHS among students with depression and anxiety symptoms were 91.4% and 90.9%, respectively (Table 2), which were extremely high. And through multivariate logistic regression, it was found that as the scores of GAD-7 and BDI-II increased, adolescents were 1.33 times and 1.08 times increased risk of developing SHS, respectively (Table 3). Another finding was that as the SHS score increased, both the GAD-7 and BDI-II scores increased in the same direction (Table 4). In addition, the five domain scores and total score of SHS were significantly higher in the groups of students who had anxiety or depression symptom (Tables 5 and 6). According to the results of this study, a strong correlation can be identified between PS and SHS. The reasons for adolescents’ susceptibility to psychological issues such as depression or anxiety are complex and involve multiple factors. Firstly, physiological changes are a significant characteristic of adolescence, and these changes during this period may have a significant impact on emotional and PS. The hormonal levels fluctuate during adolescence, with an increase in the secretion of sex hormones and growth hormones promoting rapid physical growth and development, the hormonal fluctuation may lead to emotional swings [36, 37]. In addition, heavy academic pressure is a significant challenge faced by adolescents, especially in middle school stage, which may have a huge impact on the psychological well-being of Chinese adolescents [38, 39]. Adolescents need to cope with numerous exams and academic assessments, such as high school or university entrance exams, which are extremely crucial in China and are likely result in anxiety and depression among adolescents. Meanwhile, these intense competitions mean that students must perform better academically for better prospects. This kind of competition often adds a considerable amount of anxiety and pressure to them. Furthermore, middle school students may feel overwhelmed by academic burdens, including a substantial amount of homework and extracurricular tutoring, leaving them with insufficient time for physical and mental rest. Faced with these pressures, students may experience feelings of frustration, anxiety, and even depression [40]. Psychological stress is a type of negative emotional state that, in the long term, may lead to SHS due to altered profiling of serum cortisol levels and glucocorticoid receptor activity [41, 42]. Adolescents may also experience PS due to the excessive expectations from parents [43]. The intense competitions, academic burdens, physiological changes and excessive expectations affect the physical and mental health of adolescents in China, resulting in poor health status. For example, if the symptoms of depression and anxiety are not well managed, they will increase the risk of suffering cardiovascular diseases [44, 45].

In the OPH group, the proportion of sleep time less than 6 h was lower than that of SHS group. The results of multivariate logistic regression analysis with whether had SHS as the dependent variable also showed that compared with students sleep less than 6 h, sleeping 6–8 h is a significant protective factor (P = 0.012) for SHS (Table 3). In addition, with the increase in sleeping time, the scores of each dimension of SHS decreased (Table 7). The explanation to the observed finding may owe to the shared common characteristics between SHS and insufficient sleep, particularly the relevant items in the questionnaires and the common predisposing factors associated with their causes. These results indicate that adequate sleeping time helps reduce the risk of SHS. Previous studies have indicated that sufficient sleep contributes to reducing psychological stress and helps maintain both physical and mental well-being [46, 47]. Sleep is an important factor in promoting physical growth and development in adolescents and helps the maintenance of normal bodily functions [47]. Moreover, numerous studies have proven that sufficient sleep helps strengthen the immune system, enabling adolescents more resistant to disease [48], and the regular sleep pattern contributes to maintaining normal metabolic functions, preventing obesity, and other metabolic issues [49, 50]. This, in turn, helps adolescents better cope with the pressures and challenges of daily life. For middle school students, adequate sleep is crucial for learning, memory and attention [51]. It helps enhance learning efficiency and academic performance.

This research has confirmed a significant correlation between SHS and anxiety, depression among middle school students, with inadequate sleep of less than 6 h being identified as a predictive factor for SHS. From the perspective of public health, identifying modifiable risk factors, predicting, preventing and performing early personalized interventions are highly important for preventing and reducing the risk of disease. For middle school students, physical health is just as important as mental health. SHSQ-25 can be used to screen for SHS groups, and combined with physical examination indicators, personalized interventions can be implemented in future work to extend life expectancy.

Limitations

The cross-sectional study data were derived from self-administered questionnaires. Students surveyed need to recall information about themselves, which may lead to recall bias. Additionally, regarding certain sensitive questions, there was a possibility of exaggeration or concealment, resulting in socially desirable responses and causing reporting bias. In addition, the study was a cross-sectional study, making it difficult to infer a casual relationship between PS and SHS, further longitudinal studies were needed to infer causal relationships between variables.

Conclusions

The prevalence of SHS and PS among middle school students in China are relatively high. The study demonstrated that that adolescents experiencing anxiety, depression, and insufficient sleep are more prone to SHS. From the perspectives of public health, strategies for early, personalised intervention at the SHS stage are urgently needed to improve the mental health of adolescents and enhance their coping and adaptability skills. The sleep condition is also worth noting, and it is essential to ensure that adolescents obtain sufficient sleep.

Overall, the SHS among middle school students shows a worrying trend, significantly compromising their normal healthy development and impacting the comprehensive enhancement of their life. Although SHS is not a disease, it still has an important negative impact on adolescents. Therefore, it is crucial to prioritize and take measures to prevent SHS among adolescents. To prevent the occurrence of SHS among adolescents, comprehensive measures need to be implemented. These measures encompass not only developing good sleeping habits to ensure sufficient sleep, but also enhancing social and emotional support, improving dietary habits, increasing physical activity, and elevating the overall health level of adolescents. Parents, schools, and society also need to provide more attention and support to adolescents. The health department should take the lead in collaboration with education, civil affairs, and other relevant departments to guide adolescents and their guardians in forming a health management mindset. Simultaneously, emphasis should be placed on the collaboration between families and schools, with widespread participation from both, ensuring quality outdoor activities while implementing educational measures to reduce stress. Prioritizing health care and regular check-ups, promoting balanced nutrition, and comprehensive prevention strategies are crucial for addressing SHS among adolescents.

Abbreviations

SHS

Suboptimal health status

OPH

Optimal health

PS

Psychological symptoms

WHO

World Health Organization

BMI

Body mass index

SHSQ-25

Suboptimal Health Status Questionnaire-25

BDI-II

Beck Depression Inventory-II

GAD-7

Generalized Anxiety Disorder Scale

OR

Odds ratio

CI

Confidence intervals

Author contributions

Z.Z. and C.S. undertook the data analysis, wrote down the research process and literature reviews, and interpreted the results. Z.X. and C.H. performed the data collection, complete statistical tables, and result analysis. L.L. was in charge of the conception, undertook the design of the study framework, took responsibility for the integrity of the data and the accuracy of the data, and interpreted the conclusion.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Data availability

The datasets and materials used and analyzed in the study are available from the corresponding author on reasonable request.

Declarations

Consent for publication

Not Applicable.

Competing interests

The authors declare no competing interests.

Ethics approval and consent to participant

This study was approved by the Ethics Committee of Shantou University Medical School (No. SUMC-2022-076) and we had also obtained the consent of participants and their parents or legal guardians. Before filling out the questionnaire, participants voluntarily signed an informed consent form.