SUBMITTED 13 AUG 22 1 REVISION REQ. 21 SEP 22; REVISION RECD. 24 OCT 22 2 ACCEPTED 9 NOV 22 3 ONLINE-FIRST: DECEMBER 2022 4 DOI: https://doi.org/10.18295/squmj.12.2022.067 5 6 Examination of Behavioural Patterns of Psychological Distress and 7 Evaluation of Related Factors 8 A latent class regression 9 Negar Sangsefidi,1 *Jamshid Jamali,1 Zahra Rahimi,1 Ana Kazemi2 10 11 1Department of Biostatistics, School of Health, Mashhad University of Medical Sciences, 12 Mashhad, Iran; 2Department of Psychology, Faculty of Psychology and Educational Sciences, 13 Kerman Branch, Islamic Azad University, Kerman, Iran. 14 *Corresponding Author’s e-mail: jamalij@mums.ac.ir 15 16 Abstract 17 Objectives: Psychological Distress (PD) is a unique and suffering emotional state in response to 18 a stressor or specific need that leads to temporary or permanent impacts. Due to its negative 19 effects on several features of life like the quality of life, health, performance, and productivity of 20 individuals, PD and its consequences are considered as a public health priority. In this study, we 21 aim to identify the behavioral pattern of PD in the population of 18 to 65 years old in Mashhad 22 using latent class regression and evaluate the related factors. Methods: A cross-sectional study 23 was performed on 425286 individuals aged 18 to 65, who were referred to health centers in 24 Mashhad, northeastern Iran in the first half of 2018. The information required for this study 25 including a checklist of demographic information and the Six Item Kessler Psychological 26 Distress Scale (k-6) was obtained from the Sina system. Results: Latent class regression 27 identified three latent patterns of PD in answering the questions of the K-6 questionnaire, 28 including severe PD (14%), low PD distress (40%), and no PD (46%). Statistical variables of this 29 study due to the results are considered as the following; women, illiterate people, unemployed 30 and divorced people, individuals aged between 50-59 years old, and people with low weight 31 were more likely to be in severe PD class than no PD class. Conclusion: Although a small 32 percentage of people were classified as severely disturbed, the findings showed a high rate of 33 symptoms of distress and sadness even in the no PD class. 34 Keywords: Cross-Sectional Studies, Psychological Distress, Latent Class Analysis, Iran 35 36 Advances in Knowledge 37  Psychological Distress (PD) is a unique and suffering emotional state in response to a 38 stressor or specific need that leads to temporary or permanent impacts. PD adverse effects 39 on health, performance, and productivity are proposed as a public health priority. 40 41 Application to Patient Care 42  There is a high rate of symptoms of significant distress and sadness even in the no PD 43 class. 44  There is a need to develop appropriate strategies for prevention and treatment and 45 provide the necessary training and intervention for high-risk groups of PD, especially 46 women. 47  Using the achieved results through careful planning, diagnosis, treatment, and prevention 48 of mental disease can lead to building a healthy and vibrant society away from mental 49 and psychosomatic illnesses. 50 51 Introduction 52 Tensions, stresses and life's problems are common phenomena of modern life, but ineffective 53 management of these challenges can lead to stress disorders, Psychological Distress (PD), and 54 physical ailments. According to numerous epidemiological studies in recent years, the 55 prevalence of mental disorders in different countries is increasing daily; The prevalence of these 56 disorders in different countries varies from 13 to 22 %.1 These disorders are one of the five 57 leading causes of disability and are known as an strong predictor of death from heart disease, 58 stroke, and cancer.1 It is estimated that 12% of the total burden of disease globally is due to 59 mental disorders and is expected to increase to 15% by 2020.2 The prevalence of these disorders 60 in Iran is estimated between 11.9% to 23.8%.3, 4 61 62 PD as considered by Mirowsky. J. is a state of emotional suffering consisting of symptoms 63 related to depression and anxiety,5 which lead to decline in quality of life at the individual level 64 and because of their adverse effects on health, performance, and productivity, are proposed as a 65 public health priority.1 It is noticeable to mention some symptoms of PD that include a wide 66 range of physical to mental states. Sleep disturbance, anorexia, chronic pain, fatigue, loss of 67 menstruation for women and headaches are some of Physical symptoms while some symptoms 68 like feeling of sadness, Nervous, Helplessness, Hopelessness and Worthlessness are known as 69 mental ones. The prevalence of mild mental disorders (depression, anxiety) in different countries 70 in general populations varies between 7.3 to 52.5%.6 According to DSM-5-TR high levels of PD 71 is considered as one of negative functional consequences of Specific learning disorder.7 72 73 According to the results of the Global Burden of Disease Study (GBD) in 2016, depressive and 74 anxiety disorders from 2005 to 2016 were among the top ten causes of loss of Iranians life due to 75 disability.8 The study estimated the number of people with mental illnesses and drug-related 76 disorders in 2016 at 1.1 billion worldwide.8 The term PD is a type of mental symptoms that is 77 used as an indicator of mental health issues in demographic and epidemiological studies.9 78 79 PD and its measurements strongly refer to the symptoms of depression and anxiety and mainly 80 refer to cognitive behaviors disorders, Depressive Disorders and Anxiety Disorders so reports 81 indicate that PD affected most of these disorders.10 As mentioned, PD is commonly referred to as 82 emotional suffering characterized by symptoms of depression (such as apathy, sadness, 83 hopelessness) and anxiety (such as restlessness, feeling tense).9 In other words, PD is used to 84 describe a short but acute period of a specific mental symptoms that first presents with features 85 of depression or anxiety and can be deemed as a type of abnormality that is responsible for 86 maladaptive cognitive behavior and thought, which requires specialized intervention.11 PD 87 encompasses a much wider range of experiences than mental illness, ranging from mild 88 symptoms to severe psychiatric disease.12 In these cases, it is noticeable that life enthusiasm 89 notably decreases, and also feeling of heartbreak and despair become dominant throughout an 90 individual's life.11 So severe PD is a predictor of serious mental illnesses like depression and 91 anxiety and other disorders.2 92 https://en.wikipedia.org/wiki/Anorexia_(symptom) https://en.wikipedia.org/wiki/Chronic_pain https://en.wikipedia.org/wiki/Fatigue_(medical) https://en.wikipedia.org/wiki/Headache https://apps.who.int/iris/bitstream/handle/10665/41864/0965546608_eng.pdf 93 Based on the findings of previous studies, the prevalence of PD in India was estimated at 20.2%, 94 in Japan at 6.7%, in the United States at 3.4%, in Canada at 12%, and in Australia at 11.1%.2, 13-95 15 96 97 The prevalence of PD in Iran is reported to be very diverse, from 10.1% to 57.2%, depending on 98 the questionnaire used, the cut-off point considered, the demographic characteristics and the time 99 of the study.16-20 100 101 Studies in different parts of Iran also show that the prevalence of PD is not only less than the 102 recorded statistics of other countries but also not less than the reports of the World Health 103 Organization and the reported by Noorbala study in Mashhad and Shafiei in Isfahan.21, 22 104 105 Three categories of factors include Socio-demographic characteristics (e.g., gender, age, and 106 ethnicity), Factors related to stress (e.g., living conditions and life events), and Personal 107 resources (e.g., income, education, social network, and social support) are recognized as 108 influential factors in PD in the general population.2, 9, 23-25 109 110 Recent studies conducted in different parts of the world showed a high prevalence of PD due to 111 increasing rate of mental disorders like anxiety and depression ones. Such a trend has created the 112 need for appropriate health care and services to provide mental health services in health centers, 113 especially for high-risk groups of mental disorders. For this purpose, epidemiological studies of 114 PD play an important role in determining the general mental health status of the community, 115 identifying related demographic factors, and estimating the resources needed to provide better 116 health services in the country. Health care centers can also play a critical role in different 117 processes such as diagnosis, care, and treatment of individuals grouped in high-risk mental 118 disorders. There are several fields of study such as the patterns of PD and the evaluation of 119 related factors simultaneously in a large-scale study, which has been less studied especially in 120 Iran. Therefore, this study intends to examine the pattern of PD of patients aged 18 to 65 years in 121 Mashhad health centers based on the K-6 questionnaire. The research identifies related factors, 122 provides appropriate suggestions and programs in order to provide better mental health services 123 for people prone to psychological disorders, and also helps the relevant authorities. 124 125 Methods 126 The present study is cross-sectional and descriptive-analytical research was performed in 127 Mashhad. Mashhad is the second-most-populous city in Iran and the capital of Razavi Khorasan 128 Province, which is located in the northeast of the country. The information used in this study was 129 extracted from the Sina Electronic Health Record System (SinaEHR) database under the 130 supervision of Mashhad University of Medical Sciences. Sina system has been used since 2016 131 to electronically record the health records of patients who were referred to health centers in 132 Khorasan Razavi province and so far covers about 40% of the population of Mashhad. This 133 system includes demographic information, health records of each individual, reports of 134 physicians and health care providers, laboratory results, screening forms and age group care, and 135 other details of clients' files. One of the screening forms used in this system is the K-6 136 questionnaire. In this study, information was received on people aged 18-65 who were referred to 137 Mashhad health centers for the first time in the first half of 2018 and completed the K-6 138 questionnaire. The inclusion criterion in this study was the answer to at least 50% of questions 139 of the questionnaire (3 questions), and people who had a diagnosis of neurological problems in 140 the past were excluded from the study. Data after correction and purification included 425286 141 people. 142 143 Voluntary referral, the confidentiality of identity information, non-disclosure of individuals' 144 names, lack of prejudice, and involvement of inclinations in the research results, and mentioning 145 of all scientific sources have been among the ethical considerations considered in this research. 146 This study has been approved by the National Committee of Ethics in Biomedical Research with 147 the ethics ID: IR.MUMS.REC.1398.058. 148 149 This survey comprised two instruments to gather data: standard demographic questions including 150 gender, age, marital status, level of education, job type, place of residence, body mass index, and 151 six-item Kessler psychological distress scale (K-6) to measure the participants’ PD. The K6 scale 152 is a population-based screening measure for identifying PD and is widely used in general 153 populations.23, 26-28 This scale is a truncated version of 6 items from the K10 scale that was 154 introduced in 2002 by Kessler et al. 8 Responses were scored on a five-point Likert scale 155 reflecting how much over the past month time respondents had experienced 6 symptoms, 156 including sadness, restless, nervous, helpless, hopeless, and worthless. The measure has five 157 response categories ranging from 0 (none of the time) to 4 (all of the time). The items were 158 summed to generate a total score ranging from 0 to 24, with higher scores indicating higher 159 levels of PD.10 The validity and reliability of its Persian version have also been confirmed in 160 previous studies.10, 18, 29 161 162 Latent Class Regression (LCR), a model-based clustering approach, was used to classify each 163 participant into a latent class whose members report similar patterns of responses K-6 164 questionnaire. Determining the cut-off point for the PD questionnaire is challenging, and several 165 cut-off points have been proposed so far. 9, 15, 23 In LCR, there is no need for a cut-off point that 166 is a function of demographic characteristics of communities. 167 168 LCR can also assess the effect of covariates on the classification.30, 31 Huang suggested a 169 generalization of LCR can evaluate the effect of covariates on latent variables as well as the 170 observed variables.32 Interpretation of coefficients in LCR is similar to logistic regression based 171 on odds ratio. Determining the optimal number of latent classes in LCR is challenging.33, 34 172 Statistical criteria (such as Akaike Information Criterion, Bayesian Information Criterion, 173 likelihood-based tests, log-likelihood difference test, Lo-Mendell-Rubin test, bootstrap 174 likelihood ratio test, and entropy) and interpretability are commonly used to determine the 175 number of classes.33 176 177 Models with lower evaluation criteria (AIC, BIC, AIC3, and CAIC) are preferred to those with 178 higher values for these criteria. Other fit statistics such as likelihood tests (i.e., tests log-179 likelihood difference test, Lo-Mendell-Rubin test, and the bootstrapped likelihood ratio test) 180 provide a p-value, which indicates if one model is statistically better than another.34 Another set 181 of methods for evaluating LC cluster models is based on the uncertainty of classification or, 182 equivalently, the separation of the clusters. Entropy as a diagnostic statistic, indicates how 183 accurately the model defines classes. In general, an entropy value close to 1 is ideal and above .8 184 is acceptable.35 185 186 In this study, K-6 questions are considered as indicator variables, the PD is known as a latent 187 variable, and gender, age, marital status, education level, job type, residence, body mass index 188 are covariates in LCR. All analyses were performed using LatentGold 5. If the p-value was less 189 than 0.05 (typically ≤ 0.05), the result was considered significant. 190 191 Results 192 Out of 425286 participants, 72.7% were women, 90.6% were married, 72.5% had a diploma and 193 undergraduate education, and 54.2% were suburban residents. The mean age and body mass 194 index (BMI) of the participants were 36.02±9.58 years and 26.5±4.88, respectively. 195 Demographic characteristics of the study population are presented in Table 1. 196 197 The mean score of the K-6 questionnaire is 4.23±4.54. Most people (over 75%) have 198 experienced little or no symptoms of anxiety. However, half of the people have always, 199 sometimes or most of the time been upset and sad. Only 3% of people always or most often 200 suffered from feelings of emptiness and worthlessness. This rate was less than 5% for symptoms 201 of hopelessness and helplessness. It is worth mentioning that the rate of answering the questions 202 of the questionnaire is 98.5%. 203 204 To determine the optimal number of latent classes, goodness-of-fit criteria for the LCR model 205 with 2-6 latent classes fitted to the data, and the results are shown in Table 2. As the number of 206 classes increased, the goodness-of-fit indices decreased, but for models with more than three 207 classes, no significant improvement in index values was observed. The value of entropy and R2 208 in the latent class model with three classes are 0.78 and 0.79, respectively, which is a statistically 209 significant value for a model and can well explain the latent pattern of the data. This model also 210 can interpret in practice. Considering more than three classes makes it difficult to interpret the 211 data correctly. As a result, the latent class model with three classes is the optimal model for the 212 studying data. 213 214 The proportions of individuals in the classes that have been created based on the K-6 question 215 pattern are presented in Table 3. 216 217 It can be seen that no PD class, which has the highest volume among the classes, people did not 218 report any PD symptoms during one month. In other words, more than 90% of these people have 219 never experienced symptoms of PD. In the low PD class, at least 80% of people have never or 220 minor experienced symptoms of nervous, helplessness, hopelessness, or worthlessness. 221 Nevertheless, this rate was higher for the symptoms of sadness and restlessness; over a month, 222 more than 60% of people reported these symptoms slightly or occasionally. This class accounts 223 for 39% of the samples. It was estimated that 14% of people are suffered from severe PD. Most 224 people in this class sometimes suffer from symptoms of PD. But, most of the time, they felt 225 sadness and restlessness. 226 227 The LCR model, in addition to determining the latent classes, also makes it possible to evaluate 228 the effect of independent variables on the placement of individuals in the formed latent classes. 229 In this study, the no PD class is considered as a reference category. The numerical value of the 230 coefficients (in terms of odds ratio) expresses the effect of increasing one unit in the independent 231 variable on the placement of individuals in classes of severe and low PD compared to no PD. 232 233 Table 4 shows the effect of independent variables on the membership of individuals in PD 234 classes compared to the reference class in the form of regression coefficients. 235 236 The findings of Huang's LCR model showed that most of the auxiliary variables have a 237 significant relationship with patterns of PD. 238 239 So that women, divorced, illiterate, unemployed, aged 50-59 years and underweight people have 240 a higher chance among other people to be in the class of severe PD. 241 242 In the LCR model, it is possible to evaluate the effect of independent variables that is influential 243 on the answers to each question of the questionnaire. In general, all independent variables had a 244 significant effect on answering the questions of the questionnaire. 245 246 Discussion 247 As PD is known as predicator of some mental issues and disorders, Epidemiological studies of 248 PD can play a constructive role in determining the general mental health status of society, 249 identifying demographic factors related to it in the country. Having a significant sample size 250 available and using the LCR model, in this study, we were able to identify latent patterns of PD 251 among patients referred to Mashhad health centers and evaluate the factors related to these 252 patterns. 253 254 Using LCR, by entering the effect of auxiliary variables, the classification results were improved, 255 and three latent classes or different patterns in answering the questions of the K-6 questionnaire 256 were discovered. The first class consisted of 46% (no PD), the second class 40% (low PD), and 257 the third class 14% (severe PD). People in the severe PD class consistently reported most of the 258 symptoms, and in contrast, people in the no PD class never experienced these symptoms. A 259 similar study by Barragan et al. had similar results and among the four latent identified classes, 260 2.8% were classified as severely disturbed and 13.6% as moderately disturbed.36 The structure of 261 the formed classes showed that the level of sadness and grief among people, even in the no PD 262 class, is higher than other symptoms, which is a matter for consideration and needs further 263 investigation to find the cause. 264 265 On the other hand, the feeling of emptiness and worthlessness in all classes, even among people 266 with severe PD, was the lowest compared to other symptoms. Less of these symptoms may be 267 rooted in the culture and beliefs of the people, religious beliefs and values, relationships, and 268 solidarity between families, which despite the high mental pressures among individuals as a 269 protective factor, prevents people from the occurrence of such feelings. 270 271 Women are more prone to PD than men. The Barragan study in the United States found similar 272 results.36 Compared to women, men were less likely to be in the moderate anxiety class, mild 273 distress, and restlessness than in the non-anxiety class. 26 Factors influencing these results are 274 biological factors, environmental factors, gender roles, less social participation of women, and 275 their greater vulnerability in different life situations. In similar studies, mental distress had a 276 significant relationship with gender and it was more among women than men. 2, 23-25, 37 277 278 In addition, in Parsaei 's study regarding the quality of life among employees, men were 279 classified better in the quality of life class and had less depression and anxiety than women.24 280 281 Unlike Barragan's study, in which the age variable was not significant,36 the results of the present 282 study indicate that by increasing age up to 59 years, the chances of being in the class of severe 283 PD increase compared to no PD. However, this rate is lower for the low anxiety class in the age 284 group of 60-65 years compared to the 50-59 age group. The lower prevalence in the elderly than 285 in the 50-59 age group is probably due to many factors like support and respect of family 286 members, reducing their role in education and family finances, in other words, reducing the 287 burden of responsibility. On the other hand, increasing the prevalence due to age can lead to 288 improving the burden of responsibility and raising children, biological changes related to 289 adulthood, and social responsibility. In another similar study, PD had a significant relationship 290 with age.2 Also, a study in Japan showed that until 2016, the highest questionnaire score was 291 among women aged 25-29 and then 30-34 years old.23 292 293 According to DSM-5-TR, Psychological distress due to the different levels of life's traumatic 294 events and their contexts have diverse symptoms and forms.4 Women who are single, widow, 295 and divorced compare to married people are more likely to be in the two low PD and serve PD 296 classes which divorced people have the highest chance of belonging to them. The results of 297 Barragan's study also showed that married people are less likely to be in high, moderate, and 298 mild distress, restlessness, and restlessness classes.36 Murugan's study also showed a significant 299 relationship between PD and marital statu.2 However, because in the present study, most of the 300 widows and divorced people are women, the reason for the above results can be a bitter 301 experience in their life, enduring the pressure and responsibility of living alone, economic 302 pressures, child care, and family management. On the other hand, for single individuals, some 303 concerns may increase the likelihood of PD such as their concerns about marriage and choosing 304 a spouse, and also their concerns about the confusion of future life. 305 306 Findings showed that with increasing levels of education, the probability of severe and low PD 307 decreased. Similar studies was also consistent with our results. 2, 36 Probably the reason for the 308 high chance of illiterate people being in the class of severe and low PD can be attributed to the 309 inability and ignorance of these people to use appropriate methods of coping with stress, social 310 and cultural constraints. Also, it is noticeable that the reason for the decrease this value in 311 educated people is their greater ability to access information, to communicate and understand 312 more correctly the existing situations, to observe the principles of mental health and timely 313 prevention and necessary treatment, and finally to use appropriate methods to deal with stress. 314 Less chance of being in PD classes among people with a seminary education may indicate that 315 spirituality is involved in controlling emotions, and this can play a beneficial role in preventing 316 and treating mental illness and developing treatment plans for authorities. 317 318 Employees were less likely than unemployed people to report severe PD. This rate was lower 319 among government employees than the unemployed compared to the self-employed. In the 320 Barragan study, employees had a lower chance of getting into high and moderate PD than the 321 unemployed.36 Lack of income, fewer social relationships, the monotony of daily life, and lack of 322 influential position in society are probably the reasons for the high chance of suffering from PD 323 among unemployed individuals. Also, having a fixed income, insurance, pensions, and 324 employment facilities can be one of the reasons why governmental employees are less likely to 325 suffer from severe PD. 326 327 In our study, the higher prevalence of PD among urban residents than in the suburbs, similar to 328 the Jaisoorya study,25 can be due to many reasons such as more stress in urban society, high cost 329 of living, environmental pollution, reduced cultural content of human communication in large 330 cities. 331 332 People with normal weight are less likely to be in the class of severe and low PD. While 333 underweight people are more likely to have severe and low PD. This result may be related to the 334 reported severe symptoms of hopelessness in these people compared to others. Feelings of 335 hopelessness may also make them lose weight. However, the present study does not allow an 336 accurate assessment of the cause of this problem and needs further investigation in future studies. 337 338 Examination of the coefficients of the effective variables on the symptoms of PD or the 339 questions of the K-6 questionnaire showed that some variables, as well as being effective on the 340 classification method, also had a significant effect on the observed variables. In this study, 341 women reported more PD than men. Aging is also associated with increasing all symptoms 342 except hopelessness. By increasing age, disappointment will decrease and at younger ages, the 343 feeling of hopelessness is greater than in other ages. Married people experienced less distressing 344 symptoms than singles. 345 346 As mentioned, among the structure of the formed classes, the amount of sadness and grief in all 347 classes is more than other symptoms. Assessing the effect of auxiliary variables on the answer to 348 the question related to the feeling of sadness and grief also indicates that women, divorced 349 people, age-group of 40-49 years old and people with a diploma and undergraduate education are 350 more likely to experience the feeling of sadness and grief. After being exposed to a traumatic or 351 stressful event, PD is sometimes highlighted as anxiety or fear and in some cases as sadness. 7 352 353 Increasing the level of sadness and grief among this group of people, especially in the age group 354 of 40-49 years, who are community actives and have the greatest role in the progress and 355 development, can hinder the progress and dynamism of a society. Even if most of the people 356 studied in this age group are housewives, this is important because of the special role of women 357 in the home and family environment and their impact on spouses and the education of future 358 generations of society. 359 360 In this study, we tried to remove some of the limitations of previous studies, but this study also 361 had some limitations as well. In this study, we studied people who refer to health centers for 362 voluntary and optional action; some people with mental problems may not go to these centers 363 and so to this study. Consequently, underestimates the prevalence for the general public in this 364 study. Also, in health centers, health care workers complete the electronic file of individuals, 365 especially the K-6 questionnaire, and there is a possibility that individuals may not be honest in 366 answering the questions of the questionnaire; if the individuals themselves had completed the 367 questionnaire, they would have been more honest in answering the questions. On the other hand, 368 most of the women who went to the health centers were pregnant or mothers who came to 369 vaccinate their children, and we had a small percentage of single women in our database. 370 Naturally, due to the high sample size, one of the limitations of this study is the significance of 371 all demographic variables in fitting the regression model, which tried to solve this problem by 372 reporting the effect size. 373 374 Conclusion 375 According to the findings of this study, women than men, and divorced people than married ones 376 are more likely to experience severe symptoms of PD, considering that women are the 377 foundation of the family and the mother of the future generation of the country who they need 378 special attention and care. It is suggested that in addition to further research on the cause and its 379 clarification, the field of mental health in the family be provided through public education in the 380 mass media and schools. Also, health centers can increase their effectiveness by continuing 381 existing activities, focusing on these high-risk groups, and designing targeted interventions for 382 them. Given that cultural and social conditions can be effective in controlling and managing 383 emotions and stress, a similar plan can be implemented in other provinces and throughout Iran. 384 In the present study, it was observed that people in all classes of PD reported feelings of sadness 385 and grief more than other symptoms; it is suggested that in close future studies, this issue be 386 seriously addressed, and also the causes of this issue would be investigated. 387 388 Conflicts of Interest 389 The authors declare no conflict of interests. 390 391 Funding 392 This study was funded by the Mashhad University of Medical Sciences (ID: 971028). 393 394 Authors’ Contributions 395 JJ conceptualized, designed, and supervised this study. NS and SR cleaned and analyzed the data 396 and interpreted the results. 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J Fundam Ment Health. 515 2018;20(5):326-31. https://doi.org/10.22038/jfmh.2018.11400 516 517 https://doi.org/10.17795/nmsjournal28017 https://doi.org/10.1080/01621459.1997.10473658 https://doi.org/10.1007/BF02295837 https://doi.org/10.1080/10705511.2014.882690 https://doi.org/10.1080/10705510701575396 https://doi.org/10.1007/BF01246098 https://doi.org/10.1007/s10597-018-0273-5 https://doi.org/10.22038/jfmh.2018.11400 Table 1: Demographic characteristics of the subjects 518 Variables n (%) Gender Male 116056 (27.3) Female 309230 (72.7) Age 18-29 113149 (26.6) 30-39 182226 (42.8) 40-49 82418 (19.4) 50-59 42261 (9.9) 60-65 5232 (1.2) Marital Status Married 385424 (9.6) Widow 5448 (1.3) Absolute 4770 (1.1) Single 14152 (3.3) Education Level Illiterate 34129 (8.0) Diploma and sub-diploma 308337 (72.5) University 81642 (19.2) seminary 1084 (3.3) Job type Unemployed 8737 (2.1) Government employee 16261 (3.8) Freelance 80230 (18.9) Other 231884 (54.5) Residence Metropolis (non-marginal) 194859 (45.8) Suburbs 230427 (54.2) Body mass index Weight Loss 10735 (2.5) Normal weight 146726 (34.5) Overweight 141468 (33.3) Obesity 83869 (19.7) Total 425286 (100) 519 Table 2: Criteria for selecting the optimal number of latent classes 520 Number of classes LL BIC AIC AIC3 CAIC LMR BLRT 𝑹𝟐 entropy 2 Class -2368774 4737950 4737611 4737642 4737981 0.00 0.00 0.86 0.84 3 Class -2283160 4566812 4566396 4566434 4566850 0.00 0.00 0.79 0.78 4 Class -2262141 4524864 4524372 4524417 4524909 0.27 0.00 0.75 0.76 5 Class -2249907 4500488 4499919 4499971 4500540 0.00 0.00 0.65 0.69 2 Class -2368774 4737950 4737611 4737642 4737981 0.00 0.00 0.86 0.84 Table 3. The percentage of people in each class by the percentage of answers to each question of 521 the PD questionnaire. 522 questions of questionnaire answers no PD class low PD class severe PD class Question 1 Sadness Never / Rarely 55.0 15.0 1.0 Slightly 32.0 30.0 5.0 Sometimes 12.0 38.0 28.0 most of the time 1.0 15.0 45.0 Always 0.0 2.0 21.0 Question 2 Restless Never / Rarely 89.0 28.0 1.0 Slightly 10.0 42.0 11.0 Sometimes 1.0 25.0 37.0 most of the time 0.0 5.0 39.0 Always 0.0 0.0 12.0 Question 3 Nervous Never / Rarely 93.0 41.0 1.0 Slightly 7.0 39.0 12.0 Sometimes 0.0 18.0 42.0 most of the time 0.0 2.0 35.0 Always 0.0 0.0 1.0 Question 4 Helpless Never / Rarely 95.0 60.0 14.0 Slightly 5.0 26.0 22.0 Sometimes 0.0 12.0 37.0 most of the time 0.0 2.0 21.0 Always 0.0 0.0 6.0 Question 5 Hopeless Never / Rarely 96.0 58.0 6.0 Slightly 4.0 31.0 20.0 Sometimes 0.0 10.0 39.0 most of the time 0.0 1.0 27.0 Always 0.0 0.0 9.0 Question 6 Worthless Never / Rarely 99.0 77.0 23.0 Slightly 1.0 18.0 26.0 Sometimes 0.0 4.0 30.0 most of the time 0.0 1.0 15.0 Always 0.0 0.0 5.0 Class size 46.00 40.0 14.0 523 Table 4: Results of Independent Variables Regression on PD Classes Using LCR 524 Variables (Reference) low PD severe PD OR (95% CI) OR (95% CI) Age 18-29 Reference 30-39 1.21 ** (1.19-1.24) 1.61 ** (1.57-1.67) 40-49 1.42 ** (1.38-1.45) 2.49 ** (2.40-2.58) 50-59 1.65 ** (1.60-1.71) 3.21 ** (3.08-3.36) 60-65 1.77 ** (1.64-1.92) 2.90 ** (2.62-3.20) Gender Male Reference Female 1.18 ** (1.14-1.21) 2.85 ** (2.70-3.00) Marital Status Married Reference Widow 1.15 ** (1.07-1.24) 1.60 ** (1.43-1.74) Divorced 1.40 ** (1.30-1.51) 2.18 ** (2.00-2.37) Single 0.99 (0.95-1.04) 1.49 ** (1.40-1.58) Education Level Illiterate Reference Diploma and sub- diploma 0.99 (0.95-1.02) 1.00 (0.96-1.05) University 0.96 (0.93-1.00) 0.67 ** (0.64-0.71) Seminary 0.85 * (0.73-0.99) 0.54 ** (0.40-0.73) Job type Unemployed Reference Government employee 0.98 (0.92-1.04) 0.59 ** (0.54-0.66) Freelance 1.06 (1.00-1.11) 0.90 * (0.83-0.98) Other 1.08 ** (1.02-1.14) 0.96 (0.88-1.04) Residence Suburbs Reference Metropolis 1.06 ** (1.05-1.08) 1.16 ** (1.14-1.91) Body mass index Obesity Reference Weight Loss 1.09 ** (1.04-1.15) 1.38 ** (1.29-1.48) Normal weight 1.00 (0.98-1.02) 0.88 ** (0.85-0.91) Overweight 1.04 ** (1.02-1.06) 0.92 ** (0.89-0.95) *p < 0.05; **p < 0.01; Reference Category: No PD 525 526 527 Figure 1: A pattern of answering the questions of the K-6 questionnaire based on the LCR 528 model 529 u n e a s y m o n th 0 -1 M e a n re s tl e s s m o n th 0 -1 M e a n d e p re s s io n m o n th 0 -1 M e a n h a rd w o rk m o n th 0 -1 M e a n h o p e le s s m o n th 0 -1 M e a n w o rt h le s s m o n th 0 -1 M e a n 1.0 0.8 0.6 0.4 0.2 0.0