Pulmonary tuberculosis screening and quality of life among migrant workers , Northern Thailand

Introduction: The study aimed to estimate the prevalence of tuberculosis (TB) and to assess the quality of life and depression among the migrant workers in northern Thailand. Methodology: A cross-sectional study was conducted to elicit information among migrant workers in Chiang Rai and Pha Yao provinces, northern Thailand. Several standard forms including GeneXpert were used for data collection. A simple random sampling was used to select the companies and the study sample. Interview was conducted in a confidential room. Chi-square was used to detect the association between variables at the significant level α = 0.05. Results: Totally 467 migrant workers were recruited into the study, 97.9% were Myanmar national, 55.7% were males, and 51.4% were aged > 32 years. Only 2.1% were living in Thailand illegally, 23.8% had no health insurance, and 92.1% had monthly income at < 20,000 baht. Eight cases (1.71%) were at risk of TB disease from the screening, only one case was positive for TB disease from GeneXpert, and no multi-drug resistant detected. 47.5% had a low level of knowledge and 28.7% had a negative attitude on TB prevention and care. 10.7% were in a moderate to severe stage of depression. Six variables were found the significant associated with quality of life; ethnicity, sex, marital status, income, length of working in Thailand, and insurance. Conclusions: Besides active TB surveillance system, inter-country public health policy should be developed to cope with depression problem and improve quality of life among the migrant in Thailand


Introduction
Tuberculosis (TB) is a major cause of human infectious diseases especially in developing countries [1].TB leads to one of the public health problems in the area of the epidemic of HIV/AIDS [1,2].A number of TB cases have been detected yearly [1].A large amount of money was spent for health care system and health utilization regarding TB treatment and prevention programs [3].Even though many public health interventions were implemented in the past years throughout many organizations, TB is still ranked as one of the top threats to human health [4].Beside HIV/AIDS patients, migrant workers are one of the most vulnerable for TB infection [5].
In 2018, more than 2 million migrant workers in Thailand [6].Majority are Myanmar, Cambodia, and Lao PDR [6].Chiang Rai and Pha Yao are located in northernmost of Thailand and are defined as significant border areas in the aspect of international trade and economic activities in the northern region of Thailand [7].There is a large economic growth in previous years in these areas in both agricultural and industrial areas [7].Therefore, there was need to add a number of workers to the economic development plan.Since these two provinces share a border with Myanmar and Lao PDR, many workers from these two countries favor to work in Chiang Rai and Pha Yao province.Chiang Rai and Pha Yao Provincial Department of Labor Protection and Welfares reported 21,447 and 866 workers working in Chiang Rai and Pha Yao provinces respectively [6].Most migrant workers are allowed to work in Thailand legally, but some of them are working illegally [6,8].
Quality of life and depression are good indicators used to predict the standard of living [9][10][11].It also can be used as one of the key performance indicators of the development in various areas including economic and health care system developments [12].Assessing the quality of life among some vulnerable populations such as migrant workers is important in order to understand the situation and standardize relevant systems to improve public service as a whole particularly among those with limited access to public services [13].
There is few information available in TB prevalence and also the level of quality of life of migrant workers in northern Thailand.Therefore, the study aimed to investigate the prevalence of TB and also the quality of life among migrant workers in northern Thailand.The information could be used for policy development according to TB care and prevention among the migrant workers, and also used for health care system development to provide a proper health care service to them.Ultimately, could be support the goal of world health organization (WHO) in elimination of TB burden globally [14].

Study design
A cross-sectional study design was used to elicit the information from the participants.

Study setting
The study was conducted in Chiang Rai and Pha Yao provinces.In 2017, Department of Labor Protection and Welfare [8] reported that totally 242 companies in Chiang Rai province, and 111 companies in Pha Yao province employed non-Thai workers in their company.All targeted companies were private businesses.
Department of Labor, Chiang Rai Provincial was contacted to get the list of the companies that having non-Thai employees.A simple random method was used to select 13 companies in Chiang Rai, and 5 companies in Pha Yao provinces.After selecting the companies, it was found that the total number of migrant workers were met the requirement of the study.Appointment was made after verbally contacting in all accepted companies.After reaching the selected companies, a short meeting with the manager was initiated to provide all essential information regarding the study.

Study population
Non-Thai workers in companies in Chiang Rai and Pha Yao provinces were the study populations.There were 9,624 workers in 2016 who were non Thainationals (Myanmar and Lao PDR) in these two provinces.

Inclusion criteria
a) non-Thai workers, b) aged  18 years old, c) worked at a study setting at least one year at the date of data collection.

Exclusion criteria
a) participants who could not provide essential information regarding the study protocols, and b) could not identify her/his nationality.
From the calculation, at least 302 participants were needed for the analysis.Adding 10% (30 participants) for any errors in the study, therefore, 332 participants were required.All migrant employees who were working at the selected companies and met the selection criteria were invited to participate the study.

Research instruments
Questionnaire, a 5-item TB screening form, SF-12 [10], PHQ-9 [17], and GeneXpert (Cephied GeneXpert IV) [18] were used as the research instruments.Questionnaire was developed from the literature review and consultation with experts in relevant field.There were 6 parts.Part I consisted of 18 questions regarding the general characteristics such as nationality, age, sex, religion, income, number of family members, ability to use Thai, etc.In item of "income", it was classified into category;  20,000 baht, and > 20,000 baht per month, which was based on the average income of Akha hill tribe in Thailand who had similar characteristics to the migrant workers, at 20,000 baht/family/month [19].In the item of "length of working in Thailand", it was classified into two categories;  7 years, and > 7 years, due to the average working time in Thailand of the migrant workers at 7 years [8].
Part II consisted of 4 main questions regarding the information of work place such as type of company, number of workers, registration status of the company, etc.Part III consisted of 11 questions regarding the medical history and rights to access health care system such as history of TB, history of TB in their family, HIV testing, diabetes mellitus (DM) and hypertension (HT), etc.Part IV consisted of 5 questions regarding risk behaviors such as smoking, alcohol use, meth amphetamine, etc.Part V consisted of 10 questions to detect the level of knowledge regarding TB prevention and control.Part VI consisted of 10 questions to detect the level of attitude regarding TB prevention and control.Part VII was the standard form assessing quality of life (SF-12).Part VIII was the standard form assessing depression (PHQ-9).Part IX was for the laboratory.
Questions regarding knowledge were tested using Kuder-Richardson (KR) [20], only question that gained ≥ 0.75 were pooled into the study.Questions related to both knowledge and attitudes were tested for reliability by pilot test with 20 selected samples from one of the companies in Muang District, Chiang Rai province.In this process, feasibility and reliability were detected by Alpha Cornbrash coefficient [21].The overall questionnaire score was 0.77.

Quality and interpretation of SF-12
The SF-12 is used for assessing health related quality of life (HRQOL) which consisted of 12 questions.Question no.1-5, and 8 were used to detect the physical health status or physical component score (PCS).The Internal consistency coefficients were > 70%, and reliability was 83% [10].Question no.6-7, 9-12 were used to detect the mental health status or mental component score (MCS).Before interpretation, the raw scores were conversed to the transformed scale which is shown on 0-100 scales.Interpretation; having SF-12 a score of ≤ 50 means low quality of life, and a score of > 50 means high quality of life.

Quality and interpretation of PHQ-9
The PHQ-9 is a multipurpose instrument for screening, diagnosing, monitoring and measuring the severity of depression.It has 84% sensitivity and 93% specificity for major depression [17].It composts of 9 questions with 4 answer scales: "Not at all", "Several days", "More than half the day", and "Nearly every day".Then, the total score is 27.Those who have > 9 score are in a normal group, 10-14 scores are in a mild group, 15-19 scores are in a moderate group, and > 20 scores are in a severe group.

Process of questionnaire development
The questions in part I-VI were developed from the literature review and consultation the experts in the field.After the first draft, researchers came up with discussions in terms of possibility, feasibility, and covered the content according to the objectives of the study.The questionnaire was tested for validity by the Index Objective Congruence (IOC) [23], which was assessed by three external experts who were working in the relevant field.Questions that gained >0.7 were included in the final form.Whereas questions with a score 0.5-0.7 were developed before they were included in the final form.

Data gathering procedures
After getting 18 companies as the target study settings, in Chiang Rai and Pha Yao province, all employees who met the inclusion criteria were invited to participate in the project.Before staring the interview, all participants were asked to obtain the informed consent form.
An interview was conducted in a private and confidential room by a researcher.Those who were found positive of TB screening were asked to obtain sputum specimen and it was stored in a specific media before sending it to the laboratory for detection by GeneXpert technique at Chiang Rai Provincial hospital.All the processes in the fieldwork lasted 30 minutes each.

Statistical analysis
Data were double entered into excel sheet.Data was analyzed by SPSS version 24; (IBM, Armonk, NY).Both descriptive and inferential statistics were used for data analysis.General characteristics were explained by means, standard deviations, and percentage.Chi-square and Fisher exact test were used to detect the association between variables at the significant level α = 0.05.Fisher exact test was used in the place of chi-square, in case of having a small number of expected frequencies in a cell.

Ethical considerations
The study including its materials was approved by both the Human Research Ethics Committee of Mae Fah Laung University, Chiang Rai, Thailand (No. REH 600-18), and Human Research Ethic Committee of Chiang Rai Public Health Provincial Office (No. 25/2560) before commences.An interview was conducted in a confidential and private room at their working place.A small gift was provided to appreciate their participation.All completed questionnaires were immediately destroyed after coding and entering into the excel sheet.Data were kept in personal computer with security code.

Results
Totally 467 participants were included in the analysis.Four selected companied refused to participate the study.All migrant workers who met the criteria participated the study.Majority were Myanmar nationals (97.9%).Proportion between sexes was mostly equal, and a half of participants were aged > 32 years (51.4%).Majority were Buddhist (98.9%), and married (80.3%).Six persons had a history of detention.A few persons were living in Thailand illegally (2.1%).One-fourth had no health insurance (23.8%), and 92.1% had monthly income less than 20,000 baht.
Only three persons had previous TB diagnosis, and 6.8% had been tested for HIV/AIDS.One-third had no history of BCG vaccination (Table 1).
Only one-fourth were able to speak Thai (28.8%), able to read Thai (29.5%), and a few were able to write Thai (3.6%).Regarding health behaviors; 19.3% smoked, 25.9% used alcohol, and nobody reported on use of amphetamine, heroin, and opium.Majority were working in industrial sectors (69.6%), lived at work place (86.7%) which was prepared by the company, and 71.1% had two or more people living together.However, most of them lived in places with poor ventilation (70.0%).
Regarding TB screening, eight persons (1.71%) had a positive for at risk of TB disease.On a closer look, it was found that six cases were Myanmar nationals, and two cases were Laos nationals (six were males and two were females).However, after detection by GeneXpert, only one person was positive for TB (12.5%), and no multi-drug resistant.
The average level of knowledge in TB prevention and care was low (47.5%).Four variables were found to be statistically different in level of knowledge of TB prevention and care; ethnicity (p-value < 0.001), income (p-value = 0.03), status of working in Thailand (p-value = 0.028), and length of working in Thailand (p-value = 0.018) (Table 2).In comparison of level attitude regarding TB prevention and care and the general characteristics, three variables were statistically different; income (pvalue = 0.02), working status in Thailand (p-value = 0.001), and length of working in Thailand (p-value = 0.001) (Table 3).
Twenty-six persons had a moderate level of depression (5.6%), and another 24 persons had a severe stage of depression (5.1%).In a comparison of depression among the participants by characteristics, three variables were statistical different; ethnicity (pvalue = 0.01), length of working in Thailand (p-value < 0.001), and health insurance (p-value = 0.001) (Table 4).
According to the quality of life indifferent characteristics of the participants, six variables were found the significant associated with quality of life; ethnicity, sex, marital status, income, length of working in Thailand, and insurance (Table 5).

Discussion
The prevalence of pulmonary TB among the participants was 0.21%.It coincides with the study conducted in Samut Sakhon province in 2015 which reported the prevalence at 0.20% among the Myanmar migrant workers [24].In 2017, World Health Organization (WHO) reported Thailand was ranked the 22 nd country in the world with the highest TB burden, and approximately 93,000 new cases yearly, 16% of whom were also HIV positive [25].Thailand is defined as one of the countries with the highest burden of TB and HIV/AIDS problem particularly in northern region [25].
Under the regulations of Thailand, all legal migrant workers must be certified free of TB disease; therefore, most legal migrant workers in Thailand are free of TB disease at the date of entry into Thailand.Those detected with TB disease during entry into Thailand were sent back to their home country for treatment [26].
In our study, one case was detected in an illegal migrant worker.In fact, illegal migrant workers are facing double vulnerabilities in both burden of access to care and avoiding being charged by the police.The international labor organization reported that there were 3.3 million migrant workers in Thailand (51% were Myanmar nationals, 37% were Cambodians, and 12% were Lao PDR nationals), approximately 8.5% of country's lobour force in low-skilled jobs [27].More than half of the migrant workers are in Thailand illegally [28].
Most migrant workers in Ching Rai and Pha Yao earn less than 20,000 baht per family per month.This number is greater than those who are working in Myanmar with approximately 3,744 baht per month per family [29].Many people from Myanmar and Lao PDR favor to work in Thailand for better income.Many studies reported on the association of poverty and the risk of TB infection [30][31][32].It could be assumed that migrant workers in Thailand are vulnerable for TB infection especially in the era of HIV/AIDS which is a major influencing factor of TB epidemic in Thailand [33].
Under the universal coverage, all Thai nationals have been provided free health care on almost all health problems while accessing public hospitals [34].It covers 99.87% of Thai population [35].However, this does not cover migrant workers.Therefore, this might a barrier to access healthcare and getting proper medical checkup for migrant workers while being suspected of TB infection.This is supported by the study of Tchirhart, et al. [36] which reported that insurance, and access to free or low-cost services were major factors affecting access to health care system among migrant TB patients.Moreover, migrant TB patients are in serious need of health system response along the Thailand-Myanmar border [37].Therefore, migrant workers particularly those who are living in Thailand illegally are insecure regarding access to health care system.
Besides working status and right of free access to health care system of migrant workers, quality of life and depression are also significant problems.The study among the migrant workers in Singapore reported that females were living in low quality of life compared to the general population [38].The study among nurse migrant workers in the United States found that they have a low quality of life compared to native nurses [39].Moreover, the study among the migrant workers in Germany found that migrant workers were associated with low quality of life particularly in mental aspect [40].In our study, it was found that males had a significantly lower quality of life than females.
In our study, it was found that more than 10% of the migrant workers are in the mild and severe stage of depression but no difference between sex and age categories.Janssen-Kallenberg, et al. [41] reported that older age and low socioeconomic status are associated with severe depression among the Turkish migrant workers.More than 50% were positive for depression among the Moroccan-Dutch migrants [42].
There are some limitations in the study.A crosssectional study design is a powerful design to estimate the prevalence of health problem particularly where there is high prevalence.However, in our study, only 8 cases were positive for the screening test, and one case was found positive for TB disease.It is less powerful to detect factors associated with TB among the migrant workers.Moreover, adjusting all potential confounder factors may not possible in a cross-sectional study.
Another limitation is only workers who are working in a registered company were recruited into the study.There are many other illegal migrant workers working in other unregistered companies such as small agricultural farms, and some other small service businesses.Therefore, the participants in the study somehow did not represent all migrant workers.Those workers are more vulnerable for TB infection because they are working illegally and it could be assumed that they were not certified free of TB before entry to Thailand.
In the study, 4 companies declined to participate in the study after first contact.The main reason was time availability.However, it might be due to having many illegal workers in their companies.

Conclusion
Most migrant workers are legally working in Thailand.Only one-fourth have health insurance.Majority are Myanmar nationals working less than 7 years, and receiving low monthly income.A few cases have a positive screening of TB and only one case was found with TB disease with none MDR-TB detected.A half of them have low level of knowledge in TB prevention and care, and one-third have low level of attitude in TB prevention and care.Ten percent are in moderate and severe stages of depression and one-third are on low quality of life.Even though there were few participants with TB infection among the migrant workers, collaborations between countries are still needed for effective TB surveillance and control.Moreover, improving quality of life and solving depression problems among the migrant workers in Thailand should be intended from national and international relevant agencies.

Table 2 .
Comparisons of knowledge in TB prevention and care among the participants.

Table 3 .
Comparisons of attitude in TB prevention and care among the participants *Significant level at α = 0.05; a Fisher exact test.

Table 4 .
Comparisons of depression in participants by characteristics.

Table 5 .
Quality of life among the participants.