**4. Proportion of LTFU**

The proportion of LTFU varies considerably among different countries, different types of TB, and different patient populations. It has been studied extensively and was found to be ranging from 2.5 to 44.9% [17–23]. A very high proportion (44.9%) of the patients were LTFU in rural northern Mozambique revealing that LTFU is a very serious problem [19]. In addition, systematic reviews and meta-analyses have estimated the mean proportion of multidrug-resistant TB patients who were LTFU. A 2009 systematic review of MDR-TB patients has found that this proportion is 12% [24]. Another 2009 systematic review also found a similar proportion of 13% [25]. However, a 2012 individual patient data meta-analysis found a higher proportion of 23% [26]. A rough literature review has revealed that the proportion of MDR TB patients who were LTFU ranges from 2.2 to 47% [27–43]. The figures vary vastly among different years, countries, and institutions, suggesting that the underlying factors responsible for these variations should be studied carefully.

However, few studies have reported on the proportion of LTFU among patients with extra-pulmonary TB. According to a French study, this proportion was 25% among lymph node TB patients [44]. Another study from Gabon reported that the proportion among cervical lymph node TB patients was 24.3% [45]. In India, among the miliary tuberculosis patients presenting with neurological manifestations, the proportion was 10% [46]. However, in Saudi Arabia, the proportion among CNS tuberculoma patients was reported to be 25.8% [47].

Another area of interest is latent TB since developed countries such as the USA and the UK are giving much attention to latent TB and its LTFU rate. Studies from the USA reported proportions ranging from 12 to 35.6% [48, 49]. In the UK, this proportion is 22.8% [50], and in Switzerland, 11% [51].

Attention should also be paid toward LTFU among certain special populations. The proportion of LTFU among childhood TB patients ranges from 4 to 37% [52–57]. Among the children with drug-resistant TB, it ranges from 5 to 19.09% [58–60]. These figures are much similar to those of the adult population. On the other hand, researchers from Côte d'Ivoire found out that the proportion of LTFU was rising among the elderly TB patients [61]. This is an area that researchers should explore more in the future.

We should not forget about our fellow healthcare workers since LTFU could lead to serious problems in the healthcare service setting. They are expected to have low rates of LTFU because of the medical knowledge they possess. Fortunately, a study from Morocco confirmed that the proportion of LTFU among healthcare workers

**115**

section.

*Loss to Follow-Up (LTFU) during Tuberculosis Treatment*

in the public sector was only 0.8% [62]. However, many studies need to be done to

Other populations of interest are prisoners and migrants. Northern Ethiopian prisons reported a low LTFU proportion of only 2.5% [63], which is an excellent result. In contrast, among the Ugandan prison inmates, 43% were LTFU and the odds are greater among the transferred prisoners [64]. On the other hand, researchers from the USA found out that 25.8% of the cases in a public health intervention were LTFU, and they were mainly undocumented migrants [65]. In such countries, as discussed above, even a single case of LTFU can cause an outbreak of TB. The same problem is arising in Australia where all of the detained illegal foreign fisher-

"Treatment completion in illegal foreign fishermen may be as low as zero; deporting fishermen before curative treatment is completed undermines TB control efforts and may lead to an emergence of drug resistance and an increased burden of

This is an area of concern that needs urgent measures. On the other hand, the International Organization of Migration is achieving great results among Vietnamese immigrants [67]. Only 7% of the MDR-TB patients from these migrants were LTFU. It is likely that such 'international intergovernmental' effort is necessary to tackle the problem of LTFU among the migrants since individual governments

Individual factors play a role in the process of being LTFU from treatment. Sometimes, the results may contradict between different studies, probably due to

Among the various sociodemographic characteristics, age is a recognized factor associated with LTFU. Studies from India, Brazil, and China revealed that elderly patients have higher LTFU [4, 68–70], whereas studies from Norway, Botswana, and South Africa suggested that adolescents have significant risk [8, 30, 71]. One study from the UK even suggested a wider range of age of 15–44 years as a high-risk group for LTFU [11]. Regarding gender, studies uniformly suggest that higher LTFU was found in males, as seen in Kenya, Ethiopia, Georgia, and Uzbekistan [7, 18, 41, 72]. Residence plays a role in the mechanism of LTFU. In Pakistan, the rural residence is associated with LTFU [73], whereas in Uzbekistan, the urban residence is associated with LTFU [18]. This may be caused by access to the treatment center since being far from the treatment center is also associated with LTFU [74]. Transportation should be improved to increase accessibility toward the treatment center. Alternatively, they could be built in the hard-to-reach areas. Both approaches include challenges, and ultimately, these challenges may be what cause LTFU. Further discussion regarding different providers will be given in the next

Education plays a role in the development of LTFU. Brazilian researchers have found out that less than 8 years of schooling increases the risk of LTFU [4]. In addition, scarce TB knowledge is a risk factor for LTFU [75], and better TB knowledge a protective factor [5]. Therefore, health education and proper counseling should

Financial factors should also be considered while giving treatment, and programs without such considerations will likely to result in high LTFU. A study from

the cultural, social, and other variations of the study settings.

always be at the heart of every anti-TB treatment program.

*DOI: http://dx.doi.org/10.5772/intechopen.81900*

men were LTFU [66]. They concluded that

are facing difficulties handling this problem.

**5. Factors associated with LTFU**

**5.1 Individual factors**

active TB disease in our region."

explore this area of study.

*Healthcare Access - Regional Overviews*

The patients who were LTFU have not completed the treatment regime. This can cause serious public health problems because these patients are at higher risk of drug resistance [11]. They continue to spread the potentially resistant bacilli to the public, infecting the public. This has been proved in a Bayesian mapping where LTFU has served as an important indicator for the distribution of TB patients [12]. Therefore, LTFU should be one of our primary concerns in the battle against TB. Even just a single case of LTFU could cause an outbreak of TB, as observed in countries with low incidence such as Norway [13, 14], USA [15], and Austria [16]. In such outbreaks, the index cases are mostly immigrants, spreading the infection to their families, friends, and other social networks. To further visualize this problem, we need to look into the proportion of LTFU among different countries in the

The proportion of LTFU varies considerably among different countries, different types of TB, and different patient populations. It has been studied extensively and was found to be ranging from 2.5 to 44.9% [17–23]. A very high proportion (44.9%) of the patients were LTFU in rural northern Mozambique revealing that LTFU is a very serious problem [19]. In addition, systematic reviews and meta-analyses have estimated the mean proportion of multidrug-resistant TB patients who were LTFU. A 2009 systematic review of MDR-TB patients has found that this proportion is 12% [24]. Another 2009 systematic review also found a similar proportion of 13% [25]. However, a 2012 individual patient data meta-analysis found a higher proportion of 23% [26]. A rough literature review has revealed that the proportion of MDR TB patients who were LTFU ranges from 2.2 to 47% [27–43]. The figures vary vastly among different years, countries, and institutions, suggesting that the underlying

However, few studies have reported on the proportion of LTFU among patients with extra-pulmonary TB. According to a French study, this proportion was 25% among lymph node TB patients [44]. Another study from Gabon reported that the proportion among cervical lymph node TB patients was 24.3% [45]. In India, among the miliary tuberculosis patients presenting with neurological manifestations, the proportion was 10% [46]. However, in Saudi Arabia, the proportion among CNS

Another area of interest is latent TB since developed countries such as the USA and the UK are giving much attention to latent TB and its LTFU rate. Studies from the USA reported proportions ranging from 12 to 35.6% [48, 49]. In the UK, this

Attention should also be paid toward LTFU among certain special populations.

We should not forget about our fellow healthcare workers since LTFU could lead to serious problems in the healthcare service setting. They are expected to have low rates of LTFU because of the medical knowledge they possess. Fortunately, a study from Morocco confirmed that the proportion of LTFU among healthcare workers

The proportion of LTFU among childhood TB patients ranges from 4 to 37% [52–57]. Among the children with drug-resistant TB, it ranges from 5 to 19.09% [58–60]. These figures are much similar to those of the adult population. On the other hand, researchers from Côte d'Ivoire found out that the proportion of LTFU was rising among the elderly TB patients [61]. This is an area that researchers

factors responsible for these variations should be studied carefully.

tuberculoma patients was reported to be 25.8% [47].

proportion is 22.8% [50], and in Switzerland, 11% [51].

should explore more in the future.

**3. The problem of LTFU**

**4. Proportion of LTFU**

world.

**114**

in the public sector was only 0.8% [62]. However, many studies need to be done to explore this area of study.

Other populations of interest are prisoners and migrants. Northern Ethiopian prisons reported a low LTFU proportion of only 2.5% [63], which is an excellent result. In contrast, among the Ugandan prison inmates, 43% were LTFU and the odds are greater among the transferred prisoners [64]. On the other hand, researchers from the USA found out that 25.8% of the cases in a public health intervention were LTFU, and they were mainly undocumented migrants [65]. In such countries, as discussed above, even a single case of LTFU can cause an outbreak of TB. The same problem is arising in Australia where all of the detained illegal foreign fishermen were LTFU [66]. They concluded that

"Treatment completion in illegal foreign fishermen may be as low as zero; deporting fishermen before curative treatment is completed undermines TB control efforts and may lead to an emergence of drug resistance and an increased burden of active TB disease in our region."

This is an area of concern that needs urgent measures. On the other hand, the International Organization of Migration is achieving great results among Vietnamese immigrants [67]. Only 7% of the MDR-TB patients from these migrants were LTFU. It is likely that such 'international intergovernmental' effort is necessary to tackle the problem of LTFU among the migrants since individual governments are facing difficulties handling this problem.
