This study elucidated the understanding of time to intensive phase treatment interruption and its prognostic factors. The present sample was predominantly hospitalized, male and Malays participants with t low median family income. TB interruption rate reported in this study was high (23.7%) comparable to Liew et al.’s (45) local national study. The TB interruption rate yielded in the present study surpassed the national target of 2% and recent state surveillance data of 10.9% in 2018 (4,24). This finding was also comparable to studies conducted in Gambia (i.e., 20%) and Ethiopia (i.e., 25.2%) (25,29). This study concurs the latter studies, in terms of predominant hospitalized TB patients among the recruited participants. The fact that some of the socioeconomic characteristics of the present study as reflected by poor urban population profile (i.e., high unemployment and low median family income) are relative to Selangor’s median family income in 2016 (46). Poor urban groups were found to exhibit low socio-economic status, inadequate social assistance, vulnerable socio-behavioural profile, thus poor access to health care system (47,48). Above all, the variation across past prognostic studies could be attributed to the status of TB control programs in the respective country and methodological heterogeneity (in particular, operational definition of treatment interruption and duration of follow up to allow sufficient event) (32,33,43). The high interruption rate reported in this study therefore heightened the need for prompt intervention and policies which should be strategized systematically according to gathered evidence.
The median time to intensive phase treatment interruption was 56 days suggesting towards completion of intensive phase. It was comparable to the temporal evidence reported in Kenya (i.e., 56 days) and West Africa (i.e., 60 days) (31,49). Therefore, the transitioning interval from intensive to maintenance phase is crucial and should be thoroughly assessed, both in terms of cumulative social-behavioural impacts such as financial burdens, as well as health service factors especially in the flow management of referrals to other centres.
In this study, the event proportion was the highest in the first month of therapy which concurred the respective multi-centre evaluations in Kenya and Benin (30,31,50). Some salient postulations have been documented in previous studies including travelling away from the treatment site, and accumulated travel cost and financial burden (51,52). Therefore, the treatment interruption during intensive phase should be vigorously anticipated during the first point of contact between health providers and patients. This mainly to avoid rendering prolonged infectivity in the community, drug resistance, as well as financial burden and psycho-social impacts on individuals and health service system (6,9,35,53).
The significant effects of smoking status on TB treatment interruption endorsed a previous local finding in northern Malaysia reporting that current smokers had three times higher risk of treatment interruption compared to non-current smokers (54). The present study also extended previous studies by delineating a temporal association (55–58). Biologically, tobacco-induced cytochrome P450 enzyme could the plasma rifampicin levels in smokers, compromising the beliefs in effectiveness of treatment (59,60). In addition, smokers are often described as having a complex psychosocial risk profile, it is difficult if not impossible to under the relationship between smoking and unfavourable TB treatment outcomes (61). In the present study, our results have been adjusted for all of these psychosocial considerations such as alcohol consumption and illegal drug use. As the double burden of TB and smoking are prevalent in Selangor state, this finding should further inform the development of quit smoking program among TB patients.
The present study depicted that TB symptoms was negatively associated with treatment interruption. This is consistent with previous qualitative and empirical studies (50,58,62). On the one hand, less symptoms give rise to the feeling in patients that their illness is not severe enough and to the intention of seeking opinion from unreliable third parties, thereby leading to early withdrawal (63). On the other hand, experiencing more symptoms leads to fear that nurtures susceptibility and severity, hence motivations to persevere with treatment (64). It appears that sputum conversion and treatment response are frequently expedited in patients with mild symptoms which in turn induce the sensation of being cured, resulting in early drop out (65). This however, warrants further evaluations to explore the patterns of discontinuation of treatment among those with mild symptoms upon diagnosis.
In the present study, 226 participants (51.5%) depicted history of hospitalization upon starting treatment, thus in agreement with surveillance data reporting most of the TB cases in Selangor were started treatment at hospitals settings (66). In a large scale assessment in Cameroon, Pefura-Yone et al. identified that history of hospitalization was a protective factor in that prolonged hospitalization was meant to isolate the marginalized population (27). This inconsistent finding could be ascribed by diverse health service system and policy across the study locations. In Malaysia, some hospitalized TB patients would have subsequent DOTS monitoring at health clinics or other treatment centres. Thus, individual and health system changes occur during the transition phase of treatment need to be addressed via instituting appropriate measures that could minimize the probability of loss to follow-up during this period. In this regard, the special needs for ill hospitalized TB patients should be thoroughly evaluated, particularly on anticipating functional support gained by patients. In-ward management should also have the capacity of dedicated managing team to ensure that all recording and reporting for discharge or inter-facility referral are properly documented and communicated across the level of care.
The present study found that internalized stigma was the prognostic factor of treatment interruption (15,67), thus providing new empirical evidence from the local perspective. Some TB patients fear that other people see them as HIV/AIDS patients (68,69). Other TB patients experience the suppression of the self-esteem secondary to stigmatization, contributing to treatment avoidance (70,71). Likewise, in a qualitative study involving informants from seven states (Kuala Lumpur, Johor, Kelantan, Penang, Sabah, Sarawak, and Selangor) across Malaysia, public stigma was found to be derived from community and employers (72). The foregoing postulation warrants further evaluation of public stigma among local community by clarifying the different drives and dimensions of TB stigma, hence to endeavour the framework of stigma reduction strategy.
Our findings suggest that the longer waiting time spent by participants at the DOTS centre, the higher the risk of treatment interruption (14,73). This does not lend support to a meta-analytic study (74). In this light, several mechanisms were postulated. The experience of long wait is burdensome for patients, in the sense of frequent medical leave from their jobs, and impairs their income for living expenses, thus compromising the consistency of DOTS monitoring (72). In addition, longer waiting time undermines the patients’ satisfaction towards health system delivery, resulting in high drop out from DOTS (75). Meanwhile the waiting time at DOTS monitoring centre could be attributed by the disparity in staffing capacity, flow process of DOTS delivery, and facility resources in health centres. Therefore, the flow management of DOTS monitoring should be refined to optimize the capacity of providers and efficient process flow by taking the waiting time and infection control policy into due consideration.
No significant effects of health belief subscales on TB treatment interruption were reported in the present study. Our recent findings do not support Hill et al. (25). Perceived benefit was found to be a prognostic motivational factor of treatment interruption,but resembles previous conceptualization of motivational factors by Ajzen and Fishbein (76) which suggested the inconsistent effect of health belief domain on preventive behaviour. Instead, an elicitation study or focus group discussion is pre-requisite for a prospective study, primarily to identify the salient attitudinal or normative factor that is specific to the evaluated population (36).
No significant effects of travel distance on TB treatment interruption were reported. Our findings contradict previous claims that patients with a travel time of more than half an hour had a higher risk of default even after three months of treatment (25). The correlation between built-up cost over time and risk of defaulting was postulated. Our findings somehow could relate the evolvement of health service system in Malaysia. According to National TB Control Programme, patients were allowed to have DOTS monitoring at the nearest community clinic in their neighbourhood. This decentralization policy has contributed towards improvement of the travel distance among TB patients in Malaysia (4).
In essence, the present study provides local updates, beyond the biomedical attributes extracted from medical records or disease registry. The present study also offer a better understanding and simpler explanation of treatment interruption in the lights of psychosocial influence via IMB model framework. Therefore, the present findings may benefit involving organizations and policy makers in designing time relevant, theory based adherence strategies in TB case holding and management. Above all the present study was conducted at public health centre settings, thus limiting its generalizability to other study populations. Thus, future studies should be replicated to cater TB patients started their treatment at private facilities in an attempt to better understand TB treatment interruption in urban population.