Our study shows that some key elements of PCT approach are implemented inadequately by health workers. This may compromise patient adherence and ultimately treatment outcomes. Still a quarter of the patients were not given a choice by health workers concerning the place of treatment. If health facility-based treatment is forced upon the patients adherence may be compromised if the distance between patients’ residences and the health facility is too big . Furthermore, it precludes health workers from engaging in other important daily tasks [15–17]. However, if patients are forced to follow home-based DOT, this may also result in poor treatment adherence especially when they do not have a reliable treatment supporter. The fact that only about 14% of those who were given the choice felt they had enough time to think of the two options and identify a suitable treatment supporter may lead to a wrong choice with regard to the treatment supporter, or even result in health facility DOT although they prefer home based DOT.
The study revealed that patients and treatment supporters do not seem to be properly informed about TB by health workers. This is of particular relevance since health workers identified health education as a pivotal factor in promoting treatment completion. Adequate knowledge about the spread of TB during treatment may prevent unnecessary social isolation, while understanding the duration of treatment gives the patient a better perspective about his/her abilities in the near future . Taken together, this information will guide the patient and supporter through the period of TB treatment and without it maintaining adherence to therapy may be challenging.
Providing information on the potential side effects of TB drugs did not appear to be a priority for a significant number of healthcare providers, since approximately one third of patients did not receive any information on side effects. It has, however, been documented that drug side effects negatively influence adherence to treatment  and patients who experience such events are more likely to discontinue treatment .
Although health workers did not adequately instruct patients and supporters, they nevertheless identified the importance of health education and reliable treatment supporters as factors which positively influence patient adherence and successful treatment outcome. Additional health education given to newly diagnosed TB patients may motivate them to complete TB treatment , and the support of family members appears to have a strong positive influence on patient adherence to treatment .
Checking returned blister packs from home-based patients was the primary method by which health workers assessed patient adherence. This corresponds with NTLP guidelines for treatment adherence. However, WHO recommends that counting empty blister packs is not an acceptable method for determining adherence, especially in the case of multidrug-resistant treatment .
Two factors appear crucial for improving improve health workers’ performance and ultimately the effectiveness of the PCT delivery strategy. Firstly, health workers should be re-trained and made aware of the key elements of PCT. Secondly, regular supportive supervision and mentoring of health workers by the district health authorities are indispensable for ensuring the quality of TB care. The scale-up of PCT through dissemination of new guidelines without any training shows that this is an inadequate strategy. With guidelines not being followed, and health workers not being supervised, the initial positive PCT results may be compromised, leading to de facto TB self-treatment, higher rates of non-adherence and an increase in the prevalence of drug resistance.
The NTLP of Tanzania has welcomed this evaluation and identified the need for health worker training. In collaboration with other partners, it has produced an educational film for health workers, patients and treatment supporters that provides a simplified explanation of all the main steps and elements of PCT. The video is distributed to every hospital and health centre with TB services and functioning DVD/TV devices. When distribution of this educational tool is accompanied by supportive supervision of health workers by well-trained Regional and District TB and Leprosy Coordinators, PCT can be implemented successfully in Tanzania.
The presented study has limitations. The dominant local languages sometimes had to be used in the rural districts of Kahama and Mufindi (Kisukuma and Kihehe, respectively) where respondents were not able to express themselves fluently in Kiswahili, with the risk of possible information bias from these respondents. However, health workers who were not involved in TB treatment undertook the interviews, with care workers or community members serving as interpreters, and back-translation was undertaken immediately to reduce the potential for bias.
Although the data were collected in 2007, a year after scale-up of the PCT approach in Tanzania, it is unlikely that the findings have been superseded. Since the scale-up, there have been no changes with respect to treatment allocation or observation. If anything, the need for training and regular supportive supervision is now more urgent than ever.