'International Union Against Tuberculosis and Lung Disease'
Doi
Abstract
Introduction
The burden of tuberculosis (TB) in Sweden is concentrated among migrants
from high TB incidence countries. The incident cases in Sweden arise mainly through
reactivation of a latent tuberculosis infection (LTBI) acquired in the home country or during
transit. Progression from LTBI to active TB disease can be prevented through treatment with
anti-tubercular medicines. LTBI screening is therefore offered for asylum seekers and
refugees in Sweden as part of a voluntary health examination (HE). Little is known about
their experiences of LTBI screening and treatment. In addition, there has been no previous
evaluation of the cost-effectiveness of the current LTBI screening policy in Stockholm or
Sweden.
Aims
The overarching aim of this thesis was to determine the cost-effectiveness of the
current strategy of screening for LTBI among asylum seekers in Stockholm. This aim was
achieved through the following specific objectives: 1) to assess the methodology of
previously published economic models of LTBI screening and to develop an analytical
framework, 2) to understand the experiences of asylum seekers with HE, 3) to quantify
health-related quality of life (HRQoL) of LTBI patients and to explore the factors influencing
it, 4) to quantify the HRQoL of TB patients, and 5) to assess the cost effectiveness of LTBI
screening through an economic model.
Methods
A qualitative study was designed to explore the experiences of asylum seekers with
HE; semi-structured interviews were conducted based on an interview guide. For the HRQoL
studies, a HRQoL instrument, EQ-5D, and a mental health screening instrument, RHS-15,
were used. For the LTBI patients, a mixed-method design was used, in which a crosssectional
survey using the EQ-5D and RHS-15 instruments was combined with qualitative
interviews of a subgroup. For the TB patients, a longitudinal study design was used in which
a cohort filled the EQ-5D instrument at the beginning and the end of treatment. A literature
review was performed to assess the methodology of published economic modelling studies of
LTBI screening. Through this review a framework was developed guiding the development
of an economic model (a Markov model) to assess the cost effectiveness of the current LTBI
screening in Stockholm compared to a hypothetical scenario of no screening. The analysis
adopted the societal perspective, and results were presented in term of incremental costeffectiveness
ratios (ICERs); taking 500 000 SEK/QALY as a cost-effectiveness threshold.
Results
The HE was perceived as available by asylum seekers, with no serious physical or
financial accessibility problems. They felt respected and trusted by the healthcare workers.
However, information about the Swedish healthcare system was perceived to be incomplete
and the HE was seen as non-responsive to their individual needs with main focus on
infectious diseases. Among LTBI patients, 38% screened positive for mental health concerns
using RHS-15, and 28% scored problems on mental health dimension of EQ-5D. These
patients expressed fear of being contagious to others, an ambiguous threat of a vague
diagnosis and future uncertainties about developing TB disease. However, LTBI patients had
no overall HRQoL decrement. TB patients had a HRQoL utility score of 0,72 at the
beginning of treatment, which improved significantly by the end of the treatment to 0,84. The
cost effectiveness results showed that ICER is the lowest among the age group 13 to 19 at
303 881 SEK/QALY, which was the only ICER below the 500 000 SEK/QALY threshold.
Discussion
Asylum seekers had a generally positive attitude towards HE, including TB and
LTBI screening, but also emphasized the need to broaden the focus on all health needs rather
than solely focusing on infectious diseases. LTBI patients might have a compromised mental
health partly linked to fear of TB disease. Therefore, it can be beneficial to address these
concerns as part of LTBI management. TB patients had a compromised HRQoL and a
decrement of 0,28 for TB patients is recommended to be used in economic evaluations. LTBI
screening among asylum seekers in Stockholm is cost effective in the age group 13 to 19
while it is moderately cost-effective in the age groups 0 to 12 and 20 to 34 years. The latter is
mainly due to the restrictive practices of offering treatment for persons over the age of 20
years.
Conclusions
Health examination is an acceptable, accessible health service. However, its
quality can be improved by broadening the focus beyond infectious disease control. An LTBI
diagnosis can be misunderstood as active TB and linked to stigma. The cost-effectiveness
analysis showed that screening is cost effective only when preventive treatment is offered.
Therefore, due to ethical and economic reasons, LTBI screening should only be performed
for asylum seekers who are potentially eligible for LTBI treatment