98 JOURNAL OF PUBLIC HEALTH Concerning: Screening for tuberculosis: more to be done

We read with great interest the study of Brewin et al.1 regard-ing the important topic of the level of acceptability of screen-ing for tuberculosis among immigrants. However, we would like to make some comments on the methodology followed by the authors and on the validity of the results. According to the authors, there was a significant level of acceptability of screening, because only four individuals interviewed declined it for various reasons. It would be inter-esting if the authors reported the relative frequency of the subjects who agreed to participate in the screening procedure during the period of the screening offer. Although the authors claim that their findings are novel, there are previ-ously published studies that report acceptability rates. In a primary care clinic for refugee claimants in Canada, Levesque et al.2 describe that 76.7 % of the participants accepted tuber-culin skin test. In another study3 which was conducted by a social worker and non-governmental organization in Bilbao, Spain, the participation ratio was 75.4%. Carvalho et al.4 reported that although screening for latent tuberculosis infection was offered to 649 undocumented immigrants, only 33 % of them accepted it. It is also noteworthy that the samples of the aforementioned studies consisted of>200 subjects. Brewin et al. used a constant comparison approach to search for deviant cases and thus strengthen the validity of their results. However, even though grounded theory is widely used and has specific advantages, we believe that the integration of a qualitative method in the study would add to its validity.5 The sample of the study does not seem to represent prop-erly the distribution of the countries of origin of the immi-grants living in the United Kingdom.6 For example, although immigrants coming from Pakistan formed 7.85 % of all immi-grants entering the United Kingdom in 2004 (except fo