Tuberculosis in Spain: epidemiological pattern and clinical practice.

SETTING: Thirteen Autonomous Regions in Spain. OBJECTIVE: To study the incidence of all forms of tuberculosis (TB) and investigate clinical practice in TB. DESIGN: Cases of all forms of tuberculosis diagnosed in the study setting from May 1986 to April 1997 were identified though active search of different databases. Clinical and epidemiological information on cases was collected from clinical records or by interview with physicians. RESULTS: The overall incidence of all forms of tuberculosis was 38.5/100,000 and the incidence of smear-positive disease was 13.83/100,000. Most cases (97.1%) were Spanish nationals, with rates higher in men than in women (52.7/100,000 vs. 24.87/100,000) and in groups aged 25-34 and 75 years and over (61.35/100,000 and 59.35/100,000, respectively). Disseminated forms were frequent (6.6%), and the most common risk factor was human immunodeficiency virus (HIV) infection (17.7% of cases). Hospitalisation was common (71.6%). Microbiological confirmation of diagnosis was sought for 87.7% of the cases (91.8% of pulmonary vs. 75.5% of extra-pulmonary cases), and 65.2% were culture-positive (73.8% of pulmonary vs. 39.7% of extra-pulmonary cases). HIV-infected patients were treated in almost equal proportions with three or four drugs (49.7% and 48.2%, respectively), while HIV-negative cases or those whose HIV status was unknown were usually treated with three drugs. CONCLUSION: The epidemiological pattern of TB in Spain is different to other industrialised countries in the age distribution of cases and the proportions of foreigners and cases with HIV infection. Microbiological confirmation of diagnosis is more common in pulmonary than in extra-pulmonary disease, and treatment with four drugs more frequent in HIV-positive cases.

Quality control and data-handling in multicentre studies: the case of the Multicentre Project for Tuberculosis Research.

BACKGROUND: The Multicentre Project for Tuberculosis Research (MPTR) was a clinical-epidemiological study on tuberculosis carried out in Spain from 1996 to 1998. In total, 96 centres scattered all over the country participated in the project, 19935 "possible cases" of tuberculosis were examined and 10053 finally included. Data-handling and quality control procedures implemented in the MPTR are described. METHODS: The study was divided in three phases: 1) preliminary phase, 2) field work 3) final phase. Quality control procedures during the three phases are described. RESULTS: Preliminary phase: a) organisation of the research team; b) design of epidemiological tools; training of researchers. Field work: a) data collection; b) data computerisation; c) data transmission; d) data cleaning; e) quality control audits; f) confidentiality. Final phase: a) final data cleaning; b) final analysis. CONCLUSION: The undertaking of a multicentre project implies the need to work with a heterogeneous research team and yet at the same time attain a common goal by following a homogeneous methodology. This demands an additional effort on quality control.

Determinants of patient delay among tuberculosis cases in Spain.

BACKGROUND: Patient delay was investigated in a cohort of TB patients identified from May 1996 until April 1997 in 13 Autonomous Regions in Spain. The study covered almost 67% of the total Spanish population. METHODS: Data were collected from clinical records. Using unconditional logistic regression with two different cut-off points to define 'patient delay' (the median and 75th percentile), the association between patient delay and different factors was estimated. RESULTS: A total of 7,037 cases were included. Median and 75th percentile delays were 22 and 57 days respectively. Factors associated with patient delay greater than the median (p<0.05) were: non-respiratory symptoms of TB and age over 14 years, although the effect of age was not linear. Furthermore, an interaction was observed between intravenous drug user (IDU) and HIV status, in that, whereas patient delay was greater in IDUs than in non-IDUs among cases whose HIV status was either negative or unknown, among HIV-positive patients no such IDU-related differences were in evidence. Factors associated with extreme patient delay (greater than the 75th percentile) were essentially the same, but the above-described interaction disappeared, with IDU status showing no direct effect. In addition, likelihood of extreme patient delay increased in the case of alcoholism and female gender and decreased in the case of chronic renal failure, corticoid treatment, prison inmates and residents of old age homes. CONCLUSION: Although there is a universally enjoyed right to health care in Spain, some groups of TB patients could nevertheless be experiencing problems in seeking medical attention.