[Multicenter cohort of patients with HIV infection in the Madrid south-eastern metropolitan crown (COMESEM): basis, organization and initial results]. / Cohorte multicéntrica de pacientes con infección VIH de la corona metropolitana sudeste de Madrid (COMESEM): fundamentos, organización y resultados iniciales.

BACKGROUND: In order to evaluate changes related to the effect of new anti-retroviral agents and preventive programs, cohort studies of patients with HIV in our environment are needed. METHODS: Cohort study of patients diagnosed of HIV infection in the five hospitals included in the Madrid metropolitan south-eastern crown (COMESEM), which attend a population of 1,300,000 inhabitants. RESULTS: A total of 5,532 patients had been recruited until August 2001 (with a follow-up of 34,227 patients-year). The male/female ratio was 3/1. As for the transmission mechanism, 72.9% were parenteral drug users (PDU), 13.7% heterosexuals (HTX) and 8% of males having sex with males (MSM). The maximal figure of diagnosis per year corresponded to 1991 for PDU, 1993 for MSM and 1995 for heterosexuals. A decline in the number of diagnosed patients was observed for all groups, but MSM showed an increase in the year 2001 for the first time. Notably, among HTX, a growing and sustained trend was observed of patients not born in Spain (0% in 1993 and 50% in 2001; p < 0.001). CONCLUSIONS: Establishing a large cohort of HIV infected patients based upon medium-sized hospitals is possible. The analysis of data derived from this cohort allows the early detection of changes in the clinical and epidemiological profile of HIV infection.

Cohorte multicéntrica de pacientes con infección VIH de la corona metropolitana sudeste de Madrid(COMESEM): fundamentos, organización y resultados iniciales / Multicenter cohrt of patients with HIV infection in the Madrid south-eastern metropolitan crown (COMESEN): basis organization and initial results

Fundamento. Se necesitan estudios de cohorte de pacientes con infección del virus de la inmunodeficiencia humana (VIH) en nuestro medio para evaluar los cambios relacionados con el efecto de los nuevos antirretrovíricos y los programas de prevención. Métodos. Estudio de cohorte de todos los pacientes diagnosticados de infección VIH en los 5 hospitales de la corona metropolitana sudeste de Madrid (COMESEM) que atienden a una población de 1.300.000 habitantes. Resultados. Hasta agosto de 2001 se han reclutado 5.532 pacientes (con un seguimiento de 34.227 pacientes año). Hay 3 varones por cada mujer. Por vía de transmisión, el 72,9 por ciento eran usuarios de drogas por vía parenteral (UDVP), el 13,7 por ciento heterosexuales (HTX) y el 8 por ciento hombres que mantienen relaciones sexuales con hombres (HSH). El máximo de diagnósticos por año correspondió a 1991 para los UDVP, 1993 para los HSH y 1995 para los heterosexuales. En todos los grupos se ha observado un declive en el número de pacientes diagnosticados, pero los HSH en el año 2001 muestran un incremento por vez primera. Entre los HTX destaca la tendencia creciente y mantenida de pacientes no nacidos en España (0 por ciento en 1993 y 50 por ciento en 2001; p < 0,001).Conclusiones. Es posible establecer una cohorte amplia de pacientes con infección VIH basándose en hospitales de tamaño medio. El análisis de los datos derivados de esta cohorte permite objetivar cambios en el perfil clínico-epidemiológico de la infección VIH de manera precoz (AU)

Heat waves in Madrid 1986-1997: effects on the health of the elderly.

OBJECTIVE: The objective of this paper is to analyse and quantify the effects exerted on summer mortality by extremes of heat, particularly among persons aged 65-74 and 75 years and over, groups in which mortality is higher. METHODS: The study included the period from 1 January 1986 to 31 December 1997, for all people aged over 65 years resident in Madrid, based on mortality due to all causes except accidents (ICD-9 codes 1-799), and circulatory (390-459) and respiratory (460-487) causes. Meteorological variables analysed were: daily maximum temperature, daily minimum temperature and relative humidity. To control the effect of air pollution on mortality we considered the daily mean values of sulphur dioxide (SO2), total suspended particulate (TSP), nitric oxides (NOx), nitrogen dioxide (NO2) and tropospheric ozone (O3). Univariate and multivariate ARIMA models were used. Box-Jenkins pre-whitening was performed. RESULTS: The results yielded by this study indicate a mortality increase up to 28.4% for every degree the temperature rises above 36.5 degrees C, with particular effect in women over the age of 75 years and circulatory-cause mortality. The first heat wave that leads to the greatest effects on mortality, due to the higher number of susceptible people and the duration of the heat wave, show an exponential growth in mortality. Furthermore, low relative humidity enhances the effects of high temperature, linking dryness to air pollutants, ozone in particular. CONCLUSIONS: Since a warmer climate is predicted in the future, the incidence of heat wave should increase, and more comprehensive measures, both medical and social, should be adopted to prevent the effects of extreme heat on the population, particularly the elderly.

A model for forecasting emergency hospital admissions: effect of environmental variables.

This study modeled patterns and trends in emergency hospital admissions at a hospital in Madrid, Spain. The purpose was to quantify qualitative associations that have been detected between such admissions and a number of environmental variables. The following data were used: unscheduled daily emergency hospital admissions, Madrid air pollution data, and meteorological data. Time-series analysis was performed, with Box-Jenkins modeling. A multivariate model was constructed, incorporating the different causes of admissions and the respective environmental variables. Statistically significant associations were found between hospital admissions and other variables, indicating relationships with temperature, relative humidity, and mean daily tropospheric ozone concentrations. Whereas the effect of heat on admissions was short term, that of cold was in evidence from the second week. The association with ozone showed a seven-day lag and basically manifested itself as an influence on admissions for circulatory disease.

Relationship between atmospheric pressure and mortality in the Madrid Autonomous Region: a time-series study.

This study set out to determine the possible influence of variations in atmospheric pressure on mortality in the Madrid Autonomous Region (MAR), taking into account the possible confounding effect of other atmospheric variables. The study was based on daily mortality data from the MAR Revenue and Excise Authority, meteorological data from Getafe Observatory and air pollution data from the Madrid Municipal Automatic Air Pollution Monitoring Grid. A time-series analysis was performed, using Box-Jenkins modelling and controlling for the respective confounding variables. Furthermore, the different variables studied (pressure, temperature, pollutants, etc.) were used to produce a multivariate model of the different causes of mortality. A significant association was found between anticyclonic trend and mortality with circulatory causes in the medium-long term and anticyclonic trend and mortality with respiratory causes in the long term.

A randomized trial of the discontinuation of primary and secondary prophylaxis against Pneumocystis carinii pneumonia after highly active antiretroviral therapy in patients with HIV infection. Grupo de Estudio del SIDA 04/98.

BACKGROUND: Prophylaxis against Pneumocystis carinii pneumonia is indicated in patients with human immunodeficiency virus (HIV) infection who have less than 200 CD4 cells per cubic millimeter and in those with a history of P. carinii pneumonia. However, it is not clear whether prophylaxis can be safely discontinued after CD4 cell counts increase in response to highly active antiretroviral therapy. METHODS: We conducted a randomized trial of the discontinuation of primary or secondary prophylaxis against P. carinii pneumonia in HIV-infected patients with a sustained response to antiviral therapy, defined by a CD4 cell count of 200 or more per cubic millimeter and plasma HIV type 1 (HIV-1) RNA level of less than 5000 copies per milliliter for at least three months. Prophylactic treatment was restarted if the CD4 cell count declined to less than 200 per cubic millimeter. RESULTS: The 474 patients receiving primary prophylaxis had a median CD4 cell count at entry of 342 per cubic millimeter, and 38 percent had detectable HIV-1 RNA. After a median follow-up period of 20 months (758 person-years), there had been no episodes of P. carinii pneumonia in the 240 patients who discontinued prophylaxis (95 percent confidence interval, 0 to 0.85 episode per 100 person-years). For the 113 patients receiving secondary prophylaxis, the median CD4 cell count at entry was 355 per cubic millimeter, and 24 percent had detectable HIV-1 RNA. After a median follow-up period of 12 months (123 person-years), there had been no episodes of P. carinii pneumonia in the 60 patients who discontinued prophylaxis (95 percent confidence interval, 0 to 4.5 episodes per 100 person-years). CONCLUSIONS: In HIV-infected patients receiving highly active antiretroviral therapy, primary and secondary prophylaxis against P. carinii pneumonia can be safely discontinued after the CD4 cell count has increased to 200 or more per cubic millimeter for more than three months.

Use of poisson regression and box-jenkins models to evaluate the short-term effects of environmental noise levels on daily emergency admissions in Madrid, Spain.

The relationship between environmental factors and hospital admissions has usually been analysed without taking into account the influence of a factor closely related to traffic in big cities, that is, environmental noise levels. We analysed the relationship between environmental noise and emergency admissions, for all causes and specific causes in Madrid (Spain), for the study period 1995-1997, using two statistical methods for the analysis of epidemiological time series data: Poisson autoregressive models and Box Jenkins (ARIMA) methodology. Both methods produce a clear association between emergency admissions for all and specific causes and environmental noise levels. We found very similar results from both methods for all and circulatory causes, but slightly different for respiratory causes. Around 5% of all emergency admissions can be attributed to high noise levels, with a lower figure for specific causes. Current levels of environmental noise have a considerable epidemiological impact on emergency admissions in Madrid. A reduction of environmental noise levels could be accompanied by a possible reduction in the number of emergency admissions.

[Influence of a day care hospital on the incidence of hospital admission of AIDS patients]. / Influencia del hospital de día en los requerimientos de ingreso hospitalario de los pacientes con SIDA.

BACKGROUND: Day care units have become an usual way of medical care for AIDS patients. However, their influence on the incidence of hospital admissions has not been evaluated. METHODS: Observational and longitudinal study of a cohort of 308 patients with aids diagnosed between 1990 and 1994 and followed-up to June 1996. The incidence of hospital admissions according to the hospital of follow-up (with or without day care unit) was analyzed. A multivariate analysis of the number of hospital admissions was performed using regression model adjusted to a distribution of Poisson. RESULTS: After AIDS diagnosis, the incidence of hospital admissions was 108 per 100 patient-years of follow up (21 days as inpatient per patient-year). Those patients controlled in the hospital with day care unit have less hospital admissions (relative risk after adjusting by CD4+ cells count and type of diagnostic disease: 0.64; CI95% 0.55-0.76), and less days as inpatient through their follow-up (11 to 31 days less). There was no difference in survival among patients followed in both hospitals. CONCLUSIONS: A day care unit decrease the incidence of hospital admissions in aids patients. This positive impact is more evident in patients with lesser CD4+ cell counts.

Modeling of air pollution and its relationship with mortality and morbidity in Madrid, Spain.

OBJECTIVE: Evaluation of the association between air pollution and mortality and morbidity is becoming ever more complex owing to changes in inner-city air pollution, marked by decreasing values for all main pollutants save those associated with traffic. This has led to the need for the study of new epidemiological scenarios in which most pollutants are below guideline values. Nonetheless, the health effects are significant. METHODS: This report presents the results of a statistically based model for real-time forecasting of mortality and morbidity in Madrid, with meteorological and pollution series serving as inputs. RESULTS AND CONCLUSIONS: Not only did the models perform well with correlation coefficients between predicted and observed values (r = 0.683 for mortality, r = 0.681 for morbidity), but they enabled quantification of the impact of air pollution on mortality and morbidity (with increases ranging from 1. 8% to 12% for mortality and from 2.3% to 18% for morbidity for a 25-microg/m(3) increase in pollutants). Moreover, attention should be drawn to the observation that the model proved to be easy to implement and operate on a routine basis.

Daily mortality in Madrid community 1986-1992: relationship with meteorological variables.

Daily mortality displays a seasonal pattern linked to weather, air pollution, photoperiod length, influenza incidence and diet, among which temperature ranks as a leading cause. This study thus sought to assess the relationship between temperature, relative humidity, wind speed and mortality in the Madrid Autonomous Region (Spain) for the period January 1986-December 1992, controlling for the effects of air pollution and influenza incidence. Daily data on maximum, minimum and 24-hour mean temperature, relative humidity and wind speed were matched against daily mortality. Transfer function was identified using the Box-Jenkins pre-whitening method. Multivariate time series regression models were used to control for the confounding effects of air pollution and influenza incidence. Separate seasonal analyses were carried out for winter and summer periods. A J-shaped relationship between outdoor temperature, relative humidity and daily mortality was found. Mortality proved to be inversely related to cold temperature (4- to 11-day lag) and directly related to warm temperature (1-day lag). High relative humidity during summer periods was negatively related to mortality. Thermal variation ascribable to Madrid's mesothermal Mediterranean climate was strongly related to daily mortality, even where air pollution and influenza incidence were controlled for.

Isoniazid preventive therapy in human immunodeficiency virus-infected persons. Long-term effect on development of tuberculosis and survival.

BACKGROUND: Although the short-term benefit of isoniazid prophylaxis in patients coinfected with human immunodeficiency virus (HIV) and tuberculosis has been shown, long-term benefits are unknown. METHODS: Historical cohort study in an acquired immunodeficiency syndrome unit at a tertiary referral hospital. A sample of 121 HIV-infected patients with positive results on a purified protein derivative test were followed up for development of active tuberculosis and survival. Patients who received isoniazid prophylaxis were compared with patients who did not receive prophylaxis. RESULTS: Of the 121 patients examined, 29 (24%) completed a 9- to 12-month course of isoniazid prophylaxis (median follow-up, 89 months), and 92 (76%) did not receive the drug (median follow-up, 60 months). Active tuberculosis developed in 46 patients (38%). The incidence of tuberculosis was higher among patients with no prophylaxis (9.4 per 100 patient-years) than among patients with isoniazid prophylaxis (1.6 per 100 patient-years) (P = .006). Risk for development of tuberculosis was associated with the absence of isoniazid prophylaxis (relative risk [RR], 6.55; 95% confidence interval [CI], 2.02-21.19). Death during the period of study was more frequent in patients who did not receive isoniazid (50/92 or 54%) than in patients who received isoniazid (7/29 or 24%) (P = .008). Median survival was more than 111 months in patients who received isoniazid compared with 75 months in patients who did not receive isoniazid (P < .001). In a proportional hazards analysis, the development of tuberculosis (RR, 1.88; 95% CI, 1.09-3.27), the absence of isoniazid prophylaxis (RR, 2.68; 95% CI, 1.16-6.17), and a CD4+ cell count lower than 0.20 x 10(9)/L (RR, 3.03; 95% CI, 1.39-6.61) were independently associated with death. Patients who received isoniazid had a longer survival after stratifying for the CD4+ cell count. CONCLUSIONS: Preventive therapy with isoniazid confers long-term protection against tuberculosis and significantly increases survival in patients dually infected with HIV and Mycobacterium tuberculosis.

Injecting drug use as risk factor for visceral leishmaniasis in AIDS patients.

In Madrid Region 6652 AIDS cases were diagnosed between 1982 and 1993. Visceral leishmaniasis (VL) was present in 166 (2.49%). VL frequency among injecting drug users proved higher than that for the other transmission categories (relative risk 2.57; 95% confidence interval 1.64-4.01). This could point to an alternative Leishmania transmission route via needle sharing.

[Non-Hodgkin's lymphomas associated with the acquired immunodeficiency syndrome. A multicenter clinical study of 77 cases]. / Linfomas no hodgkinianos asociados al síndrome de la inmunodeficiencia adquirida. Estudio clínico multicéntrico de 77 casos.

BACKGROUND: The aim of the present was to study the prevalence of non Hodgkin's lymphoma (NHL) in AIDS patients as well as the clinicopathologic characteristics, response to treatment and survival. METHODS: From January 1984 to January 1991, 77 patients with NHL associated with AIDS diagnosed in 9 hospitals in Madrid were retrospectively studied. RESULTS: Ninety-two per cent of the patients were men (mean age 30 years: range: 9-66 years), 62% were intravenous drug abusers and 20 (26%) homosexuals. Pathologic study determined that 62 (80%) patients had high grade NHL (44% small noncleaved), 17% immunoblastic and 20% unclassifiable, and 15 (20%) had intermediate grade (16% diffuse large cell) being all the cases of the B immunophenotype. Sixty-five per cent were in advanced stages and 69% had B symptoms. Extranodal localizations were present in 88%, bone marrow in 29% and CNS in 29%. Six cases had primary CNS lymphomas. 50% of the patients had less than 200 x 10(6)/l CD4 lymphocytes. Forty-seven patients were evaluable for response to chemotherapy: 12 (26%) showed a complete response 27 (57%) a partial response and 8 (17%) did not respond. Opportunistic infections developed in 18%. The estimated survival at 3 years was 14% (median 6 months). On univariate analysis the parameters related to the worst survival were: primary CNS lymphoma, liver involvement, lack of treatment response, LDH > or = 300 UI/l, alkaline phosphatase > or = 500 UI/l and ESR > or = 70 mm. CONCLUSIONS: Non Hodgkin's lymphomas associated with AIDS usually behave in an "aggressive" way with a high frequency of advanced stages, B symptoms, high grade histologic subtypes and extranodal involvement. Response to treatment is poor, bone marrow toxicity frequent and survival short.

[Elaboration and evaluation of a fast detection system of mortality using Fourier analysis. Study of a value with maximal deviation]. / Construcción y evaluación de un sistema de detección rápida de mortalidad mediante análisis de Fourier. Estudio de un valor con desviación máxima.

BACKGROUND: To calculate all causes weekly baseline mortality and an alarm threshold using Fourier analysis. To analyse the largest outlier detected in our series. METHODS: Madrid Undertaker database from October 1988 to September 1993, was used in the analysis. Orthogonal components were detected using Fourier analysis. Expected deaths and confidence limits were fitted using Serfling method. Alarm threshold was placed at a distance of 1.96 standard deviations above baseline. RESULTS: orthogonal frequencies with significant amplitudes corresponding to periods 26, 52, 104 and 156 weeks were detected. The second was the fundamental and its multiples were harmonics. In the time domain, baseline mortality showed a winter peak, declined to a summer plateau and presented its lowest level at the end of August. 21 weeks exceeded the alarm threshold. Of these 17 were related to influenza epidemics. The largest outlier corresponded to a heat wave in July 1991. CONCLUSIONS: A procedure similar to that proposed by R. E. Serfling (1963) to calculate baseline mortality, an alarm threshold and short term extrapolation using Madrid Undertaker database (C. Borrell, 1991) is presented. Madrid Undertaker database provide accurate and timely information about all causes mortality excess in Madrid.

[Changes in the spectrum of the diseases in patients hospitalized with HIV infection]. / Cambios en el espectro de enfermedades en pacientes hospitalizados con infección por VIH.

BACKGROUND: Infections in subjects with HIV-1 infection are a frequent cause of hospital admission. Knowledge of the entities which most often motivate hospitalization may aid in designing the most appropriate diagnostic and prophylactic strategies. The causes of hospital admission in individuals with risk practices for HIV-1 infection attended in a Department of Infectious Diseases in Madrid over a period of 4 years were analyzed. METHODS: The records of the patients admitted from 1989 to 1992 were retrospectively reviewed. The principal and associated diagnoses which led to hospitalization were considered. The admissions of the two years were compared. RESULTS: Bacterial pneumonias were the principal cause of hospitalization in the 2 years studied. Forty-five percent of the infections leading to hospital admission were not included among those defining AIDS. Tuberculosis was the most frequent opportunistic infection. Admissions due to pulmonary pneumocystosis, tuberculosis, toxoplasmosis, esophageal candidiasis and Kaposi's sarcoma decreased from 1989-1992. To the contrary, disseminated Mycobacterium avium complex infection and systemic infection by cytomegalovirus significantly increased over the same period. The incidence of other diseases such as endocarditis or leishmaniasis remained stable. More than half of the diseases were diagnosed in association with another entity during the same admission. Likewise, an increase in atypical forms of infections thus making diagnosis and treatment more difficult was observed. The first cases of multiresistant tuberculosis, all of rapidly fatal evolution, were identified in 1992. Mean hospital stay increased 30% and the rate of mortality was of 9% in 1989 and rose to 20% in 1992. CONCLUSIONS: The spectrum of infections which led to hospital admission of patients with HIV-1 infection has significantly modified over the last 4 years being related with the generalization of prophylactic medication for some opportunistic infections, the improvement of certain diagnostic techniques and more frequent ambulatory treatment of some diseases. The mean length of stay and hospital mortality have increased in the HIV+ population.

Risk for developing tuberculosis among anergic patients infected with HIV.

OBJECTIVE: To assess the risk for development of tuberculosis among anergic patients infected with the human immunodeficiency virus (HIV). DESIGN: Retrospective cohort study. SETTING: Tertiary referral center. PATIENTS: All HIV-infected patients who had a baseline positive protein purified derivative test (PPD) and delayed-type hypersensitivity skin tests. MEASUREMENTS: Development of active tuberculosis. RESULTS: Of 374 patients, 108 (29%) had positive results of PPD tests, 154 (41%) had negative results of PPD tests but no skin anergy, and 112 (30%) were anergic. Conversion of the PPD to positive was observed in 10 of 67 (15%) patients with previously negative results of PPD tests and no anergy and in 3 of 36 (8%) anergic patients who were retested during the follow-up period (mean, 26 months). The risk for active tuberculosis to develop in patients not receiving isoniazid chemoprophylaxis was similar in patients with a positive PPD test result (10.4 cases per 100 person-years) and in anergic patients (12.4 cases per 100 person-years) and higher in both groups than in nonanergic patients with a negative PPD test result (5.4 cases per 100 person-years). Tuberculosis was more frequent among intravenous drug abusers with no previous isoniazid treatment (63 of 290, 22%) than among homosexual men (0 of 29) or patients in other HIV transmission categories (0 of 31). Preventive therapy with isoniazid reduced tuberculosis development (4% as compared with 31%; P = 0.008). Among 15 anergic patients who had CD4 counts measured within 3 months of tuberculosis development, only 1 (7%) had more than 500 CD4 cells/mm3. CONCLUSIONS: Anergic HIV-infected patients are at high risk for development of tuberculosis. Anergic HIV-infected patients, in addition to HIV-infected patients with positive results of PPD tests, should be offered preventive therapy if they live in areas with a high prevalence of tuberculosis, at least when the CD4 count decreases to less than 500 CD4 cells/mm3.

[Age-period-cohort analysis of mortality caused by ischemic cardiopathy in Spain 1965-1985]. / Análisis edad-período-cohorte de la mortalidad por cardiopatía isquémica en España 1965-1985.

With the objective of studying the temporal evolution of ischaemic cardiopathy (IC), or coronary heart disease mortality, in Spain, we carried out a cohort analysis with conventional graphic techniques and modern statistical methods. This permits better understanding and quantification of the age-period-cohort effects and identification of the potential factors operating upon them. To this end, loglineal (Poisson regression) models were constructed of the IC mortality rates for both sexes, using the GLIM package, in which the regression coefficients are the natural Relative Risk (RR) logarithms of the various age groups (35-74 years), period of death (1970-1985) and birth cohort (1985-1960) with respect to the reference group mortality, controlled by the effect of other groups. In respect of the results, the maximum RR value corresponds to decrease year 1975, and falls progressively to 1985, though at all times remaining above the 1970 value. The effect of 1985, though less than 1980, does not present significant differences from the latter. Nevertheless, no clear cohort effect was found. As a probable explanation for the pattern observed, this would suggest recent changes in life style and in medical attention. There is a discussion of the consistency of the models selected with the graphical results and with present knowledge of the natural history of IC and with the evolution of its determining factors, together with validation of the models. In summary, the IC mortality patterns observed show an increase up to the mid-seventies, and stabilization from that date onwards, in all age and sex groups, which is consistent with an age-period effect.

[Design and validation of a questionnaire for screening of venous insufficiency of the lower limbs]. / Diseño y validación de un cuestionario para el screening de la insuficiencia venosa de miembros inferiores.

OBJECTIVE: To carry out a questionnaire type test for screening of Chronic Venous Insufficiency (CVI) of lower limbs (LL) to be applied to clinical assistance. DESIGN: Observational type epidemiological study and validation of a test. LOCATION: Fuencarral Health Centre (Madrid). PATIENTS: 100 patients with venous alterations of the lower limbs (cases) and 100 without alterations (control group) selected from the register of the Centre. The inclusion criteria was the presence of truncular varicose veins and/or valvular insufficiency detected by ultra-sound (Doppler). MEASUREMENTS AND MAIN RESULTS: 20 variables were studied possibly associated with the disease and which could be collected by means of a questionnaire. From the epidemiological study, 13 simple questions with a YES/NO answer were chosen for the questionnaire, which collected information on the different variables selected. The maximum number of points of the test was 30. The value of each question was based on the strength of association (ODDS Ratio) and on the degree of reliability of the answers. The sensitivity and specificity of the test taking 14 points as the cutting point, was 82% in both cases. The ROC curve is indicated. CONCLUSIONS: Owing to the high prevalence of CVI of LL and to the possibilities of preventive measures if an early diagnosis is carried out, this questionnaire type test is considered useful among people attending the Health Centre and to be able to select those who require a more detailed and expensive diagnosis examination.