Progression of null or mild lower urinary tract symptoms indicative of benign prostatic hyperplasia after 2 years of follow-up in non-treated men aged 40 years or older.

OBJECTIVES: After screening men aged 40 years or older for lower urinary tract symptoms (LUTS) indicative of benign prostatic hyperplasia over the years 1999 to 2000, non-treated men with an initial International Prostate Symptoms Score (I-PSS) equal to or lower than 2 were assessed 2 years later for symptom progression. METHODS: A cross-sectional study was conducted in 1999 on 1804 men aged 40 years or older who were living in Madrid. In a telephone interview sociodemographic information was requested and LUTS assessed using the I-PSS. Of 975 men with no LUTS or lower than 2 in this baseline survey, 463 were re-interviewed in 2001. The dependent variable was the change from null/mild to moderate/severe LUTS produced over 2 years. RESULTS: Over the 2-year period, the mean increase in I-PSS score was 2.20 (95% CI, 1.89-2.51). The cumulative incidence of progression from asymptomatic/mild to moderate/severe disease was 9.94% (95% CI, 7.53-13.00). In the multivariate logistic regression model men who lived in a rural setting (OR, 2.70; P = .01) and armed forces, qualified agriculture and fishing workers (OR, 4.11; P = .05) were independently associated with progression. Age and alcohol intake were also found to interact; intake of 0.01-25.99 g/day in men older than 50 years (OR, 0.28; P = .008) was related to a lower frequency of progression than the same alcohol intake in men younger than 50 years (OR, 2.03; P = .380). CONCLUSIONS: After the 2-year period, the incidence of symptom progression was 10% in men aged 40 years or older with an initial I-PSS equal to or lower than 2.

Diagnostic validity of helical CT compared to ultrasonography in renal-ureteral colic.

OBJECTIVES: Helical CT without contrast is currently being evaluated for the diagnosis of renoureteral colic. Ureteral obstruction and other pathologies with similar symptoms can be rapidly identified. This study intends to evaluate the validity of CTh for these patients and to compare it with the ultrasound technique in order to consider the CTh as an efficient diagnostic alternative for these pathologies. METHODS: A diagnostic evaluation study was carried out between January 2004 and December 2006 in patients with persistent renoureteral colic after standard care. They were blindly evaluated by ultrasound and CTh, maintaining the follow up until the "gold standard" confirmation. Qualitative variables were described by frequency and 95%CI and quantitative variables by position and dispersion measures. The Chi2 test was used to compare qualitative variables. Validity indicators and 95% CI were calculated and compared with McNemar test. RESULTS: 124 patients were studied. Lithiasis and the other diagnosis had frequencies of 59.7% and 40.3% respectively. The percentage of lithiasis obtained by ultrasound (92) was 22.8% and by CTh (124) was 59.7%. Validity indicators for CTh were superior to 95%, with 100% sensitivity and positive predictive value. Ultrasound specificity and positive predictive value were 100%, but sensitivity was only 29.6% (p<0.05). CONCLUSION: CTh can be considered a good alternative diagnostic technique in the renoureteral colic management.

Risk of upper gastrointestinal complications among users of traditional NSAIDs and COXIBs in the general population.

BACKGROUND & AIMS: Traditional nonaspirin, nonsteroidal anti-inflammatory drugs (tNSAIDs) have been associated with a 3- to 5-fold increased risk in upper gastrointestinal complications (UGIC). Whether use of selective inhibitors of cyclooxygenase-2 (COXIBs) will translate into a clinically relevant reduced toxicity has not been widely investigated in the general population. METHODS: We conducted a nested case control study using The Health Improvement Network Database identifying 1561 cases of UGIC between January 2000 and 2005. A random sample of 10,000 controls was frequency matched to the cases by age, sex, and calendar year. RESULTS: The adjusted relative risk (RR) of UGIC associated with current use was 3.7 (95% CI: 3.1-4.3) for tNSAIDs and 2.6 (95% CI: 1.9-3.6) for COXIBs. Daily dose was a predictor of increased risk for both tNSAIDs and COXIBs. Users of tNSAIDs with a prolonged plasma half-life or slow release formulations had an augmented risk of UGIC. Overall, the estimate of RR associated with COXIBs was 0.8 (95% CI: 0.6-1.1) compared with current use of tNSAIDs, and, among nonusers of aspirin, the corresponding estimate of RR associated with COXIBs was 0.6 (95% CI: 0.4-0.9). CONCLUSIONS: COXIBs present a better upper gastrointestinal safety than tNSAIDs, although the risk of UGIC for an individual drug is determined by its daily dose and plasma drug exposure in addition to its selectivity for cyclooxygenase-2. Also, concomitant use of aspirin is a strong effect modifier of COXIBs that negates the superior gastrointestinal safety over tNSAIDs in the absence of aspirin use.

[Systematic review about the usefulness and prognostic value of the p53 oncoprotein and proliferation marker Ki-67 for upper urinary tract transitional cell carcinoma]. / Revisión sistemática sobre la utilidad y el valor pronóstico de la oncoproteína p53 y el marcador de proliferación Ki-67 en el car- cinoma de células transicionales del tracto urinario superior.

OBJECTIVES: To perform a systematic review on the expression and prognostic value of the p 53 oncoprotein and Ki 67 proliferation marker in transitional cell carcinoma of the upper urinary tract. METHODS: A systematic review of cohort, prospective and retrospective studies from 1/1/1990 to 11/24/2003 has been undertaken, performing a bibliographic search both manual and electronic in the main databases. 632 works were found using the keywords "ureter, renal and pelvis tumor", and 14 with "ureter, renal and pelvis tumor, and immunohistochemical". RESULTS: 509 patients were studied; they were selected from 7 retrospective studies about the usefulness of p53 and Ki 67 in transitional cell carcinoma of the upper urinary tract published between 1995 and 2002 (three Spanish studies, three Japanese and one North American). Each one analyzes between 37 and 121 cases, with a mean age of 66.8 years (range 63.0-74.7) and a predominance of male sex in 100% of the studies. The pyelocalyceal site was the most frequent in these series. Treatment is another issue taken into consideration in this papers, being nephroureterectomy the most frequently found. The p53 and Ki 67 percentage expression in various studies has been related to clinical and histological factors. Only 5 studies performed a multivariate analysis using Cox regression models. Three of them deal with Ki 67 and two with p53, although one of the p53 studies associates cyclin E determinations. Only two out of three studies about Ki 67 were considered evaluable, because multivariate analysis was not performed in the other one. CONCLUSIONS: 1) There are a few studies and they are very heterogeneous in terms of design, selection criteria, follow-up, and use of prognostic variables. 2) The analyzed studies establish that oncoprotein p53 and proliferation marker Ki 67 are prognostic factors for transitional cell carcinoma of the upper urinary tract, and 3) To perform a meta-analysis was deemed not indicated because of the heterogeneicity of the studies found in our search.

[Variable measurement in urologic clinical research]. / La medición de las variables en la investigación clínica urológica.

Epidemiology develops measurements that allow to quantify the occurrence of disease within the population. There are three types of measurements: frequency measurements, explained in this article; association measurements, between the occurrence of disease and some characteristics, the effect of which on the disease is what they intend to measure; and measurements of the potential impact that modification or disappearance of some risk factors would have on the occurrence of disease in the population. The first objective of epidemiological studies is the knowledge of the frequency of disease. There are three basic measurements of frequency of a disease. Prevalence measures the proportion of people that has it in a given moment. Cumulative incidence measures the proportion of people that convert from non-sick individual to sick individual during a specified period of time. Incidence rate is a measure of the instantaneous strength of occurrence of the disease.

[Statistics as support tool and not as a decision tool]. / La estadística como una herramienta de apoyo y no como una herramienta de decisión.

The use of statistics in medical articles has risen a lot during the last decades, however it is used in a thoughtless manner in many instances. Today, Statistics is the only tool that allows the medical researcher to obtain results and benefits from those studies the relationships of which can not be interpreted from a determinist perspective, because it is a branch of applied mathematics objective of which is to manage and quantify the uncertainty of the available information, to support decision taking. The objective of this article is to review the basic statistical concepts that every doctor should know to be able to perform and/or detect quality research, as well as to underline the most frequent errors committed when interpreting statistical results. We review the general concepts about data synthesis and differentiation of the different types of measurements, hypothesis testing and errors that can be committed doing it, the real meaning of the "p" value, differentiation between statistically significant and clinically relevant results, the importance of confidence intervals as a measure of significance and clinical relevance, the confusion generated between two concepts that are different as standard deviation and standard error, and the criteria that govern the selection of the adequate statistical tests to evaluate relationships between variables.

[Choosing study design in urologic research]. / Elección del diseño de estudio en investigación urológica.

The design of an epidemiological study includes the procedures, methods and techniques by which the researcher tries to obtain valid (avoiding systematic errors or bias) and precise (avoiding random errors) answers to the research question posed. This principal question aimed to be answered is the specific objective of the study, which guides the election of an adequate type of design. The objective of this article is to describe the classification criteria (finality, temporal sequence, directionality, and control of the assignation of different study factors) of the different types of epidemiological studies (experimental, almost-experimental, and observational) and the main advantages, disadvantages, utilities and objectives of each investigation design.

[Design and analysis of a study on reliability and validity of diagnostic tests in urological clinical research]. / Diseño y análisis de un estudio de fiabilidad y validez de pruebas diagnósticas en investigación clínica en urología.

Diagnosis is a process characterized by uncertainty, which the researcher can approach through knowledge based on the theory of probability, and, as such, it is part of the general decision-making process. To use a test is a process that helps to confirm or refuse the initial probability of the patient to be sick. In this article, we analyze the essential characteristics of diagnostic tests and the principles of effective evaluation of the studies about these tests. We explain in detail what reliability of an instrument is, the types of reliability that there are, and how to analyze them. So that, we introduce concepts such as Pearson's correlation coefficient, intra-class correlation coefficient, and Cohen's Kappa coefficient. Another topic described in this article is measurement of validity, defining the types of validity to be considered on an instrument. Finally, we treat the general principles that rule the design and execution of a study for the evaluation of diagnostic tests, the structure followed by these studies, and mainly the analysis, intention of which is to evaluate to what extent that diagnostic test differentiates between subjects with and without the disease studied. We explore the concepts of sensitivity, specificity, predictive values, and probability ratios, and ROC curves are explained.

[Writing an original research article]. / Elaboración de un artículo original de investigación.

Publication of a scientific work is the final and obligatory stage of any research. Among the various existing types of medical publications, the research original article is the prototype of scientific article. Its finality is to communicate the investigation undertaken to the reader in a coherent, clear and precise manner. With that purpose, the discoveries found by the authors as an answer to a hypothesis are presented and discussed. To send the original article to a biomedical journal, the manuscript should present some adequate formal characteristics, in addition to contain scientifically valid information. That can be achieved by complying with the rules past by the International Committee of Biomedical Journal Editors which have been adopted by a great number of scientific journals as publication requisites. The objective of this article is to describe the structure of the various parts (first page, abstract, introduction, material and methods, results, discussion, and bibliographic references) that constitute the format of the research original article, exposing the main adverse to be avoided during its preparation.