Antonio Alberto da Silva Lopes

Razões de proporções e uso do método delta para intervalos de confiança em regressão logística

OBJETIVO: Apresentar uma aplicacao da regressao logistica para estimar razoes de prevalencia ou risco relativo, e o uso do metodo delta para a estimativa de intervalos de confianca. METODOS: Utilizou-se o metodo delta, visto que esta tecnica e adequada para estimar variâncias de funcoes nao lineares de variaveis aleatorias, do tipo razao de proporcoes. O metodo baseia-se na expansao da funcao em serie de Taylor, provendo uma aproximacao para o calculo das variâncias. Para estimar as razoes de proporcoes e as respectivas variâncias, que permitem a estimacao dos intervalos de confianca, desenvolveu-se programa utilizando-se o modulo matricial do SAS. A aplicacao pratica do modelo proposto e feita utilizando-se dados de um estudo transversal com uma amostra de 611 mulheres, para testar a hipotese de que a falta de compartilhamento do trabalho domestico associa-se com altos escores de sintomas psicologicos medidos atraves de um questionario validado. As razoes de prevalencia calculadas atraves da regressao logistica, e os intervalos de confianca estimados pelo metodo delta foram comparadas com os resultados obtidos pela tecnica de Mantel-Haenszel. RESULTADOS: As estimativas pontuais das razoes de prevalencia brutas, cruas ou ajustadas, obtidas atraves da regressao logistica, foram semelhantes as encontradas na analise tabular. Tambem os limites dos intervalos de confiancas para as razoes de prevalencia atraves do metodo delta foram praticamente iguais em relacao aos encontrados atraves da tecnica de Mantel-Haenszel. CONCLUSOES: Os resultados apoiam o uso do metodo delta para estimar intervalos de confianca para razoes de proporcao. Esse metodo deve ser visto como uma alternativa para situacoes em que o efeito em estudo (variavel dependente) nao e raro, situacao onde a odds ratio se afasta das medidas epidemiologicas caracterizadas como razao de proporcoes.

Formas graves de leptospirose: aspectos clínicos, demográficos e ambientais

Characteristics of 1,016 patients hospitalized with leptospirosis in the Hospital Couto Maia, Salvador, BA, Brazil, between 1993 and 1997 are described. Higher pluviometric precipitation was related to an increase in the number of hospitalizations during the following month. Males corresponded to 81.1% (824/1,016) of these; mean age was 35.7+/-15.4 years. Almost 94% (778/829) of the 829 patients with information about race were black or mulatto (mixed race). For ages 18 years or above, almost 93% had not completed high school level. The mean incubation period was estimated as 6.3+/-3.9 days. Average duration of symptoms was 6.1+/-2.4 days. Hemorrhagic events corresponded to 14.3% (145/1,016). The case-fatality rate among 1,009 patients that were not transferred was 14.2% (143/1,009). Renal failure was the attributable cause of death in 76.2% (109/143). The data indicate that leptospirosis is closely related to lower socioeconomic levels, and that higher pluviometric precipitation antecedes the outbreaks.

Handgrip Strength as a Simple Indicator of Possible Malnutrition and Inflammation in Men and Women on Maintenance Hemodialysis

OBJECTIVEnTo assess the validity of handgrip strength (HGS) as a simple screening instrument for malnutrition and inflammation in patients on maintenance hemodialysis (MHD) by correlating it with malnutrition-inflammation score (MIS).nnnDESIGNnCross-sectional analysis of the Prospective Study of the Prognosis in Chronic Hemodialysis Patients (PROHEMO).nnnSETTINGnSatellite dialysis units in the city of Salvador, Brazil.nnnPATIENTSnThe sample included 274 men and 162 women on MHD. MAIN PREDICTOR VARIABLE: HGS was chosen as the main predictor variable in this study.nnnMAIN OUTCOME MEASUREnAn MIS ≥6.nnnRESULTSnAs compared with men, women were found to have lower HGS values (19.38 ± 6.48 kg vs. 29.07 ± 8.67 kg; P < .001) and higher MIS (6.38 ± 3.84 vs. 5.57 ± 3.39; P = .032). HGS was found to be inversely correlated with MIS among women (Spearmans ρ = -.360; P < .001) as well as men (Spearmans ρ = -0.384; P < .001); this inverse correlation was observed in patients with and without diabetes, different racial groups, younger and older subjects, incident (<3 months) and prevalent patients, in the case of both genders. Among both men and women, every one standard deviation lower of HGS was associated with more than two-fold higher odds for MIS ≥6, after adjusting for age, race, duration of dialysis, and Kt/V. These associations remained statistically significant after more extensive adjustments. The optimized cutoff point of HGS for MIS ≥6 was 28.3 kg for men (sensitivity = 70.0%; specificity = 66.0%) and 23.4 kg for women (sensitivity = 87.0%; specificity = 43.0%).nnnCONCLUSIONSnLower HGS values were independently associated with higher MIS among patients on MHD across several subgroups. These results suggest that HGS is a valid screening instrument for malnutrition and inflammation in patients on MHD.

Comparações de medidas de qualidade de vida entre mulheres e homens em hemodiálise

OBJECTIVE: To compare men and women on chronic hemodialysis in relation to their scores in health-related quality of life (HRQOL) and evaluate the potential influence of age and comorbidities on the comparison. METHODS: Cross-section of the baseline data of 254 women and 349 men, participants of the PROHEMO Study that has been developed in dialysis units of Salvador. By using the version of the Kidney Disease Quality of Life Short Form KDQOL-SF, validated for the Brazilian population, the following scores were determined: physical component summary (PCS), mental component summary [MCS] and the scale for symptoms/problems related to renal disease. The PCS and MCS scores were derived from the eight generic KDQOL-SF scales. Multiple linear regression was used to estimate differences in the scores of men and women (DS), adjusted for age, years on hemodialysis, heart failure, cerebrovascular disease, peripheral vasculopathy, diabetes, serum hemoglobin and serum albumin. RESULTS: Mean ages were 48.1±14.1 and 49.4±14.0 years for women and men, respectively. Women had lower scores for all generic HRQOL scales. They also had significantly (P<0.001) lower scores for PCS (DS = 2.4 points), MCS (DS = 3 points) and symptoms/problems (DS = 6.6 points). Differences were independent of comorbidties and greater in the group over 49 years of age. CONCLUSION: Data indicate that for several scales of HRQOL, women treated chronically by hemodialysis had lower scores than men. Lower scores in women were observed for different age groups, independently of comorbidities.

Complicações da hipertensão arterial em homens e mulheres atendidos em um ambulatório de referência

OBJECTIVEnTo assess the association between sex and left ventricular hypertrophy, stroke, and renal failure in hypertensive patients in a referral outpatient care unit.nnnMETHODSnThis study assessed 622 hypertensive patients diagnosed with left ventricular hypertrophy based on electrocardiography, renal failure based on serum creatinine level > or = 1.4 mg/dL, and stroke based on a previous history and physical examination. Logistic regression was used to estimate the odds ratio of the association between sex and target-organ lesions in hypertension adjusted for race, age, and duration of the disease.nnnRESULTSnThe mean age of the patients was 48.4 +/- 13.8 years; 74.1% were women, and 84.9% were mulattos or blacks. Almost half of the men and more than 40% of the women had had at least 1 definite event involving a target-organ lesion. The incidence of renal failure was greater among men [adjusted OR (ORa) = 2.73, P= 0.002]. In white patients, the incidence of stroke was significantly (P= 0.017) greater among men (4/33) than among women (0/56), and, in the age group > or = 49 years, the prevalence of left ventricular hypertrophy was significantly greater among men (ORa = 1.99, P= 0.024).nnnCONCLUSIONnThe data obtained suggest a greater prevalence of renal failure in men than in women, of stroke in white men than in white women, and of left ventricular hypertrophy in men than in women aged 49 years and above.

Electrocardiographic alterations in patients hospitalized with leptospirosis in the Brazilian city of Salvador.

OBJECTIVEnTo report the frequency and types of electrocardiographic alterations in patients with leptospirosis in the first 24 hours of hospitalization.nnnMETHODSnWe analyzed the electrocardiograms of 157 patients admitted to the Hospital Couto Maia in the city of Salvador, in the State of Bahia, Brazil, from March 1998 to June 1999. The electrocardiograms were performed in the first 24 hours after hospital admission, independent of the clinical manifestations of the patients.nnnRESULTSnThe mean +/- SD for patients age was 35.5+/- 13.7 (median = 32) years, and jaundice was present in 95.5% of them. Alterations in the electrocardiogram were detected in 68.2% (107/157) of the patients (95% confidence interval = 60.6% - 75.1%). Atrial fibrillation was the most frequent arrhythmia, occurring in 10.8% (17/157) of the patients. Other frequent findings were alterations in ventricular repolarization detected in 38.9% (61/157) of patients and first-degree atrioventricular block in 10.2% (16/157). The patients with atrial fibrillation were older and had higher levels of creatinine and aminotransferases.nnnCONCLUSIONnIn this sample, approximately 2/3 of the patients had electrocardiographic alterations after hospital admission. Of the major arrhythmias, atrial fibrillation was the most frequent, and the patients with this arrhythmia had evidence of more severe disease. The relation between the presence and type of electrocardiographic alteration and the prognosis of leptospirosis is yet to be assessed.

Assessment of the psychological burden associated with pruritus in hemodialysis patients using the kidney disease quality of life short form.

PurposeTo assess whether depression symptoms, poor sleep and dry skin bother explain association between pruritus and the burden of kidney disease in maintenance hemodialysis (MHD) patients.MethodsCross-sectional study of 980 patients from a prospective study in dialysis units of Salvador, Brazil (PROHEMO). The Kidney Disease Quality of Life Short Form was used to determine scores of kidney disease burden (KDB) and sleep with higher scores indicating lower perceived burden and better sleep quality, respectively. The Center for Epidemiological Studies Depression Scale was used for depression symptoms.ResultsPrevalence of severe pruritus (very much or extreme) was 19.4%. Significantly (Pxa0<xa00.001) lower mean KDB score by 11.44 points was observed for patients with severe pruritus (34.18xa0±xa027.51) than for those with no pruritus (45.62xa0±xa030.73). Severe pruritus was associated with poorer sleep quality, higher odds of dry skin bother and higher depression symptoms score. Association of pruritus with KDBscore was virtually eliminated after adjustment for sleep, dry skin bother and depression symptoms.ConclusionsThis study shows strong associations of severe pruritus with higher depression symptoms, poorer sleep and dry skin bother among MHD patients. The results support special attention to MHD patients with pruritus who often face high psychological burden.

Comparison of an intravenous pulse of methylprednisolone versus oral corticosteroid in severe acute rheumatic carditis: a randomized clinical trial.

OBJECTIVESnTo compare the short-term prognosis of patients with severe acute rheumatic carditis when treated with an intravenous pulse of methylprednisolone in comparison with conventional treatment using oral prednisone.nnnMETHODSnWe designed a randomized clinical trial in the setting of a university general hospital in Brazil. We randomly allocated 18 patients with the diagnosis of severe acute rheumatic carditis and congestive heart failure to receive an intravenous pulse as opposed to oral prednisolone. Methylprednisolone was administered in a dose of 1 g intravenously for 3 consecutive days in the first and second weeks, for two days in the third, and one day in the fourth week. Prednisone was administered in a dose of 1.5 mg/kg/day over the period of 4 weeks.nnnRESULTSnThe mean age of the patients was 11.1 +/- 3.7 years, with a median of 12 years. Patients on oral treatment showed a more pronounced decrease in the heart rate, sedimentation rate, and in the titres of C-reactive protein than those receiving intravenous therapy. At the end of treatment, a mild decrease in the left ventricular end-systolic dimension was found in those having oral treatment, compared to an increase in the group having intravenous treatment (p = 0.036). The ejection fraction showed a median increase of 5% in those undergoing oral treatment, and a median decrease of 6% in the group with intravenous therapy (p = 0.009). There were 5 therapeutic failures in those receiving intravenous therapy (56%), including 1 death. Therapeutic failures were not observed in those treated orally (p = 0.03).nnnCONCLUSIONnIntravenous treatment of methylprednisolone, as a single anti-inflammatory agent, was inferior to conventional treatment with oral prednisone in the control of severe rheumatic carditis.

Inadequação de tromboprofilaxia venosa em pacientes clínicos hospitalizados

BACKGROUND: The risk of venous thromboembolism (VTE) is high in hospitalized patients, however it can be reduced by adequate prophylaxis. OBJECTIVE: To evaluate the adequacy of VTE prophylaxis in hospitalized medical patients. METHODS: A cross-sectional study was performed in hospitalized patients with acute medical illnesses in 4 hospitals of Salvador. RESULTS: We evaluated 226 consecutive patients: 15.5% in medical ICU, 79% > 40 years of age and 48% male. The majority (97%) had a least 1 risk factor (RF) for VTE, 79% had reduced mobility and 62% were diagnosed as having a RF at admission. Of the 208 prophylaxis candidates, 54% received some form of prophylaxis: unfractionated heparin (UFH) in 44%, low molecular weight heparin (LMWH) in 56% and mechanical methods in 2 patients. The utilization rate was similar in private and public hospitals. (51% vs. 49%), but LMWH was more common in private hospitals, without a residence program (97%), and UFH in the public ones (86%). LMWH was more frequently used than UFH in patients > 40 years of age, more often in Caucasian than in Black patients, and less frequently in those with contraindications for heparin. Of the 112 patients receiving prophylaxis, 63% received adequate dosages: LMWH in 95.2% and UFH in 20.4%. VTE prophylaxis was adequate in only 33.6% (70/208) of the patients. CONCLUSION: Risk Factors for VTE were frequent in medical patients. There was considerable variability of the VTE prophylaxis prescribed in private and public hospitals. LMWH was used more appropriately than UFH. However, only a minority of patients candidates for prophylaxis, received adequate dosages.

Potentially modifiable factors associated with non-adherence to phosphate binder use in patients on hemodialysis

BackgroundDespite the evidence that phosphate binder (PB) is associated with improved outcomes many hemodialysis patients do not adhere to prescribed PB regimen. Therefore, barriers to PB adherence should be identified and eliminated. The purpose of this study was to evaluate PB adherence among hemodialysis patients and to explore potentially modifiable factors associated with low PB adherence.MethodsA cross-sectional study (502 patients) was performed in four dialysis units in Salvador, Brazil, using data from the second phase of the Prospective Study of the Prognosis of Chronic Hemodialysis Patients (PROHEMO). Patients were categorized as adherent or non-adherent to PB based on their responses to a semi-structured questionnaire.ResultsNon-adherence to PB was observed for 65.7% of the patients. After adjustments for numerous covariates, cerebrovascular disease (odds ratio (OR), 3.30; 95% confidence interval (CI), 1.03-10.61), higher PTH (OR per each 300xa0pg/mL, 1.14; 95% CI, 1.01-1.28), lack of comprehension of the appropriate time to use PB (OR, 7.09; 95% CI, 2.10-23.95) and stopping PB use after feeling better (OR, 4.54; 95% CI, 1.45-14.25) or feeling worse (OR, 11.04; 95% CI, 1.79- 68.03) were significantly associated with PB non-adherence. By contrast, the adjusted odds of PB non-adherence were lower for patients with more years on dialysis (OR by each 2xa0years, 0.87; 95% CI, 0.80-0.95), with serum phosphorus above 5.5xa0mg/dL (OR, 0.53; 95% CI 0.34-0.82), who referred that were encouraged by the dialysis staff to be independent (OR, 0.52; 95% CI 0.30-0.90), and reported that the nephrologist explained how PB should be used (OR, 0.20; 95% CI 0.05-0.73).ConclusionThe results of the present study are encouraging by showing evidence that improvement in the care provided by the dialysis staff and the attending nephrologist may play an important role in reducing the high prevalence of non-adherence to PB in maintenance hemodialysis patients. A new questionnaire is presented and may help to evaluate systematically the patients regarding PB adherence in hemodialysis setting.