Drug dosage individualization based on a random-effects linear model.

This article investigates drug dosage individualization when the patient population can be described with a random-effects linear model of a continuous pharmacokinetic or pharmacodynamic response. Specifically, we show through both decision-theoretic arguments and simulations that a published clinical algorithm may produce better individualized dosages than some traditional methods of therapeutic drug monitoring. Since empirical evidence suggests that the linear model may adequately describe drugs and patient populations, and linear models are easier to handle than the nonlinear models traditionally used in population pharmacokinetics, our results highlight the potential applicability of linear mixed models to dosage computations and personalized medicine.

Lupus nephritis in Colombians: contrasts and comparisons with other populations.

Lupus nephritis (LN) is one of the most serious complications of systemic lupus erythematosus (SLE) since it is the major predictor of poor prognosis. The purpose of this study was to examine the clinical and immunological characteristics associated with LN development during the course of SLE in Colombians. Therefore, patients with SLE followed at five different referral centers in Medellin, Bogota, and Cali were included in this cross-sectional and multicenter study. Factors influencing LN were assessed by conditional logistic regression analysis, adjusting by gender, age at onset, duration of disease, and city of origin. The entire sample population included 467 patients, of whom 51% presented with LN. The presence of anti-dsDNA antibodies (adjusted odds ratio (AOR), 2.06; 95% confidence interval (CI), 1.16-3.65), pleuritis (AOR, 3.82; 95% CI, 1.38-10.54), and hypertension (AOR, 2.63; 95% CI, 1.23-5.62) were positively associated with LN, whereas the presence of anti-La antibodies was a protective factor against LN development (AOR, 0.4; 95% CI, 0.19-0.85). A review of literature on LN in different populations is made. The identified clinical- and laboratory-associated factors would assist earlier diagnosis and guide decisions on therapeutic interventions on this critical and frequent complication of SLE.

Association between smoking and alcohol use in the general population: stable and unstable odds ratios across two years in two different countries.

AIMS: The main objective of this article was to compare alcohol and tobacco consumption in the US and the Basque Country (the North of Spain) with particular attention to the association between alcohol and tobacco use. The consistency of findings was considered by analyzing data from two different years. These comparisons may provide a rational basis for exploring the associations between alcohol and cigarette use that are influenced by changes in use prevalences. METHODS: Two epidemiological samples from the US, obtained in 1992 and 1996, and two from the Basque Country, obtained in the same years, were used. Sampling methodologies were similar. Questionnaires were self-administrated with the help of interviewers, and were used to define ever smokers, ex-smokers, current smokers, heavy smokers, ever drinkers, ex-drinkers, current drinkers and weekly drinkers. The associations between smoking and alcohol drinking were explored through logistic regressions. RESULTS: The associations between current smoking and current drinking in the general population, and between ever smoking and weekly drinking among current drinkers appear very stable. In 1992 and 1996, US subjects who decided to try alcohol tended to try smoking and vice versa. In US Caucasians (particularly in 1996), heavy smoking was strongly associated with ever drinking among current smokers. In the Basque Country in 1992, there was a significant association between smoking cessation and drinking cessation among ever drinkers who also were ever smokers. CONCLUSIONS: Our analyses suggest that some associations between alcohol drinking and smoking behaviours are likely to be detected in Western countries where alcohol and nicotine are legal and easily available. On the other hand, other associations may be detected only in certain social contexts. These social contexts make the associations in subpopulations who are vulnerable to addiction, influence the results in the general population. In social contexts that exert considerable social pressure to quit smoking, such as in US Caucasians (particularly in 1996), heavy smoking was strongly associated with ever drinking among current smokers. When a social environment strongly discourages smoking and alcohol initiation (as in the US in 1992 and 1996), subjects who decide to try alcohol tend to try smoking and vice versa. The lack of social stigmatization of smoking and drinking in the Basque Country in 1992 may help to explain the significant association between smoking cessation and drinking cessation among ever drinkers who also were ever smokers.

Variables associated with alcohol, drug, and daily smoking cessation in patients with severe mental illnesses.

BACKGROUND: Co-occurrence of substance use disorders and severe mental illnesses (SMIs) is a major U.S. public health issue, although the role of tobacco is usually neglected. This study explored variables associated with alcohol, drug, and smoking cessation in a naturalistic setting. METHOD: Logistic regression was used to study variables associated with cessation of alcohol and drug use disorder and daily smoking in 560 SMI inpatients and outpatients from central Kentucky facilities. Patients with a lifetime history of alcohol or drug use disorder were considered to be in cessation if they had not suffered from abuse or dependence during the last year. Alcohol and drug use disorder diagnoses were determined using the Clinician Rating of Alcohol and Drug Use Disorder. Patients were recruited from July 2000 to March 2003. RESULTS: The cessation rates for alcohol and drug use disorders were, respectively, 44% (95% CI = 39% to 49%) and 46% (CI = 40% to 51%); these were higher than the daily cigarette smoking cessation rate of 10% (CI = 7% to 13%). Drug use disorders (p < or = .02), outpatient status (p < .001), and having a medical complication of obesity (diabetes mellitus, hypertension, or hyperlipidemia; p < .001) were significantly associated with alcohol cessation. Alcohol use disorder (p < .001), starting treatment with psychiatric medications after 33 years of age (p < .001), taking these medications for 14 years or more (p = .02), schizophrenia diagnosis (p < .001), outpatient status (p = .03), and obesity (p = .04) were significantly associated with drug cessation. Cessation of daily smoking was associated with hypertension (p = .02), late start of treatment with psychiatric medications (> 33 years old; p = .01), and lack of lifetime drug abuse (p < .001). CONCLUSIONS: These results are limited by the cross-sectional and naturalistic design but suggest that public health experts, researchers, and clinicians need to mindfully address smoking cessation in patients with SMIs. Clinicians may want to consider that medical illnesses may motivate patients with SMIs to stop substance abuse and that patients with SMIs who abuse both alcohol and drugs rarely stop abusing just one of them.