Working in old age in Mexico: Implications for Cognitive Functioning

Previous studies indicate that occupation might affect cognitive functioning in late life. As people in low and middle income countries often have to work until late life, we sought to investigate if there are cognitive benefits to working later into life and whether cognitive function deteriorates after exiting the labor force. We analyzed longitudinal data from the Mexican Health and Aging Study (MHAS), a nationally representative sample of Mexican adults age 50+ (n=7,375), that assessed cognitive functioning by verbal learning, delayed recall, and visual scanning. Analyses were carried out using mixed-effects modeling corrected for the influence of gender, IADLs, diabetes, stroke, hypertension, depression, income, and marital status. Results suggest that working actively, compared to exiting the workforce, was associated with cognitive performance only in context with occupation. Domestic workers had a faster decline in verbal learning (b=-0.02, p=0.020) and delayed recall (b=-0.02, p=0.036) if they continued working actively and people working in administration (b=0.03, p=0.007), sales (b=0.02, p=0.044), and educators (b=0.03, p=0.049) had a slower decline in visual scanning if they continued working in old age. Our findings indicate that continued participation in the labor force in old age does not necessarily come with cognitive benefits. Whether or not working actively in later life protects or even harms cognitive functioning is likely to depend on the type of job.

Weighted nearest neighbours-based control group selection method for observational studies

Although in observational studies, propensity score matching is the most widely used balancing method, it has received much criticism. The main drawback of this method is that the individuals of the case and control groups are paired in the compressed one-dimensional space of propensity scores. In this paper, such a novel multivariate weighted k-nearest neighbours-based control group selection method is proposed which can eliminate this disadvantage of propensity score matching. The proposed method pairs the elements of the case and control groups in the original vector space of the covariates and the dissimilarities of the individuals are calculated as the weighted distances of the subjects. The weight factors are calculated from a logistic regression model fitted on the status of treatment assignment. The efficiency of the proposed method was evaluated by Monte Carlo simulations on different datasets. Experimental results show that the proposed Weighted Nearest Neighbours Control Group Selection with Error Minimization method is able to select a more balanced control group than the most widely applied greedy form of the propensity score matching method, especially for individuals characterized with few descriptive features.

The influence of caregivers and behavioral and psychological symptoms on nursing home placement of persons with Alzheimer's disease: A matched case-control study

OBJECTIVES

Behavioral and psychological symptoms of dementia in individuals with Alzheimer's disease and caregiver characteristics may influence the decision to provide care at home or in a nursing home, though few studies examine this association near the actual time of nursing home placement. Using a matched case-control design, this study investigates the association between (1) total Neuropsychiatric Inventory score, (2) the Neuropsychiatric Inventory-4 (an agitation/aggression subscale), and (3) individual domains of the Neuropsychiatric Inventory and nursing home placement.

METHODS

Data from the South Carolina Alzheimer's disease Registry provides an opportunity to expand the literature by looking at cases at the time of nursing home care eligibility/placement and allowing for propensity-score-matched controls. Cases (n = 352) entered a nursing home within 6 months of study initiation; controls (n = 289) remained in the community. Registry data were combined with caregiver survey data, including the Neuropsychiatric Inventory. Conditional logistic regression was applied.

RESULTS

A 10% increase in the Neuropsychiatric Inventory score implied a 30% increase in odds of nursing home admission (odds ratio: 1.30; 95% confidence interval: 1.14-1.50), having married or male caregivers predicted nursing home placement. Cases versus controls were significantly more likely to have behavioral and psychological symptoms of dementia related to agitation/aggression 1 month prior to nursing home admission.

CONCLUSION

Interventions targeting behavioral and psychological symptoms of dementia without available effective interventions in individuals with Alzheimer's disease and caregiver support services are necessary to prevent or delay nursing home admission.

A combined smoking cessation intervention within a lung cancer screening trial: a pilot observational study

AIMS AND BACKGROUND

The time of lung cancer screening may provide the ideal setting to discuss and initiate a smoking cessation plan that includes pharmacologic aids. No studies to date have fully investigated the potential effectiveness of such combined approach.

METHODS

We prospectively evaluated the biochemically verified 1-year continuous abstinence rate from smoking of 187 persistent smokers enrolled within the Multicentric Italian Lung Detection Trial (MILD), who received a pharmacologic aid to quit smoking with varenicline along with behavioral counseling. The propensity of study subjects to succeed in smoking cessation was also monitored.

RESULTS

At 12 months, the continuous abstinence rate from smoking was achieved in 37 out of 187 patients (19.8%), with a propensity to succeed in smoking cessation for the assisted attempt equal to 1.43, as compared to an unassisted MILD patient. At the end of the third month of therapy, 48.7% of subjects showed a continuous abstinence rate, while only 33.7% of patients were abstinent from smoking at 6 months. At baseline, the subgroup of MILD participants who were originally allocated to lung tomography showed higher smoking intensity than those allocated to no screening.

CONCLUSIONS

A combined smoking cessation intervention can be implemented with satisfactory results within a lung cancer screening program; this preliminary observation needs to be replicated in a prospective investigation. Clinicians should consider that lung cancer screening may be falsely reassuring for persistent smokers; therefore it should always be coupled with a smoking cessation program.

Predictors of success in smoking cessation among Italian adults motivated to quit

We examined the role of sexual gender, age, working status, education, cigarettes per day, Fagerström test, age of onset, pharmacologic intervention (bupropion or varenicline), 10 sessions of cognitive-behavioral group counseling therapy (GCT) conducted over 6 weeks, and level of attendance of the counseling program as predictors of smoking cessation on 1282 Italian adult smokers. Results of a multi-variate forward stepwise conditional logistic analysis, at the first step, indicate that subjects who attended the program from 4 to 6 sessions and from 1 to 3 sessions, respectively, resulted about 3 times and 24 times more likely to smoke than those attending from 7 to 10 sessions; at the second step, subjects with high Fagerström score were 2 times more likely to smoke than subjects with low/middle Fagerström; at the third step, subjects treated only with GCT were 2 times more likely to smoke than subjects with combined pharmacologic interventions and GCT; at the fourth step, subjects with age of onset less than 17 years were 1.5 times more likely to smoke than subjects with a higher age of onset; eventually, at the fifth step women resulted 1.5 times more likely to smoke than men. In conclusion, we found that a steady attendance of the cognitive behavioral program, as well as the addition of pharmacologic interventions to counseling, remarkably increased the probability of the smoking cessation behavior to be determined. Nevertheless, FTQ was a valid measure in predicting the smoking cessation, and women revealed to be more likely to keep the smoking behavior, as well as subjects who declared an age of onset less than 17 years.

Cigarette smoking knowledge and perceptions among students in four Italian medical schools

INTRODUCTION

Tobacco smoking is the leading cause of premature death in the developed world. Advice and assistance by physicians help smokers quit, but little attention has been paid to the topic of tobacco dependence in the curricula of Italian medical schools. Consequently, few physicians follow the clinical practice guidelines for treating dependence.

METHODS

This study was conducted on 439 students at 4 Italian medical schools in 2010. Students were asked to complete a 60-item questionnaire. Two scores were computed: Score 1 assessed knowledge of the epidemiology of smoking, risks associated with smoking, and benefits of cessation. Score 2 assessed knowledge of tobacco dependence treatment guidelines and the effectiveness of treatments. A score of less than 60% indicated insufficient knowledge.

RESULTS

Medical students had limited knowledge of the epidemiology of smoking, attributable morbidity and mortality, and the benefits of cessation. This limited knowledge was reflected by the finding that 70% of students had a total Score 1 less than 60% of available points. Knowledge of clinical guidelines, perceived competence in counseling smokers, and treatment of addiction was also insufficient, as 76% of students achieved a total Score 2 of less than 60%.

CONCLUSIONS

Our data demonstrate that Italian medical students have limited knowledge about tobacco dependence, how to treat it, and the critical role of the physician in promoting cessation. Taken together with research from other countries, these findings suggest that medical schools do not offer adequate training in tobacco dependence and provide a rationale for modifying the core curriculum to include more information on tobacco dependence treatment.

Evaluation of the comparative analgesic effectiveness of transdermal and oral opioids in cancer patients: a propensity score analysis

BACKGROUND

Transdermal delivery systems containing fentanyl or buprenorphine, despite the relatively lack of comparative studies, have reached an impressive share of the market in several countries. In the context of a wider observational study, we applied the propensity score to test the comparative effectiveness of the two routes of administration (oral vs. transdermal).

METHODS

We applied the propensity score in a subgroup of patients (starting the World Health Organization third step therapy during the scheduled follow-up of 28 days) using pre-planned primary (pain intensity change) and secondary endpoints, such as increase in doses, need for switching and safety profile. Univariate and multivariate analyses were carried out.

RESULTS

Three-hundred sixty-six eligible cases were analysed. We found a difference among the two groups in terms of variables potentially associated with therapy choice and outcomes. After adjusting for propensity score, results were in favour of transdermal delivery systems for the primary endpoint (odds ratio 1.68; p = 0.04). A similar trend was also present for the other secondary endpoints. Only in the case of nausea and vomiting, patients receiving transdermal delivery systems reported a higher frequency of events.

CONCLUSION

The application of the propensity score has helped understand better the actual effectiveness of transdermal delivery systems that are at least equivalent to the oral opioids, and even more effective for pain intensity reduction.

Venesection for non-alcoholic fatty liver disease unresponsive to lifestyle counselling--a propensity score-adjusted observational study

BACKGROUND/AIM

To test the short-term clinical usefulness of venesection associated with lifestyle counselling as against counselling alone on insulin resistance and liver enzymes in subjects with non-alcoholic fatty liver disease (NAFLD), using a propensity score approach.

METHODS

We carried out a 6- to 8-month observational analysis of 198 NAFLD patients in three Italian referral centres (79 venesection and 119 counselling alone). Insulin resistance was measured by the homeostasis model assessment (HOMA) method. Logistic regression was used to identify factors associated with normal HOMA and normal alanine aminotransferase (ALT) at the end of observation. The results were adjusted for the propensity score to be enrolled in the venesection programme, based on clinical and laboratory data, including common HFE polymorphisms and liver biopsy (available in 161 cases).

RESULTS

After adjustment for propensity and changes in BMI, venesection was significantly associated with normal HOMA [all cases: odds ratio (OR) 3.00; 95% confidence interval (CI) 1.51-5.97; cases with histology: OR 2.29; 95% CI 1.08-4.87] and ALT within normal limits (all cases: OR 2.56; 95% CI 1.29-5.10; cases with histology: OR 2.81; 95% CI 1.20-5.24). The results were confirmed in an analysis of 57 pairs matched for propensity, where venesection similarly increased the probability of normal HOMA (OR 3.27; 95% CI 1.16-7.84) and normal ALT (OR 5.60; 95% CI 2.09-15.00). Similar data were obtained in the subset of cases with normal basal ferritin (<350 ng/ml).

CONCLUSION

Iron depletion by venesection favours the normalization of insulin resistance and raised liver enzymes in non-haemochromatosis patients with NAFLD.

Propensity score estimation: neural networks, support vector machines, decision trees (CART), and meta-classifiers as alternatives to logistic regression

OBJECTIVE

Propensity scores for the analysis of observational data are typically estimated using logistic regression. Our objective in this review was to assess machine learning alternatives to logistic regression, which may accomplish the same goals but with fewer assumptions or greater accuracy.

STUDY DESIGN AND SETTING

We identified alternative methods for propensity score estimation and/or classification from the public health, biostatistics, discrete mathematics, and computer science literature, and evaluated these algorithms for applicability to the problem of propensity score estimation, potential advantages over logistic regression, and ease of use.

RESULTS

We identified four techniques as alternatives to logistic regression: neural networks, support vector machines, decision trees (classification and regression trees [CART]), and meta-classifiers (in particular, boosting).

CONCLUSION

Although the assumptions of logistic regression are well understood, those assumptions are frequently ignored. All four alternatives have advantages and disadvantages compared with logistic regression. Boosting (meta-classifiers) and, to a lesser extent, decision trees (particularly CART), appear to be most promising for use in the context of propensity score analysis, but extensive simulation studies are needed to establish their utility in practice.

A smoking ban in public places increases the efficacy of bupropion and counseling on cessation outcomes at 1 year

INTRODUCTION

Legal restrictions have contributed to the decline in smoking prevalence in several European countries. We investigated the impact of the Italian 2005 indoor smoking ban on the efficacy of counseling alone or in combination with bupropion for smoking cessation.

METHODS

Before and after the introduction of the ban (2001-2006), 550 smokers were enrolled in the smoking cessation program in Rome and were asked to choose between a 6-week group counseling therapy (GCT) given alone or in combination with 7 weeks of daily bupropion. Follow-up was completed 12, 26, and 52 weeks after the quit day. Due to the observational nature of the study, we used propensity scores to match 138 and 290 subjects (pre-/postban) in the bupropion- and GCT-only groups, respectively.

RESULTS

Covariate balance in the two matched samples was adequate for all variables except "coffee consumption" in the GCT-only group. The regression adjusted odds ratios indicated that the introduction of the ban resulted in 52% reduced odds of continued smoking at 12 months among the GCT + bupropion group and 41% reduced odds in the GCT-only group. We observed that the ban was associated with both increased 12-month abstinence rates and motivation to quit. In a mediation analysis, we determined that the total effect of the smoking ban on the abstinence rate was reduced after controlling for motivation, which confirmed that motivation was a partial mediator.

DISCUSSION

The introduction of an indoor smoking ban improved the efficacy of smoking cessation treatments by possibly providing a setting that increased the level of motivation to stop smoking.

Early versus late intravenous insulin administration in critically ill patients

OBJECTIVE

To investigate whether timing of intensive insulin therapy (IIT) after intensive care unit (ICU) admission influences outcome.

DESIGN AND SETTING

Single-center prospective cohort study in the 14-bed medical ICU of a 1,171-bed tertiary teaching hospital.

PATIENTS

The study included 127 patients started on ITT within 48 h of ICU admission (early group) and 51 started on ITT thereafter (late group); the groups did not differ in age, gender, race, BMI, APACHE III, ICU steroid use, admission diagnosis, or underlying comorbidities.

MEASUREMENTS AND RESULTS

The early group had more ventilator-free days in the first 28 days after ICU admission (median 12 days, IQR 0-24, vs. 1 day, 0-11), shorter ICU stay (6 days, IQR 3-11, vs. 11 days, vs. 7-17), shorter hospital stay (15 days, IQR 9-30, vs. 25 days, 13-43), lower ICU mortality (OR 0.48), and lower hospital mortality (OR 0.27). On multivariate analysis, early therapy was still associated with decreased hospital mortality (ORadj 0.29). The strength and direction of association favoring early IIT was consistent after propensity score modeling regardless of method used for analysis.

CONCLUSIONS

Early IIT was associated with better outcomes. Our results raise questions about the assumption that delayed administration of IIT has the same benefit as early therapy. A randomized study is needed to determine the optimal timing of therapy.