Ayala Cohen

LANGUAGE DEFICIT WITH ATTENTION-DEFICIT DISORDER : A PREVALENT COMORBIDITY

The aim of this study was to delineate the prevalence and behavioral patterns of children with attention-deficit and language problems as compared to children with attention-deficit hyperactivity disorder (ADHD) only Out of a cohort of 3208 children 6 to 11 years old, 5.2% were identified as having a primary ADHD. A teachers behavioral questionnaire, pediatric interview and assessment, IQ, attention tests, and language evaluation were employed. A 45% rate of language problems was identified. This comorbidity is more prevalent among girls (P = .02). Sequencing and short-term memory were significantly related to attention-deficit and language problems, but the attention scores were not. Language performance was the best predictor of group assignment and was superior to IQ in that regard. Correlation analysis revealed a different behavioral pattern for the two groups. It appears that a significant proportion of children with ADHD have a language comorbidity not reflected by IQ assessments; therefore, language tests should be considered as part of their routine assessment. Children with attention-deficit and language problems appear to have a different neurocognitive pattern underlying their problems as compared with their peers with ADHD only. (J Child Neurol 1998;13:493-497).

Comparing Regression Coefficients Across Subsamples

The comparison of regression coefficients across subsamples is relevant to many studies. Often, the same regression model is fitted to several subsamples and the question arises whether the effect of some of the explanatory variables, as expressed by the linear model, is the same for all subsamples. Because there are sometimes misunderstandings as to the statistical procedure which ought to be applied and consequently, wrong formulae are sometimes adopted by researchers. The purpose of this article is to describe in detail the relevant statistical procedures, together with the assumptions underlying the statistical tests. Some examples are quoted, in which wrong formulae were applied. It is demonstrated how the adoption of the wrong formulae might lead to mistaken conclusions.

Laparoscopic cholecystectomy for acute cholecystitis: can the need for conversion and the probability of complications be predicted? A prospective study.

AbstractBackground: Laparoscopic cholecystectomy (LC) in acute cholecystitis is associated with a relatively high rate of conversion to an open procedure as well as a high rate of complications. The aim of this study was to analyze prospectively whether the need to convert and the probability of complications is predictable. Methods: A total of 215 patients undergoing LC for acute cholecystitis were studied prospectively by analyzing the data accumulated in the process of investigation and treatment. Factors associated with conversion and complications were assessed to determine their predictive power. Results: Conversion was indicated in 44 patients (20.5%), and complications occurred in 36 patients (17%). Male gender and age >60 years were associated with conversion, but these factors had no sensitivity and no positive predictive value. The same factors, together with a disease duration of >96 h, a nonpalpable gallbladder, a white blood count (WBC) of >18,000/cc3, and advanced cholecystitis, predicted conversion with a sensitivity of 74%, a specificity of 86%, a positive predictive value of ∼40%, and a negative predictive value of 96%. However, these data became available only when LC was underway. Male gender and a temperature of >38°C were associated with complications, but these factors had no sensitivity and no positive predictive value. Progression along the stages of admission and therapy did not add predictive factors or improve the predictive characteristics. Male gender, abdominal scar, bilirubin >1 mg%, advanced cholecystitis, and conversion to open cholecystectomy were associated with infectious complications. Their sensitivity and positive predictive value remained 0 despite progression along the stages of admission and therapy. Conclusion: Although certain preoperative factors are associated with the need to convert a LC for acute cholecystitis, they have limited predictive power. Factors with higher predictive power are obtained only during LC. The need to convert can only be established during an attempt at LC. Preoperative and operative factors associated with total and infectious complications have no predictive power.

The impact of patient delay and physician delay on the outcome of laparoscopic cholecystectomy for acute cholecystitis

BACKGROUND Laparoscopic cholecystectomy is now used in the management of acute cholecystitis. Under these circumstances unfavorable conditions may result in conversion and complications. Information about these conditions may help in planning the laparoscopic approach or in proceeding directly to open cholecystectomy. This study was initiated to evaluate perioperative factors associated with conversion and complications of laparoscopic cholecystectomy in acute cholecystitis. Special attention was paid to the duration of complaints until surgery, to the delay on the part of the patient, and to the delay on the part of the physician. METHODS Between January 1994 and December 1997, we attempted to perform laparoscopic cholecystectomy on 348 patients with acute cholecystitis. All perioperative data were collected on standardized forms. RESULTS There were 182 cases (52%) of acute uncomplicated cholecystitis, 90 (26%) of gangrenous cholecystitis, 33 of hydrops (9.5%), and 43 of empyema of the gallbladder (12.5%). Seventy six patients (22%) needed conversion to open cholecystectomy and complications occurred in 57 cases. Advanced cholecystitis was associated with significant patient delay (P = 0.01), and it had a significantly higher conversion rate (39%) compared with early cholecystitis (14.5%); (P <0.00001). Conversion rates were also associated with male gender (P = 0.0017), a history of biliary disease (P = 0.0085), and a patient delay of >48 hours (P = 0.028). The total and infectious complication rates were associated with an age older than 60 years (P = 0.023 and 0.007, respectively) and male gender (P = 0.026 and 0.014, respectively). CONCLUSIONS In acute cholecystitis, patient delay is associated with a high conversion rate. Early timing of laparoscopic cholecystectomy tends to reduce the conversion rate, as well as the total and the infectious complication rates. Male gender, a history of biliary disease, and advanced cholecystitis are associated with conversion. Male and older patients are associated with a high total and infectious complication rates.

Detection of Subclinical Keratoconus Using an Automated Decision Tree Classification

PURPOSE To develop a method for automatizing the detection of subclinical keratoconus based on a tree classification. DESIGN Retrospective case-control study. METHODS setting: University Hospital of Bordeaux. participants: A total of 372 eyes of 197 patients were enrolled: 177 normal eyes of 95 subjects, 47 eyes of 47 patients with forme fruste keratoconus, and 148 eyes of 102 patients with keratoconus. observation procedure: All eyes were imaged with a dual Scheimpflug analyzer. Fifty-five parameters derived from anterior and posterior corneal measurements were analyzed for each eye and a machine learning algorithm, the classification and regression tree, was used to classify the eyes into the 3 above-mentioned conditions. main outcome measures: The performance of the machine learning algorithm for classifying eye conditions was evaluated, and the curvature, elevation, pachymetric, and wavefront parameters were analyzed in each group and compared. RESULTS The discriminating rules generated with the automated decision tree classifier allowed for discrimination between normal and keratoconus with 100% sensitivity and 99.5% specificity, and between normal and forme fruste keratoconus with 93.6% sensitivity and 97.2% specificity. The algorithm selected as the most discriminant variables parameters related to posterior surface asymmetry and thickness spatial distribution. CONCLUSION The machine learning classifier showed very good performance for discriminating between normal corneas and forme fruste keratoconus and provided a tool that is closer to an automated medical reasoning. This might help in the surgical decision before refractive surgery by providing a good sensitivity in detecting ectasia-susceptible corneas.

LTP-like changes induced by paired associative stimulation of the primary somatosensory cortex in humans : source analysis and associated changes in behaviour

Paired associative stimulation (PAS), which combines repetitive peripheral nerve stimulation with transcranial magnetic stimulation (TMS), may induce neuroplastic changes in somatosensory cortex (S1), possibly by long‐term potentiation‐like mechanisms. We used multichannel median nerve somatosensory evoked potential (MN‐SSEP) recordings and two‐point tactile discrimination testing to examine the location and behavioural significance of these changes. When TMS was applied to S1 near‐synchronously to an afferent signal containing mechanoreceptive information, MN‐SSEP changes (significant at 21–31 ms) could be explained by a change in a tangential source located in Brodmann area 3b, with their timing and polarity suggesting modification of upper cortical layers. PAS‐induced MN‐SSEP changes between 28 and 32 ms were linearly correlated with changes in tactile discrimination. Conversely, when the near‐synchronous afferent signal contained predominantly proprioceptive information, PAS‐induced MN‐SSEP changes (20–29 ms) were shifted medially, and tactile performance remained stable. With near‐synchronous mechanoreceptive stimulation subtle differences in the timing of the two interacting signals tended to influence the direction of tactile performance changes. PAS performed with TMS delivered asynchronously to the afferent pulse did not change MN‐SSEPs. Hebbian interaction of mechanoreceptive afferent signals with TMS‐evoked activity may modify synaptic efficacy in superficial cortical layers of Brodmann area 3b and is associated with timing‐dependent and qualitatively congruent behavioural changes.

Estimation of quantitative proteinuria by using the protein-creatinine ratio in random urine samples.

The protein-creatinine ratio was measured in urine samples obtained at three different times of the day and compared to the 24-hour protein excretion in 51 patients with a wide spectrum of renal function and proteinuria. A linear correlation, which was highly significant, was found between the two variables. The higher correlation was found in urine samples obtained at 08.00 and at 12.00 h and the lowest in samples obtained at 16.00 h. This correlation did not depend on the degree of proteinuria or on the sex of the patients, but was slightly dependent on the glomerular filtration rate. The protein-creatinine ratio was essentially identical with the 24-hour protein excretion. Thus, the normal range of proteinuria was represented by a ratio of less than 0.2, while nephrotic patients had a ratio above 3.5. We suggest that the protein-creatinine ratio in random urine samples could replace the timed collection methods at least for follow-up and screening.

Testing agreement for multi-item scales with the indicesrWG(J) and AD M(J)

The most popular index of agreement has been rWG(J); more recently, the ADM(J) index also has been used. This study addresses two problems: first, how to test the statistical significance of rWG(J) and ADM(J) and, second, how to infer from the indices that were evaluated for each group about the agreement of the ensemble of groups. The authors extend the inference based on either rWG(J) or ADM(J) by focusing on multiple-item scales and on the whole ensemble of groups. Their method is based on simulations, as was done by Dunlap, Burke, and Smith-Crowe (2003) and by Cohen, Doveh, and Eick (2001). The tests are illustrated on the data of Bliese, Halverson, and Schriesheim (2002) pertaining to a sample of 2,042 U.S Army soldiers in 49 U.S. Army companies. Software for our procedures is available both as a SAS code and in the Multilevel Modeling in R package (Bliese, 2006).

Promoting a biopsychosocial orientation in family practice: effect of two teaching programs on the knowledge and attitudes of practising primary care physicians

The bio-psychosocial (BPS) approach to patient care has gained acceptance in medical education. However, reported teaching programs rarely describe the efficacy of alternative approaches to continuing medical education aimed at promoting a BPS approach. The objective was to describe and evaluate the effect of two teaching programs on learners’ BPS knowledge, management intentions, patient-centered attitudes, professional self-esteem, burnout, work related strain and mental workload. The learners were Israeli general practitioners. The first (“didactic”) program consisted of problem-based reading assignments, lectures and discussions. The second (“interactive”) program consisted of reading assignments, lectures and discussions, in addition to role-playing exercises, Balint groups and one-to-one counseling by a facilitator. One month before and six months after the teaching interventions, we used structured questionnaires to test for knowledge, management intentions (responses to questions, such as “what would you tell a patient with …”) and attitudes. Both programs led to measurable improvement in knowledge, intentions, patient-centered attitudes and self-esteem. The interactive teaching approach improved significantly more the learners’ professional self-esteem and intentions than the didactic approach. Self-reported burnout significantly increased after the program. It is concluded that teaching intervention enhanced a BPS orientation and led to changes in knowledge, intentions, self-esteem and attitudes. An interactive method of instruction was more effective in achieving some of these objectives than a didactic one. The observed increase in burnout was unexpected and requires further study and confirmation.

Effect of a biopsychosocial approach on patient satisfaction and patterns of care

AbstractBACKGROUND: There is a growing tendency to include in medical curricula teaching programs that promote a biopsychosocial (BPS) approach to patient care. However, we know of no attempts to assess their effect on patterns of care and health care expenditures. OBJECTIVE: To determine whether 1) a teaching intervention aiming to promote a BPS approach to care affects the duration of the doctor-patient encounter, health expenditures, and patient satisfaction with care, and 2) the teaching method employed affects these outcomes. METHODS: We compared two teaching methods. The first one (didactic) consisted of reading assignments, lectures, and group discussions. The second (interactive) consisted of reading assignments, small group discussions, Balint groups, and role-playing exercises. We videotaped patient encounters 1 month before and 6 months after the teaching interventions, and recorded the duration of the videotaped encounters and whether the doctor had prescribed medications, ordered tests, and referred the patient to consultants. Patient satisfaction was measured by a structured questionnaire. RESULTS: Both teaching interventions were followed by a reduction in medications prescribed and by improved patient satisfaction. Compared to the didactic group, the interactive group prescribed even fewer medications, ordered fewer laboratory examinations, and elicited higher scores of patient satisfaction. The average duration of the encounters after the didactic and interactive teaching interventions was longer than that before by 36 and 42 seconds, respectively. CONCLUSIONS: A BPS teaching intervention may reduce health care expenditures and enhance patients’ satisfaction, without changing markedly the duration of the encounter. An interactive method of instruction was more effective in achieving these objectives than a didactic one.