Impact of Select Geometric and Operational Parameters on Hydrodynamics in Dissolution Apparatus 2 (Paddle Apparatus): A Design of Experiments Analysis Based on Computational Fluid Dynamics Simulations.

PURPOSE: A Design of Experiments (DOE) analysis driven by Computational Fluid Dynamics (CFD) simulations was used to evaluate individual and two-factor interaction effects of varying select geometric and operational parameters on the hydrodynamics in dissolution apparatus 2 (paddle apparatus). METHODS: Simulations were run with meshing controls and solution strategies retained from a mesh-independent validated baseline model. Distance between vessel and impeller bottom surfaces, impeller offset, vessel radius and impeller rotation speed were considered as input parameters. The velocity magnitudes at four locations near the vessel bottom surface were considered as output parameters. Response surfaces and Pareto charts were generated to understand individual and two-factor interaction effects of input parameters on the output parameters. RESULTS: Impeller offset has a dominating influence of a linear and quadratic nature on the output parameters and affects overall hydrodynamics. Changes to other input parameters have limited influence on velocity magnitudes at locations closest to the vessel axis and on overall hydrodynamics. However, these parameters have important influences of varying degrees on velocity magnitudes at locations away from the vessel axis. CONCLUSIONS: The hydrodynamics in Apparatus 2 is influenced differently by different parameters and their combinations. Impeller offset has a stronger influence when compared to parameters that do not alter apparatus symmetry.

Survey of peptide quantification methods and comparison of their reproducibility: A case study using oxytocin.

USP's peptide reference standards content is typically determined using an HPLC assay against an external standard for which the purity was determined by a mass balance approach. To explore the use of other analytical methods, the USP Biologics Department conducted a multi-laboratory collaborative study. The study determined the inter-laboratory variability for peptide quantitation using the following methods: HPLC assay, quantitative nuclear magnetic resonance (qNMR) spectroscopy, or amino acid analysis (AAA). The three methods were compared with regard to their suitability for quantitation of the nonapeptide oxytocin. In this study, the HPLC assay method using the same peptide bulk material as the standard showed the lowest inter-lab variability. The coefficient of variation (%CV) was calculated without counting the uncertainty associated with the purity assignment of the standard with mass balance. The proton qNMR method is a direct measurement of the peptide against an internal standard, which is not difficult to perform under common laboratory conditions. Because of the simpler operation and shorter analytical time, qNMR as a primary method for peptide reference standard value assignment deserves further exploration.

An investigation of self-assessment bias in mental health providers.

Previous research has consistently found self-assessment bias (an overly positive assessment of personal performance) to be present in a wide variety of work situations. The present investigation extended this area of research with a multi-disciplinary sample of mental health professionals. Respondents were asked to: (a) compare their own overall clinical skills and performance to others in their profession, and (b) indicate the percentage of their clients who improved, remained the same, or deteriorated as a result of treatment with them. Results indicated that 25% of mental health professionals viewed their skill to be at the 90th percentile when compared to their peers, and none viewed themselves as below average. Further, when compared to the published literature, clinicians tended to overestimate their rates of client improvement and underestimate their rates of client deterioration. The implications of this self-assessment bias for improvement of psychotherapy outcomes are discussed.

Reducing MMPI-defensiveness in professionals presenting for evaluation.

Due to the possibility of negatively impacting their license to practice, professionals presenting for an intensive fitness for duty multidisciplinary evaluation might have a motivation to minimize emotional difficulties in a psychological evaluation. This study examines the incidence of "fake-good" Minnesota Multiphasic Personality Inventory-2 (MMPI-2) profiles in those being evaluated and changes in psychometric test scores when extremely defensive patients are asked to repeat the testing with specialized instructions. As part of the evaluation process, patients completed an MMPI-2, as well as other psychometric instruments. The validity of each MMPI-2 profile was evaluated. Patients who produced an invalid test profile due to hyperdefensiveness were provided feedback on their defensiveness and asked to be more open and honest in a repeat testing. More than half (59%) of the patients produced invalid test profiles. Being given feedback and a request for openness and honesty resulted in 90% of valid profiles in the repeat testing. On the second testing, there were significant differences on 6 of the 13 MMPI-2 scales, as well as on each of the separate measures of depression, anxiety, and anger. It appears to be important to include a psychometric measure that includes a validity scale in the evaluation process of professionals because the majority produced invalid MMPI-2 profiles. It is recommended that patients who are defensive in their testing be asked to repeat the test battery to gain a more accurate clinical picture of the individual professional.

Psychological correlates of laparoscopic adjustable gastric band and gastric bypass patients.

BACKGROUND: To compare psychological characteristics of patients seeking laparoscopic adjustable gastric band (LAGB) and gastric bypass surgery. METHODS: In the present study, 898 women were assessed as part of a comprehensive presurgical evaluation. Of these 898 patients, 107 (12%) were seeking LAGB surgery and 791 (88%) were seeking gastric bypass surgery. Their scores on a battery of psychological tests were compared with T-tests with Bonferroni correction. RESULTS: Those patients seeking gastric bypass had greater body mass indices than those seeking LAGB. However, the analyses found no statistically significant differences on measures of IQ, depression, anxiety, anger, self-assessed reasons for weight gain, and psychopathology and personality as indicated by Minnesota Multiphasic Personality Inventory-2 scale scores. CONCLUSIONS: The psychological evaluation can be helpful in identifying behavioral and emotional issues that merit adjunct psychological attention to optimize long-term surgical outcome. These results suggest that, as a group, no differential treatment planning needs to take place for psychological issues based on surgery performed.

Limitations of the Millon Behavioral Medicine Diagnostic (MBMD) with bariatric surgical candidates.

BACKGROUND: In this paper, we critique the Millon Behavioral Medicine Diagnostic's (MBMD) psychometric characteristics for use with bariatric surgery patients. METHODS: The reliability data presented by the test authors in their manual were examined. RESULTS: The results found 16 of 32 scales of have internal consistency reliability coefficients that do not meet minimal standards for use with bariatric populations. Of the remaining 16 scales, 13 do not have any compelling evidence that they are reliable. We suggest that if a test is not psychometrically reliable then its validity is called into question. Based on these data, 16 of the MBMD's 32 scales have inadequate reliability and 13 are lacking evidence of reliability. We urge clinicians to carefully consider these findings and the implications for their work with bariatric surgery patients.

MMPI-2 profiles of bariatric surgery patients: a replication and extension.

BACKGROUND: Maddi et al. (Obes Surg, 7:397-404, 1997) reported significant elevations on several MMPI-2 scales in a morbidly obese population. Since the number of patients presenting for bariatric surgery has increased significantly in the decade since this study, we replicated the original Maddi et al. study to investigate if there have been any appreciable changes in these patients' psychological profiles within the past 10 years. METHODS: First, we replicated the original Maddi et al. study using the same definition of profile elevations used by these investigators. Second, we extended these findings to include a fourth classification of extremely elevated profiles. Finally, we included several measures of different emotional states/characteristics in an attempt to further delineate what these elevated profiles may actually represent. RESULTS: Our findings generally support the results of the original Maddi et al. study. Additionally, a number of significant relationships were found between our additional measures and MMPI-2 elevations. CONCLUSIONS: Many morbidly obese patients presenting for bariatric surgery have elevated MMPI-2 profiles, some of which would be considered "invalid" profiles. We recommend procedures for obtaining more valid profiles from such patients. We also urge the use of other measures in addition to the MMPI-2 to more specifically clarify the personality traits/characteristics in these patients.

Reading level of Overeaters Anonymous primary educational material.

Educational materials are often a key component of recovery in a mutual-help group. However, in order to be helpful to a maximum number of members, these materials must be presented at a reading level that is comprehensible. Two measures of readability, The Flesch Reading Ease score and the Flesch-Kincaid Grade-Level score were applied to 20 random paragraphs chosen from The Twelve Steps and Twelve Traditions of Overeaters Anonymous. Results indicate that the average paragraph is written just below the tenth grade level and close to an optimum level of reading ease. However, due to variability, almost half (45%) of the paragraphs fell in the category of Difficult Reading Ease and half were found to be at a tenth grade reading level or beyond. In order to maximize the utility of this educational text, it is recommended that future editions take into consideration principles of readability.

Psychological evaluation of bariatric surgery applicants: procedures and reasons for delay or denial of surgery.

BACKGROUND: Psychologists play an important role as members of the bariatric surgery team. The current investigation examined the frequency with which psychologists recommend delay or denial of surgery for psychological reasons, the procedures they use in making their clinical decisions, and the reasons for such conclusions. METHOD: A sample of 103 psychologists with experience in conducting pre-surgical psychological evaluations responded to a brief survey. RESULTS: There was significant variability in the number of evaluations psychologists complete and the instruments they use to make their clinical decisions. For most candidates, the evaluation results in psychological clearance for surgery. However, approximately 15%, on average, are delayed or denied for psychological reasons. The most common reasons for delaying or denying surgery were significant psychopathology (including psychosis or bipolar disorder), untreated or undertreated depression, and lack of understanding about the risks and postoperative requirements of surgery, which were reported by 51, 39, and 30% of respondents, respectively. Several other reasons were reported less frequently and many appeared to be idiosyncratic. CONCLUSION: Psychologists differ in their preoperative evaluation practices. Further research is needed to determine the reasons for the variability in clinical decision making and the long-term medical and psychosocial outcomes associated with the recommendation to delay or deny surgery for psychosocial reasons. When patients receive such a recommendation, they can be encouraged to seek a second opinion from a mental health professional with bariatric expertise.

Reducing Minnesota Multiphasic Personality Inventory defensiveness: effect of specialized instructions on retest validity in a sample of preoperative bariatric patients.

BACKGROUND: Because of the possibility of being denied or delayed surgery, bariatric patients might have a motivation to minimize any emotional difficulties in the preoperative psychological evaluation. This study examined changes in the psychometric test scores when extremely defensive patients were asked to repeat the testing. METHODS: Changes in the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) scale scores were studied in a subsample of patients referred to the author for a preoperative psychological evaluation. After producing defensive MMPI-2 test profiles, these bariatric patients (n = 31) were provided feedback on their defensiveness and asked to be more open and honest on the repeat testing. RESULTS: The vast majority (94%) of the patients produced valid profiles on the second test. On the second test, significant differences were found on 6 of the 13 MMPI-2 scales, as well as on separate measures of depression, anxiety, and anger. CONCLUSION: It appears to be important to include a psychometric measure that includes a validity scale in the evaluation process, because patients might be motivated to present in a defensive or overly virtuous light in fear that a negative evaluation from the psychologist would adversely affect a decision regarding their candidacy for surgery. It is recommended that patients who are defensive in their testing be asked to repeat the test battery.

Readability level of health insurance portability and accountability act notices of privacy practices utilized by academic medical centers.

Recently enacted Health Insurance Portability and Accountability Act legislation requires health care professionals to provide patients with a "Notice of Privacy Practices" (NPP) document as part of their informed consent process to participate in assessment and treatment. We were interested in the readability of these forms. We attempted to find a NPP from an academic medical center in each state plus the District of Columbia where documents were placed on the institution's Web site. Documents were obtained from 40 jurisdictions and were then analyzed utilizing two measures of readability. The majority (65%) of these documents were written beyond the 12th grade reading level, and almost the entire sample (90%) fell in the difficult range of reading ease. Academic medical centers have an ethical obligation to improve the readability of these documents and should do so to improve clinical practice and reduce liability.

Self-assessed emotional factors contributing to increased weight gain in pre-surgical bariatric patients.

BACKGROUND: One important part of the pre-surgical mental health evaluation is to assess what, if any, emotional factors may be related to a patient's eating behavior. In this way, appropriate biopsychosocial interventions may be designed to facilitate their long-term maintenance of weight loss. The current investigation examined the role that negative emotional states might play in increased pre-surgical eating behavior in a sample of bariatric surgery patients. METHODS: A sample of 122 female patients completed the Weight and Lifestyle Inventory as a component of a comprehensive psychological evaluation. This questionnaire contains 6 items that assess the degree of 6 negative emotional states. These data were examined to determine which negative emotional states were most frequently related to increased eating behavior. In addition, the frequency of reporting multiple emotional contributors to eating was also examined. RESULTS: Eating when stressed received the highest scores, followed by eating when bored, eating when depressed, eating when anxious, eating when angry, and eating when tired. A large segment (38%) of the sample indicated that emotional factors did not contribute a large amount to their increased weight gain, while on the other hand, a large segment (40%) could be identified as "emotional eaters." CONCLUSION: To increase the likelihood of long-term maintenance of weight loss, a significant portion of this patient population would benefit from interventions targeting overcoming boredom, reducing stress, and managing depression. In the pre-surgical evaluation, it is important to identify those patients who are "emotional eaters" and to refer them for appropriate interventions.

Survival strategies in community mental health: a study of management consensus.

Human service agency and program managers were surveyed on survival strategies in the face of shrinking government funding. The two groups ranked strategies in order of importance and researchers compared results. There was strong general agreement between the two groups, suggesting that top and middle management are working ideologically and practically along the same lines.