The use of parametric vs. nonparametric tests in the statistical evaluation of rating scales

In psychiatric studies, treatment efficacy is usually measured by rating scales. These scales have ordinal (rank) level and the statistical evaluation of the scale scores should be performed with nonparametric rather than parametric tests. In recent years, nonparametric statistical procedures for repeated measures have been developed for the evaluation of clinical trials in psychiatry. To assess the frequency of application of nonparametric tests in psychiatric trials, an analysis was performed on all treatment studies with panic disorder patients (DSM-III/III-R) that could be traced in the literature. This survey revealed that nonparametric tests were used in only 16.7% of all studies.     

Preoperative evaluation and postoperative care of the elderly patient undergoing major surgery

As the population ages and as surgical and anesthetic techniques advance, more and more elderly patients are referred for surgery. As a result, the physician must be increasingly aware of the aged response to surgery and the management of the geriatric surgical patient in the perioperative period. Elderly patients are prone to cardiac, respiratory, and infectious complications, and thus, they need to be screened for the presence of pre-existing disease. In addition, the geriatric patient needs to be carefully monitored in the proper postoperative environment to guard against untoward sequelae.     

The evaluation of intervention programmes for communicatively impaired elderly people

A study is described which examined the efficacy of group intervention programmes using trained volunteers as agents of intervention with elderly nursing home residents with communication impairments. A series of intervention programmes, which consisted of six weekly sessions, was designed. Sessions were a combination of information giving, discussion and practical components where residents could practise newly acquired skills. Sessions covered a number of core components--the communication process, comprehension, expression and pragmatics, as well as information that was specific to the communication impairment. Volunteers were trained to administer the programme. Four groups of communicatively impaired elderly people were included in the study--a group of hearing-impaired residents, those with communication impairment subsequent to Parkinson's disease, those with communication impairment subsequent to cerebrovascular accident and those in varying stages of dementia. Results indicated that, although the residents studied responded very individually to the intervention strategies, with several subjects failing to demonstrate any gains in communicative competence from pre- to post-intervention, positive gains in communication skills and self-management of communicative impairment were observed for a number of subjects. Complicating factors such as general health and well-being are considered as uncontrollable variables in the measurement of performance in the elderly.     

Paraesophageal hernias in elderly patients. An indication for laparoscopic surgery

Paraesophageal hernias are uncommon conditions which appear mainly in elderly people, frequently associated with sliding hernias or gastric volvulus. Considered a high risk pathology, surgical management is preferred to avoid serious complications. Due to advanced age and operative risks, a laparoscopic approach was performed in the three patients with paraesophageal hernia. In mixed hernias, a Nissen or Toupet fundoplication and closure of the hiatal defect was carried out. In a case with gastric rotation, reduction of the herniated stomach and posterior partial fundoplication with gastropexy was performed. No postoperative complications occurred and recovery was satisfactory. Laparoscopic management seems to be a good choice for elective treatment of paraesophageal hernias in elderly patients.     

Cancer surgery in the elderly

Cancer surgery is safe for older patients and should not be denied on the basis of chronological age. The curability of cancer in the elderly is predicated on the individual's tolerance of major surgery. We present the physiologic changes that occur with aging and focus on their influence upon surgical decision making, the risk factors associated with cancer surgery in the elderly, the preoperative assessment, and perioperative care of the elderly cancer patient, as well as surgical considerations for specific neoplasms.     

Heart surgery in the elderly

The number of octogenarian patients undergoing an open heart procedure in our unit is the fastest increasing group of patients. Between June 1985 and July 1994 112 octogenarians (mean age 81.7 years, 60 males, 52 females) underwent cardiac operations. The postoperative course was uneventful in 90 patients (80.4%). The perioperative mortality rate was 8.9% (10 patients). Mortality was lowest in the group receiving aortic valve replacement, with one death out of 30 patients (3.3%). The cause of death was left- or biventricular heart failure in more than half of the fatalities. Postoperative complications included: AV-block III (n = 1), postoperative bleeding (n = 2), unstable sternum (n = 3), acute cholecystitis (n = 1), low cardiac output syndrome (n = 1), stroke (n = 1), pneumothorax (n = 2) and urinary tract infections (n = 1). We consider open heart procedures in octogenarians, despite a mortality rate of 8.9%, as justified. According to the severity and course of clinical symptoms and the type of surgery required, selection of patients for operation should be decided on at an early stage of the disease. Not only life expectancy increases, but there is also a significant increase in life quality for these patients.     

Classification of depressive disorders in the DSM-V: Proposal for a two-dimension system.

The number of categories and specifiers for mood disorders has increased with each successive edition of the Diagnostic and Statistical Manual for Mental Disorders (DSM). Many of these categories and specifiers can be viewed as an effort to map the various permutations of severity and chronicity that characterize the depressive disorders. However, this has resulted in a system that (a) is unnecessarily complex and unwieldy, (b) has created problems with artificial distinctions between categories and artifactual comorbidity, and (c) at the same time obscures what may be more fundamental distinctions. A potentially useful and more parsimonious approach to capturing much of the heterogeneity of depressive disorders is to classify the depressive disorders along 2 dimensions, 1 reflecting severity and the other, chronicity. Considerations in the development of these dimensions are discussed, and a set of examples is presented. Although further research and discussion are needed to determine the optimal form of these dimensions, the next edition of the DSM should consider replacing many of the existing categories and specifiers for depressive disorders with the simpler approach of classifying depressive disorders using the 2 dimensions of severity and chronicity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The laryngeal mask airway: a new standard for airway evaluation in thoracic surgery

BACKGROUND: Thoracic surgeons typically perform fiberoptic bronchoscopy (FOB) before thoracotomy, usually on the day of the operation after intubation with a single-lumen endotracheal tube (ETT) and before insertion of a double-lumen ETT. This routine requires two laryngoscopies and two intubations. The laryngeal mask airway (LMA) is an airway device developed in England and approved by the Food and Drug Administration in 1991 for clinical use in the United States. It requires neither mask ventilation nor laryngoscopy and allows FOB visualization of the epiglottis, larynx, and entire trachea. We assessed the LMA as an alternative to a single-lumen ETT for FOB before thoracotomy. METHODS: Through prospective assessment, 50 patients underwent FOB after insertion of an LMA before thoracotomy. Pulse rate, blood pressure, ease of insertion of the LMA, quality of FOB, and complications of LMA insertion were assessed. RESULTS: During LMA insertion, blood pressure and pulse rate increased less than 5% from baseline in all patients. The LMA was inserted successfully in all patients within 10 seconds. No complications occurred as a result of LMA insertion. CONCLUSIONS: Insertion of the LMA causes minimal hemodynamic response. From the time of induction of general anesthesia, insertion of the LMA is quick, simple, and safe and eliminates the need for endotracheal intubation with a single-lumen ETT before double-lumen tube insertion. The LMA, in contrast to the ETT, allows a complete survey of the larynx and trachea. The LMA is autoclavable, reusable, and cost effective. Therefore, in patients who require FOB immediately before thoracotomy, LMA use should be the standard for airway evaluation.     

Elective surgery for colorectal cancer in the aged: a clinical-economical evaluation

Quality of life was measured by means of the sickness impact profile (SIP) questionnaire in a prospectively collected, consecutive series of 25 patients with perimesencephalic haemorrhage. A mean of two years and four months (range six months to six years) after the perimesencephalic haemorrhage, quality of life scores of the (former) patients were comparable with those of a random sample from the Dutch population. For physical aspects the patients showed even less dysfunction than controls. It is concluded that a perimesencephalic haemorrhage does not reduce quality of life or capacity to work.     

The evaluation of the postoperative response in surgery on the lower third molar

BACKGROUND: The impacted third molar is often excised in the absence of clear signs of disease. On this basis and taking also into account the usual surgical hazard, an analysis of the post-surgical behavior of 100 patients that had undergone excision of the impacted third molar, is made. METHODS: All patients were observed and treated by the same surgeon and were divided into two distinct groups based on the position and depth of the tooth in the bone as observed by orthopantomography. In the first group of patients, bone fenestration was carried out by the use of mallet and gouge and the tooth was excised without odontotomy. In contrast, in patients of the second group, odontotomy always preceded tooth excision. Patients of both groups were analyzed for several different parameters including age, sex, the reason for surgery, tooth position according to Pell and Gregory, the length of excision and, finally, swelling and the reduced mouth opening that occur after surgery. RESULTS AND CONCLUSIONS: Data reported indicate non-proportional results between the two groups; there is no apparent relation between post-surgical swelling and mouth opening, the latter being always present and very pronounced.     

The evaluation of a color-naming test for color blindness.

A simple color-naming test for color blindness was developed using the Eastman Color Temperature Meter, and compared with three other color-vision tests: the Farnsworth-Munsell 100-Hue Test, AO Pseudo-Isochromatic Plates, and Freeman Illuminant-Stable Color Vision Test on a sample of 100 Ss. "The data indicated that there was fairly high agreement among the American Optical, Eastman and Freeman tests… . The correlations of the Farnsworth with the other three tests were somewhat lower, indicating that the Farnsworth is apparently measuring factors not measured by the other tests… . It is significant that high correlations were obtained between naming and color competence." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Proposal of a concise index for the evaluation of the exposure to repetitive movements of the upper extremity (OCRA index)

In the light of data and speculation contained in the literature, and based on procedures illustrated in a previous research project in which the authors describe and evaluate occupational risk factors associated with work-related musculoskeletal disorders of the upper limbs (WMSDs), this article proposes a method for calculating a concise index of exposure to repetitive movements of the upper limbs. The proposal, which still has to be substantiated and validated by further studies and applications, is conceptually based on the procedure recommended by the NIOSH for calculating the Lifting Index in manual load handling activities. The concise exposure index (OCRA index) in this case is based on the relationship between the daily number of actions actually performed by the upper limbs in repetitive tasks, and the corresponding number of recommended actions. The latter are calculated on the basis of a constant (30 actions per minute) which represents the action frequency factor, and is valid-hypothetically-under so-called optimal conditions; the constant is diminished case by case (using appropriate factors) as a function of the presence and characteristics of the other risk factors (force, posture, complementary elements, recovery periods). Although still experimental, the exposure index can be used to obtain an integrated and concise assessment of the various risk factors analysed, and to classify occupational scenarios featuring significant and diversified exposure to such risk factors.     

A four-factor structure for parametric tests on independent groups.

A prior article by P. A. Games (1978) presented numerous statistical hypothesis-testing procedures for independent groups. These resulted from crossing 3 factors: technique used, method of control of Type 1 errors, and parameter used. Tests on means, correlations, proportions, and variances are represented by using θ for the parameter, and θ? for the statistic. The prior article was limited to cases in which the variance of the statistic V k(θ) was a constant and hence was limited to equal ns. The present article contains the extention to unequal V k(θ?) cases and hence permits unequal ns. More general large-sample forms of the t and F statistics, namely, the t′ and the df uF′ statistics, are recommended for the unequal V k(θ?) cases. The B. L. Welch solution for general contrasts on means is presented as a minor adaptation of t′. The Welch solution for an omnibus test on means is a minor adaptation of df uF′. Examples are given that illustrate the application of t′ and df uF′. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ethical issues in psychological evaluation of patients for organ transplant surgery.

Psychological assessment of patients seeking organ transplant surgery presents the potential for ethical conflict. Here confidentiality, informed consent, multiple loyalties, dual relationships, social justice, collaboration with families, responsibilities to donors, honesty, and avoidance of imposition of irrelevant moral values are discussed as they relate to the psychologist's relationship to the patient and to the enterprise of organ transplantation. The case examples of a 33-yr-old man with autoimmune hepatitis and a 55-yr-old woman with alcoholic cirrhosis highlight these issues. Relevant standards from the Ethical Principles of Psychologists and the Code of Conduct of the American Psychological Association are applied, as are principles of biomedical ethics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some experimental evidence for and against a parametric conception of movement programming.

In Experiment 1, subjects were supplied with prior information about 1, 2 or all dimensions (the active hand, direction, and extent) of a pointing movement. RTs showed that dimensional effects were found in highly compatible stimulus-response conditions, dimensions specification times were underadditive, and the difference in RT between dimension values when that dimension remained to be specified, disappeared when the dimension was precued. In Experiment 2, subjects were required to name target color after a set of colored targets was presented as a precue, and dimensional effects disappeared. In Experiment 3, a target was presented as a prime, followed by presentation of either the same or a different target. As compared to Experiment 1, dimensional effects were amplified. In conclusion, when two or more movement dimensions have to be specified simultaneously, dimension values are independently selected, then integrated in a compound programming operation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)