Measurement errors in epidemiological studies of human papillomavirus and cervical cancer.

Measurement errors have been an important concern in studies of human papillomavirus (HPV) and anogenital cancers. Misclassification of HPV infection status is a possible explanation for incoherent findings in previous epidemiological studies purporting to show an etiological role for HPV in cervical cancer. Even low levels of misclassification of HPV infection can cause severe underestimation of HPV prevalence in field surveys, bias the association between HPV and sexual activity, and impair the ability to control statistically the relation between sexual activity and neoplasia by viral status. The present report focuses on aspects that have not been elaborated in two previous studies (Kaldor, 1989; Franco, 1991). Emphasis is given to effects of measurement errors of HPV infection status in biasing the association with cervical neoplasia under more complex scenarios, e.g., differential misclassification between cases and controls in a case-control study, and non-differential misclassification of both viral infection and cervical neoplasia in cross-sectional cytology surveys and cohort studies. Some simple numeric formulae are given that allow the correction of prevalence rates and epidemiological measures of effect, such as the odds ratio and the relative risk, under the latter conditions of misclassification constraint. These formulae have been used to correct estimates from recent epidemiological studies using hypothetical misclassification scenarios in order to obtain clues on the magnitude of the underlying relationship between HPV and cervical cancer.     

Quality of case management of sexually transmitted diseases: comparison of the methods for assessing the performance of providers.

This article examines the reliability and validity of direct observation of patient-provider encounters, interviews with providers, and use of patients simulating sexually transmitted diseases (STD) as methods for assessing the quality of STD case management in developing countries. Data were collected during an STD health facility survey in Malawi; the performance of 49 providers was observed, and the providers were also interviewed; 20 of them were visited by a simulated patient complaining of urethral discharge. Agreement (based on the kappa statistic) was generally poor between direct observation and provider-interview data, and also between direct observation and simulated-patient data. In contrast, percentage agreements between direct observation and simulated-patient data were often high. Multiple observations on providers indicated that a provider''s behaviour is not consistent across several patients. Simulated-patient data are probably the best in reflecting normal performance, but their feasibility for routine quality assessment is limited because the provider''s behaviour is not consistent and would require multiple data points. Direct observation data are the best option for assessing quality if the results are assumed to reflect better than normal levels of quality of care. Data from interviews with providers should be viewed with caution, because they may reflect provider knowledge and not necessarily performance.     

Method of single-lung transplantation in the absence of a left atrial cuff.

A method used clinically for anastomosing the pulmonary veins to the left atrium, in the absence of a left atrial cuff, during single-lung transplantation by reconstructing the atrium with pericardium is described. Postoperative ventilation/perfusion scans show normal pulmonary blood flow.     

Intraocular penetration of fosfomycin in man and rabbits

The intraocular distribution of fosfomycin was studied in 32 patients undergoing cataract surgery and or vitrectomy and in 8 rabbits after experimental infection of one eye by Staphylococcus aureus. In subjects perfused with 4 g of fosfomycin, concentrations ranged from 14 to 18.8 mg/l in aqueous humour (AH) and from 8 to 12.5 mg/l in vitreous fluid (VF) between 1 and 6 hours after the end of the perfusion; these levels were higher than MICs for 80-90 per cent of bacteria found in endophthalmitis. In rabbits the concentration in infected eyes with respect to healthy eyes was found to be from 2.5 to 5 times in AH and from 4.9 to 19.2 times higher in VF. Therefore fosfomycin in association with third generation cephalosporins (ceftriaxone) or with new quinolones can be recommended in the prevention and early treatment of endophthalmitis.     

Assessing postoperative discomfort after third molar surgery: a prospective study.

PURPOSE: The purpose of this study was to identify the risk factors for severe discomfort after mandibular third molar surgery and to assess the validity of the Postoperative Symptom Severity (PoSSe) scale. PATIENTS AND METHODS: In a 2-year prospective study, a total of 255 unilateral impacted mandibular third molar teeth were surgically removed under local anesthesia by 3 surgeons. Standardized surgical and analgesic protocols were followed. At the review appointment, 1 week after surgery, all patients returned a completed follow-up questionnaire (PoSSe scale) and were evaluated clinically for postoperative pain (number of painkillers taken) and trismus (differences in mouth opening). Sixteen predictive variables were evaluated using stepwise logistic regression analysis to identify the risk factors associated with severe discomfort. RESULTS: Severe postoperative discomfort was predicted by these independent variables: gender, tobacco use, ramus relationship/space available, and antibiotic prophylaxis. Oral contraceptive use and operation time were not identified as risk factors. The patients' perceptions of the severity of symptoms (PoSSe scale score) was strongly correlated with clinical assessment of trismus (r = 0.54) and pain (r = 0.42). CONCLUSION: The PoSSe scale resulted in a valid and responsive measure of the severity of symptoms after surgical extraction of lower third molars and reflected the clinical severity of the postoperative discomfort. From a patient's perspective, operative factors had little bearing on the quality of life after removal of mandibular third molars.     

Gender, suicidality and bipolar mixed states in adolescents

BACKGROUND: The purpose of this study was to determine the relationship between mixed states and suicidality among adolescent outpatients presenting with a DSM-IV defined major depressive episode (MDE). METHODS: Two-hundred and forty-seven adolescents meeting the criteria for MDE were screened for the presence of concurrent, intra-MDE hypomania/mania (i.e., mixed states). All patients were asked whether they had current suicidal ideation or had recently attempted any self-destructive physical act associated with the thought of dying (i.e., a suicide attempt). The data were subjected to analysis using univariate logistic regression. RESULTS: One hundred of the 247 (40.5%) adolescents were bipolar type I or type II. Of these, 82% were in mixed states. Of the patients with suicidal ideation, 62.8% were girls, and of those with histories of a suicide attempt, 69.4% were girls. Girls had more than twice the risk of having suicidal ideation (OR=2.2, p=0.004) and nearly 3 times the risk of having histories of a suicide attempt than boys (OR=2.87, p<0.0001). Being in a mixed state per se did not predict either suicidal ideation or a suicide attempt among all of the 247 patients. However, mixed states apparently independently contributed to the risk of (non-fatal) suicidal behavior among girls only. Of the mixed states, girls had nearly 4 times the risk of having made a suicide attempt compared with those without mixed states (OR=3.9, p=0.003). Age, presence of psychotic features and family history of mood disorder had little or no bearing on suicidality. LIMITATIONS: Correlational chart review study, no data collection on Axis I and Axis II comorbidity and adverse life-events. CONCLUSIONS: This report of greater suicidality in adolescent girls in a mixed state parallels the well-known adult literature of high frequency of mixed states in women. The findings are of relevance to the controversy of antidepressants and suicidality in juvenile depressives in that they identify a vulnerable group. In line with earlier suggestions by the senior author [Akiskal, H.S., 1995. Developmental pathways to bipolarity: are juvenile-onset depressions pre-bipolar? J. Am. Acad. Child Adolesc. Psych. 34, 754-763], our data highlight the public health importance of the wider recognition of bipolar mixed states in juvenile patients masquerading as unipolar depression. Finally, it appears to us that it is the failure of our formal nosology on mixed states--rather than the antidepressants per se--which is the root problem in this controversy.