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Biomedical subjects

J F Osborn

Publications and source records attributed to J F Osborn.

At least 19 recordsLinked to original sources
PubMed2005

A chart of failure risk for noninvasive ventilation in patients with COPD exacerbation.

Knowing the likelihood of failure of noninvasive positive pressure ventilation (NPPV) in patients with exacerbation of chronic obstructive pulmonary disease (COPD) could indicate the best choice between NPPV and endotracheal intubation instituted earlier. For this purpose, two risk charts were designed (at admission and after 2 h of NPPV) that included all relevant measurable clinical prognostic indicators derived from a population representing the patients seen routinely in clinical practice. Risk stratification of NPPV failure was assessed in 1,033 consecutive patients admitted to experienced hospital units, including two intensive care units, six respiratory intermediate care units, and five general wards. NPPV was successful in 797 patients. Patients with a Glasgow Coma Score <11, acute physiology and chronic health evaluation (APACHE) II > or =29, respiratory rate > or =30 breaths x min(-1) and pH at admission <7.25 have a predicted risk of failure >70%. A pH <7.25 after 2 h greatly increases the risk (>90%). The risk charts were validated on an independent group of 145 consecutive COPD patients treated with NPPV due to an acute ventilatory failure episode. To identify patients with a probability of failure >50%, the sensitivity and specificity were 33% and 96.7% on admission and 52.9% and 94.1% after 2 h of NPPV, respectively. The prediction chart, based on data from the current study, can function as a simple tool to predict the risk of failure of noninvasive positive pressure ventilation and thus improve clinical management of patients tailoring medical intervention.

APACHE↗
PubMed2004

A rapid immunochromatographic assay for Helicobacter pylori in stool before and after treatment.

BACKGROUND: Current guidelines recommend non-invasive testing and treatment of young dyspeptic patients without alarm symptoms. AIM: To evaluate the accuracy of a new rapid immunochromatographic stool test to diagnose Helicobacter pylori infection before and after treatment compared with a gold standard. METHODS: Prospective, single-blind study, performed in a tertiary care hospital. A total of 303 consecutive dyspeptic patients underwent endoscopy with multiple biopsies. Infected patients were offered a treatment and invited to come back 4-6 weeks after the end of therapy to repeat the endoscopy. Patients were also asked to provide a stool sample before and after therapy. RESULTS: About 149 patients were H. pylori infected. The sensitivity and specificity before treatment were 91.3 and 93.5%; after treatment 92 and 100%. The likelihood ratios were robust enough to produce significant changes from pretest to post-test probability both in pre-treatment (LR+ = 14, LR- = 0.093) and post-treatment (LR+ = 19.6, LR- = 0.095). CONCLUSIONS: The novel immunochromatographic stool test is fast, easy to perform and provides good differentiation between positive and negative results. It might become a rapid near patients test easily performed in the doctor office.

Antigens, Bacterial↗
PubMed2003

A rapid, low-dose, 13C-urea tablet for the detection of Helicobacter pylori infection before and after treatment.

BACKGROUND: A new urea breath test (UBT) has been described which uses a tablet formulation of 13C-urea with citric acid and allows breath sampling to be performed as early as 10 min after ingestion of the tablet. AIM: To assess the diagnostic accuracy of tablet-based 13C-UBTs (50 and 100 mg 13C-urea) before and after Helicobacter pylori eradication treatment, compared with an endoscopy gold standard and a conventional 13C-UBT (75 mg 13C-urea). METHODS: Two hundred dyspeptic patients underwent endoscopy, followed by tablet-based 13C-UBTs (50 and 100 mg 13C-urea) and a conventional 13C-UBT (75 mg 13C-urea). H. pylori-infected patients were prescribed treatment and asked to return 4-6 weeks after the end of therapy for repeat endoscopy and 13C-UBTs. RESULTS: One hundred and thirteen patients were infected with H. pylori. The sensitivity and specificity of the conventional 13C-UBT were both 100%; the sensitivity and specificity of the 100-mg tablet-based 13C-UBT were 100% and 98.85%, respectively. For the 50-mg tablet-based 13C-UBT, cut-off values of the difference over baseline of between 1.65 and 3.15 provided a sensitivity and specificity of 100%. At follow-up, the sensitivity and specificity of the conventional and 100-mg tablet-based 13C-UBTs were both 100%. For the 50-mg tablet-based 13C-UBT, cut-off values of the difference over baseline of between 1.49 and 1.56 gave a sensitivity and specificity of 100%. CONCLUSIONS: New 10-min 13C-UBTs using tablet formulations of 13C-urea with citric acid are reliable for the assessment of H. pylori status pre- and post-treatment.

Biopsy↗
PubMed2003

Further statistics in dentistry. Part 9: Bayesian statistics.

Statistics can be defined as the methods used to assimilate data, so that guidance can be given, and conclusions drawn, in situations which involve uncertainty. In particular, statistical inference is concerned with drawing conclusions about particular aspects of a population when that population cannot be studied in full. Uncertainty arises here because the totality of the information is not available. Instead, to make inferences about the population, it is necessary to rely on a sample of data which is selected from the population; this sample data may be augmented, in certain circumstances, by auxiliary information which is obtained independently of the sample data. Clearly, uncertainty lies at the heart of statistics and statistical inference. This uncertainty is measured by a probability which therefore forms the crux of statistics and must be properly understood in order to interpret a statistical analysis.

Algorithms↗
PubMed2003

Further statistics in dentistry Part 8: Systematic reviews and meta-analyses.

A systematic review of research evidence is an efficient approach to integrating existing information, invariably a multiplicity of published articles, with a view to establishing whether the scientific findings are consistent. If so, it may be possible to draw conclusions and make recommendations about treatment regimens or observed effects which have greater credence than those obtained from individual studies. The systematic review relies on a specified checklist which determines which articles should be included in the review, and how each should be critically appraised to provide relevant information relating to the focus of the review.

Algorithms↗
PubMed2003

Further statistics in dentistry. Part 7: repeated measures.

Consider the situation in which there is a single quantitative variable of interest that is measured on each individual on several different occasions. Typically, these occasions are defined time points (usually including pre-treatment as well as various post-treatment times), so that each individual contributes a series of readings. The main objective of the study may be to compare the responses on this variable when each individual has been assigned to one of two or more treatments groups.

Analysis of Variance↗
PubMed2002

Further statistics in dentistry, Part 5: Diagnostic tests for oral conditions.

A diagnostic test is a simple test, sometimes based on a clinical measurement, which is used when the gold-standard test providing a definitive diagnosis of a given condition is too expensive, invasive or time-consuming to perform. The diagnostic test can be used to diagnose a dental condition in an individual patient or as a screening device in a population of apparently healthy individuals.

Costs and Cost Analysis↗
PubMed2002

Further statistics in dentistry. Part 4: Clinical trials 2.

The principles which underlie a well-designed clinical trial were introduced in a previous paper. The trial should be controlled (to ensure that the appropriate comparisons are made), randomised (to avoid allocation bias) and, preferably, blinded (to obviate assessment bias). However, taken in isolation, these concepts will not necessarily ensure that meaningful conclusions can be drawn from the study. It is essential that the sample size is large enough to enable the effects of interest to be estimated precisely, and to detect any real treatment differences.

Clinical Trials as Topic↗
PubMed2002

Further statistics in dentistry. Part 2: Research designs 2.

To facilitate statistical discussion, it is essential to have an understanding of factors, effects, interactions, confounding, bias, estimation and hypothesis testing, to name but a few terms commonly used in statistical investigations in dentistry. These terms were explained in the previous paper in this series. This second paper is concerned with describing and differentiating between the various research designs that may be adopted.

Dental Research↗
PubMed2002

Further statistics in dentistry: Part 1: Research designs 1.

This new series of articles is designed to supplement, rather than replace, the material contained in the earlier series on statistics in dentistry published in the British Dental Journal and subsequently made available in book form.(1) With the increasing availability of calculators, personal computers and computer statistical software packages, the need for details of the 'nuts and bolts' of statistical theory has diminished, but the need for an understanding of how and when such theory should be applied, and how studies should be designed to make best use of it, has probably increased. It is with these thoughts in mind that this new series is being offered.

Dental Research↗
PubMed2001

Factors associated with HIV testing: results from an Italian General Population Survey.

BACKGROUND: HIV testing, with appropriate counseling, can help prevent the spread of HIV infection. This study is the first national survey in Italy that examines factors associated with serotesting among Italian heterosexuals and is part of a European Concerted Action. METHODS: In 1998, a cross-sectional telephone survey was conducted on a random sample (n = 2,603) of the Italian population ages 18-49 years. Associations between HIV testing and risky sexual behaviors (multiple sexual partners in the past 5 years, intercourse with prostitutes, not always using condoms with a new sexual partner) and sociodemographic variables are examined separately for men and women using multiple logistic regression. RESULTS: The prevalence of having ever been tested for HIV, whether voluntarily or not, among heterosexual men and women is 27.0 and 32.8%, respectively. Voluntary testing is reported by 8.4% of heterosexual men and 6.1% of heterosexual women. Multivariate analysis shows that having multiple sexual partners significantly increases the odds of testing (Men: OR = 2.10; 95% CI: 1.3-3.4. Women: OR = 3.03; 95% CI: 1.7-5.4). Multiple logistic regression, controlling for risky behavior, shows also that persons ages 30-39 years have significantly higher probability of being tested than younger subjects (Men: OR = 3.30; 95% CI: 1.4-7.9. Women: OR = 2.61; 95% CI:1.1-6.4). Better educated women tend to have a higher probability of testing, but this increase is not significant at the 5% level. CONCLUSIONS: The prevalence of voluntary serotesting in Italy is lower than in other countries. Risky sexual behavior is associated with higher odds of testing; however, a high proportion of at-risk heterosexuals never sought testing. Particular attention should be dedicated to younger persons and to less educated women.

AIDS Serodiagnosis↗
PubMed2001

Serial measurements of C-reactive protein and interleukin-6 in the immediate postnatal period: reference intervals and analysis of maternal and perinatal confounders.

BACKGROUND: There is a wide range of reported sensitivities and specificities for C-reactive protein (CRP) and interleukin-6 (IL-6) in the detection of early-onset neonatal infection. This prompted us to assess reference intervals for CRP and IL-6 during the 48-h period immediately after birth and to identify maternal and perinatal factors that may affect them. METHODS: CRP and IL-6 values were prospectively obtained for 148 healthy babies (113 term, 35 near-term) at birth and at 24 and 48 h of life, and from their mothers at delivery. RESULTS: Upper reference limits for CRP at each neonatal age were established. At birth, CRP was significantly lower than at 24 and 48 h of life. Rupture of membranes > or =18 h, perinatal distress, and gestational hypertension significantly affected the neonatal CRP dynamics, but at specific ages. There was no correlation between CRP concentrations in mothers and their offspring at birth. The IL-6 values observed in the delivering mothers and in their babies at all three neonatal ages were negatively associated with gestational age. In the immediate postnatal period, IL-6 dynamics for term babies were significantly different from those for near-term babies. Maternal IL-6 concentrations correlated with babies' IL-6 concentrations only for term deliveries. Apgar score had a significant effect on babies' IL-6 values at birth. CONCLUSIONS: The patterns of CRP and IL-6 responses in the healthy neonate should be taken into account to optimize their use in the diagnosis of early-onset neonatal sepsis.

Adult↗
PubMed2000

Risk of spontaneous abortion in Italy, 1978-1995, and the effect of maternal age, gravidity, marital status, and education.

This paper describes the trend in the risk of spontaneous abortion in Italy from 1974 to 1995. There was a dramatic decline in the risk after the law that legalized induced abortion was passed in 1978, which implies that probably many induced abortions performed before 1978 were registered as spontaneous abortions. Data for 1991 have been extracted from the Italian national registers of births and abortions and analyzed to investigate the effects of maternal age, gravidity, marital status, and education on the risk of spontaneous abortion. In comparison with women under age 20 years, the risk is found to be increased for women aged 35-39 (odds ratio = 1.45) and women over age 40 (odds ratio = 3.10). The odds ratio is almost 2 for women who have been pregnant two or more times previously. Unmarried women have an increased risk (odds ratio = 1.33), but no important effect of education was observed. There is an important interaction between maternal age and gravidity. The risk of spontaneous abortion is excessively high for young women with high gravidity. It is hypothesized that this could be due to the effect of short intervals between pregnancies.

Abortion, Spontaneous↗
PubMed2000

Serum procalcitonin concentrations in term delivering mothers and their healthy offspring: a longitudinal study.

BACKGROUND: The reported sensitivities and specificities of procalcitonin (PCT) concentrations for the diagnosis of neonatal infection vary widely. A postnatal increase of PCT has been observed in healthy term newborns with a peak at approximately 24 h of age, and many questions remain regarding maternal and perinatal factors that may influence the normal PCT kinetics during the immediate postnatal period. METHODS: We prospectively investigated the association between the serum PCT values obtained from 121 mothers at delivery and serum PCT in their healthy, term offspring at birth as well as at 24 and 48 h of age. We also analyzed whether obstetric and perinatal factors would alter maternal and neonatal PCT response. RESULTS: PCT concentrations in the babies at birth were significantly higher than in the mothers (P <0.0001), with even larger differences at 24 and 48 h of age. None of the variables identified from maternal and perinatal histories had a significant effect on maternal PCT response. In the healthy neonate, the variables that significantly affected the concentration of PCT at birth were the mothers' PCT (P <0.01), maternal group B streptococcus colonization (P <0.05), and rupture of membranes >/=18 h (P <0.01). The coefficient of linear correlation between the mother's PCT concentration and that of the baby at birth was 0. 32 (P <0.01). The only variable that significantly altered the PCT concentration at both 24 (P <0.01) and 48 (P <0.01) h of age was rupture of membranes >/=18 h. Nonetheless, the PCT response observed during the 48-h period after birth among healthy babies born to mothers with risk factors for infection was well below that reported previously among age-matched neonates with sepsis. CONCLUSIONS: The postnatal increase of PCT observed in the healthy neonate with peak values at 24 h of age most likely represents endogenous synthesis. In estimating the sensitivities and specificities of PCT for diagnosis of sepsis throughout the initial 48 h of life, it is important to consider the normal PCT kinetics and the pattern(s) of PCT response in the healthy neonate.

Adult↗
PubMed1998

Sunscreen use, wearing clothes, and number of nevi in 6- to 7-year-old European children. European Organization for Research and Treatment of Cancer Melanoma Cooperative Group.

BACKGROUND: Previous epidemiologic studies have suggested that sunscreen use is associated with an increased risk of melanoma skin cancer. Because high nevi (mole) count in adults is a strong predictor of melanoma, we conducted a study examining the number of nevi in 6- to 7-year-old European children, according to their sunscreen use. METHODS: Whole-body and site-specific counts of nevi 2 mm or larger were performed in 631 children in their first year of primary school in four European cities. Independently, parents were interviewed regarding sun exposure, sunscreen use, and physical sun protection of their child. RESULTS: After adjustment for sun exposure and host characteristics (e.g., skin phototype, eye color), the relative risk for high nevus count on the trunk was 1.68 (95% confidence interval [CI] = 1.09-2.59) for the highest level of sunscreen use and 0.59 (95% CI = 0.36-0.97) for the highest level of wearing of clothes while in the sun. The sun protection factor had no effect on nevus counts despite a high median value of 17.4. Sunburn number was not associated with nevus count. The highest risk associated with sunscreen use was found among children who had never experienced sunburn. CONCLUSIONS: In white, European children, sunscreen use appears to be associated with development of nevi, probably because it allows longer sun exposures. Wearing clothes may be an effective way to prevent proliferation of nevi. Since a high nevus count is a strong predictor of melanoma, sunscreen use may be involved in melanoma occurrence because it may encourage recreational sun exposure.

Child↗