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Biomedical subjects

K O'Brien

Publications and source records attributed to K O'Brien.

At least 55 records · Page 3Linked to original sources
PubMed1997

Measuring beliefs about orthodontic treatment: a questionnaire approach.

OBJECTIVES: Few studies have examined what parents and orthodontists expect from and value about orthodontic treatment. In this study, we designed and tested a questionnaire to outline what drives consumer demand for children's orthodontic care. Further, we present data from the questionnaire to illustrate how expectations and values pertaining to orthodontic treatment relate to sociodemographic variables. METHODS: Subjects were 220 Pennsylvania orthodontists and 220 parents at a university orthodontic clinic who were administered a questionnaire designed to assess what parents and orthodontists value about and expect from orthodontic treatment. Items for the questionnaire were developed via a qualitative, telephone interview process. Data were analyzed using factor analysis and reliability analysis for scale development, and analysis of variance for preliminary validity assessment. RESULTS: Through factor analysis, the questionnaire was reduced from 84 to 52 items, and eight scales were examined: expected treatment benefits, expected treatment risks (short- and long-term), expected treatment inconveniences, value of treatment benefits, value of risks (short- and long-term), and value of treatment inconveniences. For parents, the reliability for all scales was in the acceptable range. For orthodontists, only the "short-term risks" scale failed to attain an acceptable reliability. Preliminary validity was assessed through examining relationships between demographic variables and subscale scores. For parents, income, father's education level, and sex of respondent were related to treatment expectations and values. For orthodontists, age, sex, and patient volume were related to treatment values. CONCLUSIONS: The questionnaire developed in the present study was found to be practical and reliable for use with providers and consumers of orthodontic care and can be used to explore factors affecting the demand for orthodontic care. Implications of possible unrealistic treatment expectations on the part of orthodontists and parents also are discussed.

Adolescent↗
PubMed1997

High bone mass as a marker for breast cancer risk.

Postmenopausal women in the highest quartile for metacarpal bone mass were found to have an increased risk of developing breast cancer, after adjusting for age and other variables known to influence breast cancer risk. Although the mechanisms responsible for this relationship have not been identified, postmenopausal bone mass may serve as an indicator of cumulative estrogen exposure.

Bone Density↗
PubMed1996

Do dentists refer orthodontic patients inappropriately?

One concern to both providers and consumers of orthodontic treatment is the length of new patient consultation waiting lists. A possible reason for the excessive length of these lists could be unnecessary referral of patients. This research project aimed to identify whether inappropriate referrals for new patient orthodontic consultations were a significant problem. The study was carried out in two FHSA areas in the north of England in two stages. The first part of the study involved an evaluation of GDP referral patterns to orthodontic secondary care providers. In the second part, information on the patients referred by the dentists was collected. We concluded that there was a marked variation in referral rates between the dentists and many patients were referred unnecessarily. Importantly, there was no association between dentists' referral rate and the number of inappropriate referrals made. It appears that referral guidelines for orthodontic treatment are necessary and they should be directed at all general dental practitioners.

Adolescent↗
PubMed1996

Measurement of hydroxyl radicals catalyzed in the immediate vicinity of DNA by metal-bleomycin complexes.

A recently developed sensitive fluorimetric assay has been used to examine whether free hydroxyl radicals (HO.) are generated in the immediate vicinity of DNA by Fe(II)-bleomycin. When aqueous solutions of SECCA (the succinimidyl ester of coumarin-3-carboxylic acid) are irradiated with gamma rays or incubated with Fe(II)-bleomycin or Fe (II)-EDTA in the presence of ascorbate and H2O2, 7-hydroxy-SECCA, a fluorescent product of the interaction of HO. with SECCA, is generated. Studies with catalase and several HO. scavengers indicate that the fluorescence induction is mediated by HO. On the contrary, Cu(II)-bleomycin complexes under similar conditions fail to induce 7-hydroxy-SECCA fluorescence. When SECCA is conjugated to DNA via SECCA-polylysine-DNA complexes and incubated in the same iron-containing systems, the relative ability of the scavengers to reduce the fluorescence again demonstrates the generation of 7-hydroxy-SECCA by HO. However, while the fluorescence is practically eliminated by high concentrations of DMSO (100 mumols dm-3) in the systems with Fe(II) or Fe(II)-EDTA, it is not possible to reduce it similarly in the case of Fe(II)- bleomycin. These data demonstrate the generation of HO. by Fe(II)-bleomycin in the immediate vicinity of DNA. Because the experiments simulate the lifetime of HO. expected in cells, these data suggest that, if such DNA-associated HO. radicals are also produced in vivo by bleomycin, these would not be scavengable by intracellular scavengers and they could interact with chromatin.

Antibiotics, Antineoplastic↗
PubMed1996

Consistency of orthodontic extraction decisions.

Ten orthodontists having completed specialist training, examined on two occasions 1 month apart, the complete pre-treatment records of 60 Class II division 1 patients representing the full range of dental malocclusion severity. At each session the orthodontist recorded whether their proposed treatment involved extractions. The level of agreement both between and within the orthodontists was evaluated with the Kappa statistic. Data analysis revealed that the level of agreement within the examiners was good, however the between examiner agreement was poor. It appeared that the orthodontists were applying different criteria in terms of the extraction decision and this has implications for orthodontic patients.

Adolescent↗
PubMed1996

Perceptions of orthodontic treatment need: Receiver Operating Characteristic analysis.

This study aimed to investigate the variations in dentists' perception of need for orthodontic treatment. Sixteen dentists viewed forty clinical vignettes and recorded their decisions according to the certainty with which they would offer treatment for each case. Receiver Operating Characteristic (ROC) analysis was performed on this data, using the Index of Orthodontic Treatment Need (IOTN) as the "gold standard'. The data suggest that dentists treatment decisions do not concur with current guidelines in use in the UK.

Attitude of Health Personnel↗
PubMed1996

Factors influencing the uptake of orthodontic treatment.

The aim of this investigation was to evaluate the factors that influenced the uptake of orthodontic treatment for patients who were referred for orthodontic treatment to two types of orthodontic treatment provider; a fee per item and hospital service. The following data were collected: (i) basic demographic data; (ii) the need for orthodontic treatment as measured by IOTN; and (iii) the outcome of the consultation. The data analysis with logistic regression revealed that the following variables had a predictive effect on the uptake of treatment: (i) the need for orthodontic treatment; and (ii) the patient's gender. Most of the patients that were referred and accepted for treatment had a definite need for orthodontic treatment.

Adolescent↗
PubMed1996

Responders to antidepressant drug treatment: a study comparing nefazodone, imipramine, and placebo in patients with major depression.

BACKGROUND: Nefazodone hydrochloride, an antidepressant that acts as a 5-HT2 antagonist and serotonin (5-HT) and norepinephrine uptake inhibitor, was evaluated in a double-blind, imipramine- and placebo-controlled study involving 128 patients with major depression. METHOD: Eligible patients were randomly assigned to receive placebo (2 to 6 capsules/day), imipramine (100 to 300 mg/day), or nefazodone (200 to 600 mg/day) for 8 weeks. The principal efficacy outcome measure assessed was the number of patients who experienced an adequate response during treatment. RESULTS: Based on global improvement (Clinical Global Impressions-Improvement), 67% of nefazodone-treated patients (p < or = .01) and 63% of imipramine-treated patients (p < or = .05) responded during 8 weeks of treatment, compared with 36% of placebo controls. Sixty-two percent of nefazodone-treated, 53% of imipramine-treated, and 26% of placebo-treated patients had 17-item Hamilton Rating Scale for Depression (HAM-D-17) scores < or = 10 on completion of acute treatment. Nefazodone-treated patients had a lower incidence of premature treatment discontinuation and fewer dropouts for adverse events than the imipramine group. CONCLUSION: In a three arm comparison with imipramine and placebo, nefazodone had the greatest number of patients with major depression who responded to therapy. Nefazodone, a new antidepressant with novel pharmacology, is a well-tolerated, efficacious antidepressant.

Adult↗
PubMed1996

Health gain in orthodontics: a comparison of the general dental services and the hospital service in England and Wales.

The aim of this paper was to assess the health gain in orthodontics achieved by practitioners in the General Dental Service (GDS) and Hospital Dental Service (HDS) and the relative probabilities in achieving health gain in relation to the presenting occlusal trait. In a sample of 1225 patients in the GDS in England and Wales and 1365 cases in the HDS different levels of health gain were found. Occlusal traits are most likely to be treated more successfully in the HDS. Seven out of every ten patients in the HDS were likely to achieve health gain as opposed to four out of every ten patients in the GDS.

Dental Service, Hospital↗
PubMed1996

Index of Orthodontic Treatment Need, its use in a dental epidemiology survey calibration exercise.

The Index of Orthodontic Treatment Need (IOTN) was included in a pre-survey calibration exercise of 18 dental epidemiologists. Nine months later 16 of the epidemiologists were re-calibrated in the IOTN. The Index was readily accepted by the experienced dental epidemiological examiners and each examination was estimated to be extended by, on average, less than two minutes. The inter-examiner agreement of the dental health component using the weighted kappa statistic improved from a mean of 0.53 (moderate agreement) for the first calibration to 0.66 (good agreement) at the second calibration. The mean inter-examiner agreement on the aesthetic component using the weighted kappa statistic reduced from 0.52 for the first calibration to 0.49 at the second. Using sensitivity and specificity to measure agreement on the dichotomous decision of those defined as having a definite treatment need, mean sensitivity rose from 0.72 to 0.79 and specificity from 0.90 to 0.97. It is concluded that dental examiners for epidemiological surveys can be trained to use the IOTN by using a pre-calibration exercise and that agreement on the dental health component improves after the index has been used for some months.

Adolescent↗
PubMed1995

Dentists' perceptions of orthodontic services.

In this investigation the orthodontic referral patterns of the dentists working within two FHSA areas in the north of England were surveyed. A sub-sample of 149 of the dentists was selected and they were sent a postal questionnaire directed at their perceptions of the service provided and factors influencing their choice of orthodontist. One hundred and twenty one questionnaires (90%) were returned. It was found that 26.4 of the dentists did not refer an orthodontic patient and 51% referred to only one type of treatment provider. The most important factors governing their choice of orthodontic treatment provider were the length of treatment waiting list (62%) and the standard of treatment provided (66.9). In addition, the dentists' perceptions of the roles of the orthodontic services were not in concordance with those of the orthodontic treatment providers. They also expressed a degree of dissatistfaction with the orthodontic services.

Attitude of Health Personnel↗
PubMed1995

The validation of the Peer Assessment Rating index for malocclusion severity and treatment difficulty.

The Peer Assessment Rating (PAR) index is a British occlusal index that measures the severity of dental malocclusion and has been used in several investigations that have evaluated the effectiveness of orthodontic treatment provision in Europe. As part of its development, the PAR index was validated for malocclusion severity, by using the opinions of a panel of 74 dentists and orthodontists. The present investigation was carried out to validate the PAR index, by using the opinion of an American panel of orthodontists. Eleven orthodontists examined a sample of 200 sets of study casts and rated them for malocclusion severity and perceived treatment difficulty. Multiple regression techniques were used to evaluate the predictive power of the components of malocclusion on the panel's scores. Weightings were calculated from the partial regression coefficients and, when these weightings were applied to the PAR index, the association between the panel's opinion and the PAR index scores was increased.

Analysis of Variance↗