Biomedical subjects

Gail Barker

Publications and source records attributed to Gail Barker.

8 recordsLinked to original sources

PubMed2006

Dexamethasone dosing, mechanical ventilation and the risk of cerebral palsy.

OBJECTIVE: Risk factors for cerebral palsy (CP) in premature infants include duration of mechanical ventilation and exposure to postnatal dexamethasone (DEX). Since DEX can reduce the duration of mechanical ventilation, limited DEX exposure could be beneficial. METHODS: This was a retrospective, cohort study of infants of less than 1500 g birth weight surviving to discharge between 1 January 1996 and 30 June 2001 who received postnatal dexamethasone. DEX administration was based only on the need for O2 and/or mechanical ventilation. CP was diagnosed at over 10 months post-conceptional age. Univariate and multivariate analyses were used to determine significant risk factors and the relative contribution of these factors to overall risk of CP. RESULTS: Of 218 eligible infants 162 were followed-up (74%). The CP rate was 27.3%. Significant risk factors for CP included gestational age, ventilator duration, DEX dose, presence of periventricular leukomalacia (PVL), seizures, diagnosis of retinopathy of prematurity (ROP) and use of vasopressors. By multiple logistic regression, ventilator duration, PVL, grade III/IV intraventricular hemorrhage (IVH) and DEX dose were significantly related to CP. By stepwise multiple regression, grade III/IV IVH and ventilator duration were the strongest risk factors, but DEX dose continued to be a significant risk factor. CONCLUSIONS: The risk of CP was significantly related to the total cumulative dose of DEX. This could be due to a smaller exposure to DEX or to a reduced need for mechanical ventilation.

Adult↗

PubMed2004

An array microscope for ultrarapid virtual slide processing and telepathology. Design, fabrication, and validation study.

This paper describes the design and fabrication of a novel array microscope for the first ultrarapid virtual slide processor (DMetrix DX-40 digital slide scanner). The array microscope optics consists of a stack of three 80-element 10 x 8-lenslet arrays, constituting a "lenslet array ensemble." The lenslet array ensemble is positioned over a glass slide. Uniquely shaped lenses in each of the lenslet arrays, arranged perpendicular to the glass slide constitute a single "miniaturized microscope." A high-pixel-density image sensor is attached to the top of the lenslet array ensemble. In operation, the lenslet array ensemble is transported by a motorized mechanism relative to the long axis of a glass slide. Each of the 80 miniaturized microscopes has a lateral field of view of 250 microns. The microscopes of each row of the array are offset from the microscopes in other rows. Scanning a glass slide with the array microscope produces seamless two-dimensional image data of the entire slide, that is, a virtual slide. The optical system has a numerical aperture of N.A.= 0.65, scans slides at a rate of 3 mm per second, and accrues up to 3,000 images per second from each of the 80 miniaturized microscopes. In the ultrarapid virtual slide processing cycle, the time for image acquisition takes 58 seconds for a 2.25 cm2 tissue section. An automatic slide loader enables the scanner to process up to 40 slides per hour without operator intervention. Slide scanning and image processing are done concurrently so that post-scan processing is eliminated. A virtual slide can be viewed over the Internet immediately after the scanning is complete. A validation study compared the diagnostic accuracy of pathologist case readers using array microscopy (with images viewed as virtual slides) and conventional light microscopy. Four senior pathologists diagnosed 30 breast surgical pathology cases each using both imaging modes, but on separate occasions. Of 120 case reads by array microscopy, there were 3 incorrect diagnoses, all of which were made on difficult cases with equivocal diagnoses by light microscopy. There was a strong correlation between array microscopy vs. "truth" diagnoses based on surgical pathology reports. The kappa statistic for the array microscopy vs. truth was 0.96, which is highly significant (z=10.33, p <0.001). There was no statistically significant difference between rates of agreement with truth between array microscopy and light microscopy (z=0.134, p >0.05). Array microscopy and light microscopy did not differ significantly with respect to the number/percent of correct decisions rendered (t=0.552, p=0.6376) or equivocal decisions rendered (t=2.449, p=0.0917). Pathologists rated 95.8% of array microscopy virtual slide images as good or excellent. None were rated as poor. The mean viewing time for a DMetrix virtual slide was 1.16 minutes. The DMetrix virtual slide processor has been found to reduce the virtual slide processing cycle more than 10 fold, as compared with other virtual slide systems reported to date. The virtual slide images are of high quality and suitable for diagnostic pathology, second opinions, expert opinions, clinical trials, education, and research.

Equipment Design↗

PubMed2004

Clinical encounters costing for telemedicine services.

The Arizona Telemedicine Program (ATP) has developed a costing model that includes a number of factors contributing to the cost of providing services via telemedicine and generates a per-encounter cost. We first developed the model in 1999 and in this paper used it to analyze clinical services for the fiscal year 2000/2001. We evaluated the calculated weighted cost for providing those services via telemedicine as compared to the cost of providing those services "face-to-face." The cost of providing services via telemedicine was found to be lower when a patient had to travel 127.5 miles or more to receive clinical services. Our study provides analysis of the factors, their contribution to costs, as well as some factors, which are pertinent, but are more problematic to calculate. In this paper, we discuss the relevance of these results as they relate to telemedicine programs and a possible means to reduce costs even further.

Arizona↗

PubMed2004

Continuing education via telemedicine: analysis of reasons for attending or not attending.

This study analyzed factors that influence the decision to attend or not attend tele-education broadcasts via a telemedicine network for continuing education (CE) credits. A questionnaire was developed and sent to all participating sites on our telemedicine network that have attended CE broadcasts. The majority of respondents attend specific types of broadcasts, receiving less than 25% of their CE credits from the tele-education broadcasts. Factors most influencing the decision to attend a broadcast include interest in the topic and perceived utility of the information. The most common reason influencing the decision not to attend is an explicit preference for attending conferences. Tele-education broadcasts may supplement other CE activities but may not replace them. The attraction of attending conferences in person is very high and may be especially so for health-care professionals in rural environments.

Attitude of Health Personnel↗

PubMed2004

An analysis of unsuccessful teleconsultations.

Over six years, 4317 teleconsultations were scheduled in the Arizona Telemedicine Program. A total of 402 scheduled teleconsultations (9.3%) did not take place. A review showed that 254 were cancelled but eventually took place (5.9%), while 148 never took place (3.4%). The cost of a teleconsultation to the service provider was, at minimum, 228 US dollars. Telepsychiatry accounted for all the missed consultations that eventually took place, and 92% of these were from three of the six sites referring telepsychiatry patients. Pain management (23%) and psychiatry (21%) accounted for the largest proportions of teleconsultations that never took place. Telepsychiatry cases accounted for 71% of all unsuccessful consultations and accounted for only 34% of successful teleconsultations during the same period. Most missed teleconsultations had been scheduled as realtime sessions (84%). The most common reason for unsuccessful teleconsultations was that the patient did not attend (26%), followed by the patient having to be seen in person (17%). Although all referring sites had unsuccessful cases, certain sites accounted for more than others. These were sites that scheduled more telepsychiatry consultations than the others. The proportion of unsuccessful cases per site ranged from 4% to 17% of the total number of scheduled teleconsultations.

Adult↗

PubMed2004

The challenges of following patients and assessing outcomes in teledermatology.

We retrospectively reviewed the follow-up and outcomes of 50 store-and-forward teledermatology patients, and compared the findings with those from a control group of 50 patients who had been seen in person. Patient records were examined for a six-month period following the initial referral to a dermatologist. Variables examined included medical records from the referral, evidence of actions taken (e.g. biopsy), evidence of follow-up visits, and what (if any) clinical outcomes were noted. There were few differences between the teledermatology and in-person groups. The main difference was whether there was any report in the record that the referring clinician took some action based on the consultation with the specialist: there were more reports of action being taken in the teledermatology group than in the in-person group. Reports of outcomes were found in only 6% and 8% of the records of the teledermatology and in-person groups, respectively. The challenges of assessing outcomes in teledermatology for rural patients include patient loss to follow-up, lack of information in the patient records and low rates of patient return to the referring clinician for follow-up.

Dermatology↗

PubMed2003

Are there socio-economic inequalities in age of resection of colorectal cancer in people with HNPCC?

The relationship between socio-economic status and health has been consistently reported and is thought to be causal. Socio-economic inequalities are present in the incidence of and mortality from cancer in general, but not in the incidence of colorectal cancer in particular. However, there are socio-economic gradients in mortality from colorectal cancer. The socio-economic distribution of incidence of and mortality from colorectal cancer in individuals with hereditary non-polyposis colon cancer (Lynch syndrome) is not known. It is possible that increased awareness of and access to screening for colorectal cancer amongst this group of individuals reduces the socio-economic gradients seen in the population as a whole. We investigated the relationship between socio-economic status and age of resection of colorectal cancer in a cohort of individuals with hereditary non-polyposis colon cancer. More affluent individuals tended to undergo surgical resection for colorectal cancers earlier in their lives than less affluent individuals. This relationship was bordering on statistical significance. This trend probably represents socio-economic variations in access to treatment. In addition, age based diagnostic criteria for hereditary non-polyposis colon cancer may, inadvertently, accentuate socio-economic inequalities in outcome.

Adult↗

PubMed2002

Telemedicine versus in-person dermatology referrals: an analysis of case complexity.

The goal of this study was to determine whether teledermatology referrals differ significantly from in-person referrals with respect to case complexity and diagnosis of cases referred. Teledermatology cases were compared to in-person cases seen by the same university dermatologist who also reviews the teledermatology cases. These were also compared with in-person cases evaluated by a different dermatologist at local clinics using traditional referral patterns. Study parameters included Current Procedural Terminology (CPT) codes as a measure of case complexity, International Classification of Disease (ICD) codes as a measure of case types, and time from referral to actual consultation. The most common CPT codes used for teledermatology were 99241 and 99242 with no significant differences in the frequency of assigned CPT codes for teledermatology versus in-person consultation. An analysis of the diagnostic codes revealed no significant differences between the types of cases referred to telemedicine and those referred for in-person consultation. Time between referral and actual encounter with the dermatologist was significantly shorter via telemedicine than either local or university clinic in-person visits.

Chi-Square Distribution↗