Initial evaluation of a continuous speech recognition program for radiology

The aims of this work were to measure the accuracy of one continuous speech recognition product and dependence on the speaker's gender and status as a native or nonnative English speaker, and evaluate the product's potential for routine use in transcribing radiology reports. IBM MedSpeak/Radiology software, version 1.1 was evaluated by 6 speakers. Two were nonnative English speakers, and 3 were men. Each speaker dictated a set of 12 reports. The reports included neurologic and body imaging examinations performed with 6 different modalities. The dictated and original report texts were compared, and error rates for overall, significant, and subtle significant errors were computed. Error rate dependence on modality, native English speaker status, and gender were evaluated by performing ttests. The overall error rate was 10.3 +/- 3.3%. No difference in accuracy between men and women was found; however, significant differences were seen for overall and significant errors when comparing native and nonnative English speakers (P = .009 and P = .008, respectively). The speech recognition software is approximately 90% accurate, and while practical implementation issues (rather than accuracy) currently limit routine use of this product throughout a radiology practice, application in niche areas such as the emergency room currently is being pursued. This methodology provides a convenient way to compare the initial accuracy of different speech recognition products, and changes in accuracy over time, in a detailed and sensitive manner.     

The influence of technology assessments by advisory bodies on health policy and practice

Assessments of 45 health technologies undertaken by Australian advisory bodies are considered in terms of the effect they have had on health care policy. The conduct and impact of the assessments was influenced by selection of topics, timing, other inputs to policy formulation and changes to policy areas and assessment agencies. Seventeen of 26 detailed assessments appear to have influenced policy, with greatest impact occurring when the technology was being introduced and there was collection of local primary data. Continued requests for the assessment reports suggests a possible longer term educational effect. All nine appraisals of proposals for nationally funded centres were influential, but the influence of guidelines for superspecialty services is less clear. Factors decreasing the influence of assessments included limitations of available policy instruments, lack of consensus between governments and professional groups and pressure of more urgent matters on the policy process.     

The relative effectiveness of three reminder letters. On making and keeping mammogram appointments

One hundred fifty women who had previously had at least one mammogram were sent one of three prompt letters informing them that they were due for screening. The letters were either reassuring, anxiety provoking, or the standard hospital prompt. Based on a review of the literature, we hypothesized that the reassuring letter would be most effective in motivating women to schedule and keep appointments, the anxiety-provoking letter would produce an intermediate level fo compliance, and the standard hospital letter would be least effective. Our hypothesis was partially supported. Overall, 45% of the women in the study scheduled mammogram appointments. This included 54% of those who received the reassuring letter, 42% of those who received the anxiety provoking letter, and 38% of those who received the standard letter. Although the results were in the predicted direction, the results of a chi-square test indicated that differences among groups were not statistically significant. When the dependent measure was number of appointments kept, rather than scheduled, however, significantly more women who received the reassuring letter actually kept their appointments compared with those who received the standard hospital letter. Subsequent analyses suggested that having a family history of breast cancer, receiving a reassuring letter, and being older than 50 years were important factors in scheduling appointments.     

Objective Pulse-Synchronous "Essential" Tinnitus due to Narrowing of the Transverse Dural Venous Sinus

Subjective tinnitus is a common problem with many etiologies. Objective tinnitus, in which the sound is perceived by both the patient and the examiner, is less common. Objective tinnitus of the vascular type, in which a pulse synchronous bruit is heard by an independent observer, is frequently related to an underlying arterial or arteriovenous malformation, most commonly a dural arteriovenous fistula (DAVF) involving the transverse and sigmoid sinuses. The remaining cases are usually termed "essential" vascular tinnitus, and are presumed to have a venous etiology. In these cases, the audible noise is generally assumed to be produced within the sino-jugular connection, or within an enlarged jugular bulb. We present four documented cases of objective pulse synchronous tinnitus due to focal narrowing (acquired and developmental) of the mid-portion of the transverse dural sinus. In all cases, a bruit was audible directly over a focal constriction in the sinus, demonstrated by cerebral angiography or direct catheter venography. In one case, selective venography revealed a distensible sinus narrowing, associated with a jet of contrast marking fast flow within a developmental sinus segmentation. In another case, a loud pulse synchronous bruit was heard directly over a focal transverse sinus stenosis, which was detected by angiography at the site of a vascular surgical clip. In this case, magnetic resonance (MR) falsely predicted sinus occlusion. In two other cases, an audible bruit was also heard directly overlying a narrowed transverse sinus, seen in the venous phase of angiography. Transverse sinus stenosis is an unappreciated cause of objective pulsatile tinnitus, and we believe that this mechanism may underlie many cases of "essential" or venous etiology tinnitus not otherwise anatomically explained. Non-invasive testing, computed tomography (CT) and MR and non-directed angiography may overlook it. Conventional catheter arteriography or venography should be performed in such cases, with attention to the dural sinuses, if other tests fail to define the anatomic basis of the audible bruit.     

Economic evaluation of the cochlear implant

OBJECTIVE: To examine the economic efficiency of current cochlear implant technology under Australian conditions in profoundly deaf adults, partially deafened adults, and children. METHODS: Cost-utility study, with weights based on judgments from persons experienced with the technology, and cost data from Australian sources. RESULTS: Quality-of-life improvements due to functional consequences of hearing improvement were greater than those due to amelioration of hearing disability. Costs in Australian dollars per QALY (15-year assessment) ranged from $5,070-$11,100 for children, $11,790-$38,150 for profoundly deaf adults, and $14,410-$41,000 for partially deaf adults. CONCLUSIONS: Results suggest cochlear implantation is acceptable value for money when compared with other health programs to which resources are committed in Australia.     

Proceedings of the Symposium ‘Angiotensin AT1 Receptors: From Molecular Physiology to Therapeutics’: PHYSIOLOGICAL ACTIONS OF ANGIOTENSIN II MEDIATED BY AT1 AND AT2 RECEPTORS IN THE BRAIN

• 1 Autoradiographic binding studies have shown that the AT₁ receptor is the predominant angiotensin II (AngII) receptor subtype in the central nervous system (CNS). Major sites of AT₁ receptors are the lamina terminalis, hypothalamic paraventricular nucleus, the lateral parabrachial nucleus, rostral and caudal ventrolateral medulla, nucleus of the solitary tract and the intermediolateral cell column of the thoraco-lumbar spinal cord.
• 2 While there are differences between species, AT₂ receptors are found mainly in the cerebellum, inferior olive and locus coeruleus of the rat.
• 3 Circulating AngII acts on AT₁ receptors in the subfornical organ and organum vasculosum of the lamina terminalis (OVLT) to stimulate neurons that may have a role in initiating water drinking.
• 4 Centrally administered AngII may act on AT₁ receptors in the median preoptic nucleus and elsewhere to induce drinking, sodium appetite, a sympathetic vasoconstrictor response and vasopressin secretion.
• 5 Recent evidence shows that centrally administered AT₁ antagonists inhibit dipsogenic, natriuretic, pressor and vasopressin secretory responses to intracerebroventricular infusion of hypertonic saline. This suggests that an angiotensinergic neural pathway has a role in osmoregulatory responses.
• 6 Central angiotensinergic pathways which include neural inputs to the rostral ventrolateral medulla may use AT₁ receptors and play a role in the function of sympathetic pathways maintaining arterial pressure.

     

The assessment of diagnostic imaging technologies: a policy perspective

Diagnostic imaging technologies are essential in health care but have high costs and poorly defined benefits. Formulation and implementation of policy on their procurement and use is made difficult by the complexity of the diagnostic process, and the limitations of available data and assessment methodology. Informed policy decisions will need to be based on a synthesis of imperfect data from a variety of perspectives, and supplemented by effective dissemination and feedback of information. A list of attributes for consideration in the policy formulation process is presented.     

Actigraphically recorded motor activity and immobility across sleep cycles and stages in healthy male subjects

The aim of this study was to compare the extent to which activity and immobility measures are related to sleep stages and sleep cycles in order to improve the informative value of actigraphic assessment of sleep. We therefore performed simultaneous ambulatory polysomnography and wrist-activity monitoring (AM) in 14 healthy male subjects without sleep complaints. In this context, a simple method for transforming raw motor activity data into a time-series reflecting onset and duration of activity and immobility clusters is introduced. Our results demonstrate that nocturnal AM measures were significantly affected by sleep stage. Low activity levels and particularly prolonged episodes of uninterrupted immobility were associated with increasing sleep depth. On the other hand, high activity levels and prolonged episodes of activity were related to intermittent wakefulness during sleep. Our results suggest that measures reflecting the occurrence and duration of activity and immobility clusters provide a better approach in studying the relationship between activity/immobility and sleep stages. Except for the duration of uninterrupted immobility episodes, which showed a significant decrease in the fourth cycle, none of the AM measures showed a significant cycle-to-cycle variation. Consequently, mean nocturnal motor activity measures provide an accurate reflection of the total sleep period. However, none of the AM-derived measures seems useful in evaluating the cycle structure during sleep.