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Biomedical subjects

T Y Ching

Publications and source records attributed to T Y Ching.

At least 19 recordsLinked to original sources
PubMed2003

Effectiveness of precautions against droplets and contact in prevention of nosocomial transmission of severe acute respiratory syndrome (SARS).

We did a case-control study in five Hong Kong hospitals, with 241 non-infected and 13 infected staff with documented exposures to 11 index patients with severe acute respiratory syndrome (SARS) during patient care. All participants were surveyed about use of mask, gloves, gowns, and hand-washing, as recommended under droplets and contact precautions when caring for index patients with SARS. 69 staff who reported use of all four measures were not infected, whereas all infected staff had omitted at least one measure (p=0.0224). Fewer staff who wore masks (p=0.0001), gowns (p=0.006), and washed their hands (p=0.047) became infected compared with those who didn't, but stepwise logistic regression was significant only for masks (p=0.011). Practice of droplets precaution and contact precaution is adequate in significantly reducing the risk of infection after exposures to patients with SARS. The protective role of the mask suggests that in hospitals, infection is transmitted by droplets.

Case-Control Studies↗
PubMed2001

Curtailing unnecessary vancomycin usage in a hospital with high rates of methicillin resistant Staphylococcus aureus infections.

AIMS: To implement and monitor the effectiveness of a strategy to curb unnecessary use of vancomycin and teicoplanin for inpatients in a teaching hospital/tertiary referral centre where 33% of S. aureus isolates (72% from ICU patients) were methicillin resistant. METHODS: A sample of 182 vancomycin/teicoplanin inpatient prescriptions surveyed, revealed that only 31 (17%) conformed with Centre for Disease Control (CDC) guidelines. Following education (ward-rounds, bulletins) on appropriate CDC based guidelines for prescribing glycopeptides directed at relevant clinicians, 'Immediate Concurrent Feedback' (ICF) was gradually deployed throughout the hospital. This entailed review of respective inpatient records on the next working day. If the indication was deemed not to conform with our guidelines, the prescriber was issued a memo (copied to the supervising doctor). Each memo detailed the 'errant' incident, listed appropriate indications and explicitly advised desisting from such prescribing and suggested alternative therapy if necessary. Corresponding glycopeptide usage data for our hospital and others in Hong Kong were retrieved and analysed as were samples of records of our inpatients with staphylococcal septicaemia (pre and during ICF). RESULTS: Compared with baseline values, during 2 years of ICF, inpatient prescribing of vancomycin and teicoplanin deemed to conform increased to 71% (773/1086); difference 54% (P < 0.0001, 95% CIs 47-62%). Corresponding average monthly usage (DDDs/1000 admissions) decreased from 76 (pre-ICF) to 45; mean difference 31 (P < 0.0001, 95% CIs 24, 38). Mortality from staphylococcal bacteraemia remained unchanged. No comparable changes in glycopeptide usage ensued in comparator hospitals. CONCLUSIONS: ICF can be used safely to curb irrational overuse of vancomycin and teicoplanin in a hospital with high methicillin resistant S. aureus infection rates.

Anti-Bacterial Agents↗
PubMed2001

Children's amplification needs--same or different from adults?

Hearing aid fitting strategies for children have largely developed separately from those for adults. There has, however, been little consideration of whether children's amplification requirements are different, except for the physical effects of differences in ear canal size. This paper summarizes the fitting strategies for children, and examines whether children require more (or less) gain for high-, medium- or low-level sounds, or a different frequency response, compared with adults with similar hearing loss. Research relating to the above questions is reviewed. The gain that children require for high-level sounds is not different than for adults because loudness discomfort levels are similar. The gain children prefer for medium-level sounds is the same, or only slightly more, than is preferred by adults. Children may require greater gain for low-level sounds because they do require higher signal levels to achieve the same level of speech understanding as adults do. There are, however, arguments why more gain for low-level sounds may not be desirable. The frequency response children prefer is the same as that preferred by adults. New methods for evaluating individual fittings are briefly discussed.

Adolescent↗
PubMed2001

Maximizing effective audibility in hearing aid fitting.

OBJECTIVE: This paper examines why more audibility is not always better than less audibility if hearing-impaired people are to best understand speech. DESIGN: We used speech perception data from 14 normally hearing and 40 hearing-impaired people to quantify the contribution of audibility to speech intelligibility. The quantification revealed that the effectiveness of audibility decreased with hearing loss, and the decrement was greater at high frequencies than at lower frequencies. To apply the Speech Intelligibility Index (SII) model to predict speech intelligibility for hearing-impaired people, we modified the model to take account of effective audibility rather than physical audibility. RESULTS: The modified SII model provided an adequate description of speech performance of people with a wide range of hearing threshold levels. We applied the model to the evaluation of two prescriptions for a sloping audiogram at prescribed levels and at equated loudness levels to demonstrate the necessity of considering loudness and effective audibility in prescribing amplification. Effective audibility is defined as audibility corrected for the effects of level distortion and hearing loss desensitization, and this paper proposes a method of estimating effective audibility from hearing threshold level at different frequencies. CONCLUSIONS: The practical implication of considering effective audibility in prescribing hearing aids is that for a given listening level, less gain is provided at frequencies where the hearing is most impaired to allow more gain at frequencies where audibility is most useful. In developing the NAL-NL1 prescription for nonlinear hearing aids, we adopted the modified SII model together with a loudness model to derive optimal gain-frequency response characteristics that maximize predicted speech intelligibility for people with different degrees of hearing losses.

Audiometry, Speech↗
PubMed2001

Should children who use cochlear implants wear hearing aids in the opposite ear?

OBJECTIVE: The aim of this study was to investigate 1) whether a hearing aid needs to be adjusted differently depending on whether a child wears a cochlear implant or another hearing aid in the contralateral ear; 2) whether the use of a hearing aid and a cochlear implant in opposite ears leads to binaural interference; and 3) whether the use of a hearing aid and a cochlear implant in opposite ears leads to binaural benefits in speech perception, localization, and communicative functioning in real life. DESIGN: Sixteen children participated in this study. All children used a Nucleus 22 or Nucleus 24 cochlear implant system programmed with the SPEAK strategy in one ear. The hearing aid amplification requirements in the nonimplanted ear of these children were determined using two procedures. A paired comparison technique was used to identify the frequency response that was best for speech intelligibility in quiet, and a loudness balancing technique was used to match the loudness of speech in the ear with a hearing aid to that with a cochlear implant. Eleven of the 16 children participated in the investigation of binaural effects. Performance in speech perception, localization, and communicative functioning was assessed under four aided conditions: cochlear implant with hearing aid as worn, cochlear implant alone, hearing aid alone, and cochlear implant with hearing aid adjusted according to individual requirements. RESULTS: Fifteen of the 16 children whose amplification requirements were determined preferred a hearing aid frequency response that was within +/-6 dB/octave of the NAL-RP prescription. On average, the children required 6 dB more gain than prescribed to balance the loudness of the implanted ear for a speech signal presented at 65 dB SPL. For all 11 children whose performance was evaluated for investigating binaural effects, there was no indication of significantly poorer performance under bilaterally aided conditions compared with unilaterally aided conditions. On average, there were significant benefits in speech perception, localization, and aural/oral function when the children used cochlear implants with adjusted hearing aids than when they used cochlear implants alone. All individuals showed benefits in at least one of the measures. CONCLUSIONS: Hearing aids for children who also use cochlear implants can be selected using the NAL-RP prescription. Adjustment of hearing aid gain to match loudness in the implanted ear can facilitate integration of signals from both ears, leading to better speech perception. Given that there are binaural advantages from using cochlear implants with hearing aids in opposite ears, clinicians should advise parents and other professionals about these potential advantages, and facilitate bilateral amplification by adjusting hearing aids after stable cochlear implant MAPs are established.

Adolescent↗
PubMed1999

Improvements in speech perception with use of the AVR TranSonic frequency-transposing hearing aid.

Five adults with sensorineural hearing impairment participated in a trial comparing the performance of the AVR TranSonic frequency-transposing hearing aid with that of their own conventional aids. They used the TranSonic for approximately 12 weeks, during which time systematic changes were made to the transposition parameters. Speech perception was assessed with each setting of those parameters and with the participants' own hearing aids. Four participants obtained significantly higher scores with the TranSonic than with their own aids on at least one of the tests. However, analysis of the consonant confusions suggested that the improvement resulted mostly from the TranSonic's low-frequency electro-acoustic characteristics. There was only limited evidence for 2 of the participants that the frequency-lowering function was effective at improving speech perception.

Adult↗
PubMed1998

Antiulcer drug prescribing in hospital successfully influenced by "immediate concurrent feedback".

OBJECTIVE: To determine whether immediate concurrent feedback (ICF) focused on inpatient omeprazole prescribing achieved more rational and cost-effective antiulcer drug prescribing and usage. METHODS: In a 1400-bed teaching hospital, an audit (by specially trained personnel) was conducted to monitor inpatient prescribing of omeprazole (1) in preference to H2-antagonists and other drugs according to agreed criteria (Helicobacter pylori eradication, severe reflux esophagitis, rapid ulcer healing deemed urgent because of severe symptoms or complications, high-dose steroid therapy of > or =30 mg/day prednisolone) and (2) appropriateness of intravenous dosing (oral route not feasible or contraindicated). After baseline monitoring for 1 month, followed by relevant antiulcer drug therapy education, ICF was instituted for 1 year. This entailed explanatory memoranda requesting a change in prescribing issued to the respective medical teams of patients whose omeprazole prescription did not "conform." The main outcomes of the study were omeprazole prescription numbers per month and the proportion conforming, defined daily doses of antiulcer drugs used and corresponding expenditures, and pertinent antiulcer drug utilization data from 9 other local hospitals. RESULTS: Baseline omeprazole prescribing conformed in 32 of 173 (18%) of the patients compared with 451 of 546 (83%) during institution of ICF (P < 0001; chi2 test). Correspondingly, average overall omeprazole and ranitidine usage (inpatient and outpatient) and expenditure decreased (44% and 45%, respectively); collectively, use of less expensive alternatives increased about 61%. Estimated savings averaged about HK$150,000 ($20,000) per month. No comparable changes in usage were noted in 9 other local hospitals. CONCLUSION: Regarding hospital antiulcer drugs, this ICF strategy was associated with more rational prescribing and usage, and an important saving of resources.

Administration, Oral↗
PubMed1998

Speech recognition of hearing-impaired listeners: predictions from audibility and the limited role of high-frequency amplification.

Two experiments were conducted to examine the relationship between audibility and speech recognition for individuals with sensorineural hearing losses ranging from mild to profound degrees. Speech scores measured using filtered sentences were compared to predictions based on the Speech Intelligibility Index (SII). The SII greatly overpredicted performance at high sensation levels, and for many listeners, it underpredicted performance at low sensation levels. To improve predictive accuracy, the SII needed to be modified. Scaling the index by a multiplicative proficiency factor was found to be inappropriate, and alternative modifications were explored. The data were best fitted using a method that combined the standard level distortion factor (which accounted for decrease in speech intelligibility at high presentation levels based on measurements of normal-hearing people) with individual frequency-dependent proficiency. This method was evaluated using broadband sentences and nonsense syllables tests. Results indicate that audibility cannot adequately explain speech recognition of many hearing-impaired listeners. Considerable variations from audibility-based predictions remained, especially for people with severe losses listening at high sensation levels. The data suggest that, contrary to the basis of the SII, information contained in each frequency band is not strictly additive. The data also suggest that for people with severe or profound losses at the high frequencies, amplification should only achieve a low or zero sensation level at this region, contrary to the implications of the unmodified SII.

Adult↗
PubMed1997

Comparison of severely and profoundly hearing-impaired children's amplification preferences with the NAL-RP and the DSL 3.0 prescriptions.

Prompted by a recent paper in this journal (Snik et al., 1995), this communication compares the gain and frequency response preferred by a group of 21 severely and profoundly hearing-impaired children (37 test ears) to the NAL-RP and the DSL 3.0 hearing aid prescriptions. The results support the findings of Snik et al. (1995) that the NAL-RP procedure provides an adequate prescription of amplification on average. The individual discrepancies between prescribed and preferred characteristics imply that fine-tuning with an evaluation tool is necessary for some children. It is uncertain whether previous listening experience affects listeners' preferences, and it is suggested that further studies be carried out to address this issue.

Adolescent↗
PubMed1996

Hospital antibiotic prescribing successfully modified by 'immediate concurrent feedback'.

1. To determine the effectiveness of ongoing immediate concurrent feedback (ICF) in minimizing 'inappropriate' sultamicillin or co-amoxiclav prescribing via the parenteral route (i.e. when the oral route was accessible and not contraindicated), a prospective controlled audit was carried out on hospital inpatients over a 20 month period. 2. After an education programme to promote oral rather than unnecessary intravenous (i.v.) use of sultamicillin, co-amoxiclav and certain other drugs, an ongoing ICF strategy was instituted. 3. ICF entailed issue of memos on the following day to prescribers of i.v. sultamicillin or co-amoxiclav for inpatients in whom this route was deemed 'inappropriate', by a specially trained nurse using strict objective criteria. The memos recommended oral prescribing (particularly of co-amoxiclav, currently the less expensive alternative). 4. After starting ICF, there were consistent, clinically and statistically significant reductions in the monthly proportions of (i) admissions prescribed i.v. sultamicillin or co-amoxiclav (38% P < 0.001), (ii) those in whom the route was 'inappropriate' (75%, P < 0.001), and (iii) corresponding ratios of i.v./oral usage and expenditure, oral sultamicillin/co-amoxiclav usage and expenditure, as well as total and per admission expenditure on i.v. forms (> or = 43%, P < 0.01). 5. For i.v. cefuroxime (for which there was no ICF) and its oral counterpart cefuroxime-axetil, there were no comparable changes in usage or expenditure. 6. This simple, ongoing ICF strategy was effective and well accepted; estimated net monthly savings being HK$26-30,000.

Anti-Bacterial Agents↗
PubMed1994

Communication of lexical tones in Cantonese alaryngeal speech.

Cantonese is a tone language with six lexical tones. Each word has a distinctive tone, signaled by fundamental frequency variations at the syllable level. We investigated the relative efficiency of alaryngeal Cantonese speakers in conveying tonal variations in words in citation form. Isolated tone tokens were produced by three esophageal speakers, two tracheoesophageal speakers, two pneumatic artificial laryngeal speakers, and two electrolaryngeal speakers for perceptual tests. The correct responses from 22 listeners were highest for the pneumatic artificial laryngeal speakers, and could be graded in order of proficiency as esophageal, tracheoesophageal, and electrolaryngeal speakers. These results provide a linguistic perspective for guiding voice rehabilitation and the choice of voice in alaryngeal patients who speak a tone language.

Aged↗
PubMed1992

An outbreak of Candida tropicalis peritonitis in patients on intermittent peritoneal dialysis.

An outbreak of Candida tropicalis peritonitis in intermittent peritoneal dialysis patients during a 6-week period is reported from a general hospital. Five patients were involved and there were three deaths. The strains recovered from affected patients were identical to those recovered from the water baths on the basis of biotyping, antimicrobial susceptibility pattern and chromosomal DNA fingerprints. No further cases were identified on subsequent surveillance after the prohibition of wet-warming of peritoneal dialysate in the hospital.

Candidiasis↗
PubMed1991

The enhancement of infection control in-service education by ward opinion leaders.

Opinion leaders are members within a social group with significant social influence over others. A guideline on urinary catheter care was introduced in three groups (A, B, and C) of two randomly allocated wards. Two opinion leaders per ward were identified by nurses in groups A and B with the use of a sociometric method. For education, in-service lectures for 30% of nurses and opinion leaders' tutorials for all nurses were used in group A; opinion leaders' tutorials alone in B, and lectures alone in C. Before and after the education program, the guideline's frequency of practice was assessed by surveying 30% of randomly selected nurses and by direct observation. Results of the survey were comparable for groups A and B and both groups were significantly higher (p less than 0.05) than C, suggesting that informational transmission by opinion leaders was superior to that by the lecture. However, practices by direct observation in group A were significantly better (p less than 0.05) than those in B, indicating that staff compliance is best achieved by using both opinion leaders and lectures. The lecture probably endorsed the opinion leaders' leadership, enhancing their ability to influence the staff.

Communication↗
PubMed1990

Evaluation of staff compliance with 'influencing' tactics in relation to infection control policy implementation.

The efficacy of 'influencing' tactics for inducing compliance to infection control policies was assessed in 20 Hong Kong hospitals. In phase 1, 45 infection control nurses (ICNs) were surveyed on the frequency of use of possible tactics. Twenty-three of the more frequently used tactics were selected for phase 2 in which a random sample of 881 nurses were questioned on whether they would willingly, reluctantly or not comply with these tactics. Based on factor analysis of the responses in phase 2, six dimensions of compliance were identified. These were, in their order of effectiveness in achieving compliance: professional-resources (providing specialized or expert help); professional-respect (esteeming others as fellow professionals); coalition (obtaining staff support), ingratiation (cultivating goodwill), hierarchical (exerting pressure derived from rank) and non-communicative (ignoring or disregarding other's point of view).

Attitude of Health Personnel↗