Validation of the Chinese version of the Pediatric Quality of Life Inventory (PedsQL) Cancer Module

OBJECTIVE

The psychometric properties of the Chinese version of the Pediatric Quality of Life Inventory (PedsQL) Cancer Module were investigated.

METHODS

This instrument and the Generic Core Scales were administered to 359 pediatric patients with cancer (5-18 years) and 413 parents of such patients (2-18 years old).

RESULTS

Seven and eight factors were, respectively, identified for the patient and parent versions. The Cronbach's alpha coefficients were respectively .89 and .92 for the total scale, and respectively .75-.90 and .76-.93 for the subscales of the patient and parent versions. Test-retest reliability coefficients exceeded .60 for most cases. The total/subscale scores of the Cancer Module significantly correlated with those of the Generic Core Scales. Some of the subscales could distinguish between on-treatment and off-treatment patients.

CONCLUSIONS

The psychometric properties of the patient and parent versions of the Chinese PedsQL Cancer Module were found acceptable.

Measuring the symptom experience of Chinese cancer patients: a validation of the Chinese version of the memorial symptom assessment scale

The purpose of this study was to translate the Memorial Symptom Assessment Scale (MSAS) into Chinese and evaluate the psychometric properties of this version. The original MSAS is a 32-item, patient-rated measure that was developed to assess common cancer-related physical and psychological symptoms with respect to frequency, intensity, and distress. In this study, a two-phase design was used. Phase I involved iterative forward-backward translation, testing of content validity (CVI) and a pretest. Phase II established the psychometric properties of the Chinese version MSAS (MSAS-Ch). Results showed that the MSAS-Ch achieved content relevancy CVI of 0.94 and semantic equivalence CVI of 0.94. Pretesting was performed in 10 cancer patients, and the results revealed adequate content coverage and comprehensibility of the MSAS-Ch. A convenience sample of 370 patients undergoing cancer therapy or at the early post-treatment stage was recruited for psychometric evaluation. Confirmatory factor analysis confirmed the construct validity of the MSAS-Ch, with a good fit between the factor structure of the original version and our present sample data (goodness-of-fit indices all above 0.95). The internal consistency reliability of subscales and total MSAS-Ch was moderately high, with Cronbach alpha coefficients ranging from 0.79 to 0.87. The test-retest intraclass correlation results for the subscale and total MSAS-Ch ranged from 0.68 to 0.79. The subscale scores of MSAS-Ch were moderately correlated with the scores on various validation measurements that assessed psychological distress, pain, and health-related quality of life (r = 0.46-0.65, P < 0.01), confirming that they were measurements of similar constructs. The validity of the construct validity was also supported by comparing the MSAS-Ch scores for subpopulations that varied clinically. Inpatients and patients with poorer performance status scored higher on the MSAS-Ch subscale and total scores than outpatients and patients with higher performance status (P < 0.05). Our study shows that the MSAS-Ch has adequate psychometric properties of validity and reliability, and can be used to assess symptoms during cancer therapy and at the early post-treatment stage in Chinese-speaking patients.

Longitudinal changes in the disability level of the elders with low back pain after auriculotherapy

OBJECTIVE

To evaluate the longitudinal changes in the disability level of elders with LBP after receiving auriculotherapy.

DESIGN

Randomized controlled trial.

SETTINGS

Sixty participants who were 60 years old or above and who were suffering from LBP were recruited from five hostels for the elders in Hong Kong.

INTERVENTIONS

The participants were randomly allocated to receive a 3-week session of auriculotherapy using either semen vaccariae (control group=30) or magnetic pellets (experimental group=30). Seven auricular acupoints that are expected to have an effect on LBP were selected.

MAIN OUTCOME MEASURES

Assessment data were collected at five points of time: (i) baseline, (ii) about 1.5 weeks of treatment, (iii) 3 weeks of treatment, (iv) 2 weeks post-treatment, and (v) 4 weeks post-treatment using the modified Aberdeen low back pain disability scale (Chinese).

RESULTS

When the rate of change was compared between the two groups at each point of time starting from the baseline, those in the experimental group demonstrated significant improvement in the overall disability level, pain/sensation, and physical and functional abilities at 1.5 weeks of treatment (p<0.001), 3 weeks of treatment (p<0.001), 2 weeks post-treatment (p<0.001), and 4 weeks post-treatment (p<0.001).

CONCLUSION

Longitudinal changes in the improvement of disability level were found among the elders with low back pain after receiving auriculotherapy using magnetic pellets.

Fetal methylmercury exposure as measured by cord blood mercury concentrations in a mother-infant cohort in Hong Kong

This study was designed to examine newborn infants in Hong Kong prenatally exposed to levels of methylmercury considered to increase risk of neurotoxic effects and to examine subject characteristics that modify the degree of prenatal mercury exposure. Mercury concentrations in 1057 sets of maternal and cord blood samples and 96 randomly selected maternal hair samples were measured. Subject characteristics were measured or collected by questionnaire. Of the 1057 cord blood samples collected only 21.6% had mercury concentrations less than 29 nmol/L (5.8 micro g/L). Median maternal hair mercury concentration was 1.7 ppm. The geometric mean cord to maternal blood mercury ratio was 1.79 to 1. Increasing maternal fish consumption and maternal age were found to be associated with increased cord blood mercury concentrations. Marine fish consumption increased cord blood mercury concentrations more than freshwater fish (5.09%/kg vs 2.86%/kg). Female babies, maternal alcohol consumption and increasing maternal height were associated with decreased cord blood mercury concentrations. Pregnant women in Hong Kong consume large amounts of fish and as a result, most of their offspring have been prenatally exposed to moderately high levels of mercury. In this population, pregnant women should choose freshwater over marine fish and limit fish consumption.

Parental suspicion of hearing loss in children with otitis media with effusion

OBJECTIVE

This study aimed to evaluate the parental suspicion of hearing loss in children with otitis media with effusion (OME). As part of a population-based survey in a screening programme among 6- to 7-year-old Chinese children in Hong Kong, OME cases and controls were studied for the value of parental observations in the prediction of OME and hearing test results.

SUBJECTS AND METHODS

Prior to the otoscopic and tympanometric examination of the children on school premises, a self-administered binary-choice question was sent to the parents asking whether there was any suspicion of hearing impairment. Positive screens and randomly selected negative screens were seen in a hospital clinic for the confirmation of case and control status 2 to 3 weeks after the school screening. Aural examination under microscopy, repeated tympanometry and stapedial reflex testing, and pure-tone audiometry (PTA) were conducted, and 117 cases and 159 controls were included in this study.

RESULTS

The average PTA conductive threshold levels in the individual children with OME ranged from 3.8 dB to 40.0 dB with a group mean of 17.0 dB in the better-hearing ears. Parental suspicion of hearing deficit was significantly associated with OME (p<0.001) but not PTA findings (p=0.686). The sensitivity of parent-suspected hearing impairment to detect OME however was very low (19.7%).

DISCUSSION

In other words, if we had relied on parental suspicion as the first screening, at least 80% of the OME cases would have been missed. We conclude that the parental suspicion of hearing loss is inadequate for the identification of mild hearing loss as caused by OME. Health education is recommended to improve parental awareness of the disease.

Validation of the Chinese version of the Satisfaction with the Nursing Home Instrument

AIM

To assess the psychometric properties of the Chinese version of the Satisfaction with the Nursing Home Instrument.

BACKGROUND

Resident's satisfaction has been regarded by the literature as a gold standard for quality of nursing home care. Accurate assessment of resident's satisfaction can provide valuable information for implementation of quality nursing home care. However, there is not a validated Chinese tool to serve the purpose.

DESIGN

A cross-sectional descriptive survey design.

METHODS

Content validity of the Chinese version of the Satisfaction with the Nursing Home Instrument was assessed by the use of expert panel. Construct validity of the Chinese version of the Satisfaction with the Nursing Home Instrument was determined by assessing the correlation between satisfaction with other theoretically related constructs. Internal consistency and stability of the Chinese version of the Satisfaction with the Nursing Home Instrument were determined by Cronbach's method and two-week test-retest reliability. The six-factor structure of the Chinese version of the Satisfaction with the Nursing Home Instrument was assessed by confirmatory factor analysis. Testing was performed on a cluster sample of 330 residents from 16 nursing homes in Hong Kong.

RESULTS

The Chinese version of the Satisfaction with the Nursing Home Instrument demonstrated good content validity by having content validity index of 0.93. High construct validity of the Chinese version of the Satisfaction with the Nursing Home Instrument was supported by its significant correlation with depression (r = -0.42, P = 0.000), health-related quality of life (physical component) (r = 0.16, P = 0.042), health-related quality of life (mental component) (r = 0.41, P = 0.000) and global quality of care (r = 0.49, P = 0.000). The Chinese version of the Satisfaction with the Nursing Home Instrument demonstrated satisfactory internal consistency and good stability by having Cronbach's alpha of 0.79 and intra-class correlation coefficient of 0.94, respectively. The six-factor structure of the Chinese version of the Satisfaction with the Nursing Home Instrument was not fully supported by confirmatory factor analysis.

CONCLUSIONS

The Chinese version of the Satisfaction with the Nursing Home Instrument is a useful instrument for assessing satisfaction of cognitively intact Chinese nursing home residents. Findings provided initial evidence on its validity and reliability. Further empirical testing is recommended to explore its factor structure.

RELEVANCE TO CLINICAL PRACTICE

The Chinese version of the Satisfaction with the Nursing Home Instrument can provide guidance to enhance delivery of high-quality nursing home care for the Chinese population.

Insulin and obstructive sleep apnea in obese Chinese children

OBJECTIVE

In adults, obstructive sleep apnea (OSA) is associated with insulin resistance and dyslipidemia. We aimed to establish correlation between OSA, serum lipid profile, and insulin levels in obese snoring children.

METHODS

Consecutive obese children with habitual snoring were recruited. They underwent physical examination, overnight polysomnography (PSG), and metabolic studies. OSA was diagnosed if apnea hypopnea index (AHI) > 1.0, and cases were considered to have moderate to severe OSA if AHI > 10.

RESULTS

Ninety-four obese subjects with habitual snoring were studied. Seventy-three subjects were male and the median age of the studied group was 12.0 years (IQR 9.7-13.9). None of the subjects had active cardiopulmonary disease, and the BMI values of our subjects were >95th percentile using local reference charts. Sixty subjects had OSA, 47 being mild, and 13 being moderate to severe OSA. Multiple logistic regression analysis revealed that saturation nadir and insulin levels were significantly associated with OSA.

CONCLUSION

OSA is prevalent among obese children with habitual snoring and insulin is independently associated with the condition. Its role in the cardiovascular complications of childhood sleep apnea is worthy of further exploration.

PinQ: a valid, reliable and reproducible quality-of-life measure in children with bladder dysfunction

OBJECTIVE

Recently, a cross-cultural continence-specific paediatric quality-of-life measurement tool (PinQ) has been developed and tested psychometrically. The aim of this study was to evaluate the test re-test reliability of this new tool in a cohort of children with bladder dysfunction in order to evaluate the reproducibility of scores. A secondary aim was to compare the parent-completed proxy version with child-reported scores.

METHODS

PinQ was translated and back-translated from English into Chinese and Dutch and scrutinized for cultural and linguistic appropriateness or ambiguity. Forty children aged 6-15 years from both countries were asked to self-complete the measure at first consultation and then again 14 days later. No new treatment was implemented between data collection points. On the initial visit, parents also completed a proxy version of PinQ. Intraclass correlations (one-way random effects model) were used to analyze the data.

RESULTS

The intraclass correlation coefficient (ICC) for comparison between items and factors showed little variability in scoring. One item was not reproducible and was removed from the tool. Overall proxy scores varied little from the child-reported scores. However, the impact on the child of his/her parent's concern about the bladder problem was poorly perceived (ICC=0.18) as was the impact on the child's sense of self-worth (0.17).

CONCLUSION

PinQ has been shown to be reliable under test re-test conditions when completed by children from the age of 6 years. Proxy PinQ suggests that parents accurately evaluate the effect of bladder dysfunction on wellbeing in their children. A 20-item measurement tool will now be introduced clinically and subjected to sensitivity testing for treatment outcome and diagnostic grouping.

Development of a validated quality of life tool specific to children with Bladder dysfunction

AIMS

To date there have not been any generic or continence-specific measurement tools that allow clinicians to investigate quality of life in children with bladder dysfunction. The aim of this research was to create a cross-cultural tool to assess and measure the wider psychosocial impact of current and new interventions for bladder dysfunction in children.

MATERIALS AND METHODS

The study was conducted in three parts: expert consultation with continence clinicians; design and administration of a child-completed international questionnaire; item analysis, validity and reliability testing, and design of a new tool.

RESULTS

The need for a pediatric incontinence QoL measure evaluation was strongly endorsed by clinicians. Data from 156 child-completed questionnaires collected in 10 countries was analyzed for item characteristics and found to be free of item correlation and ceiling and floor effects. Factor analysis revealed 2 factors, which were labeled intrinsic and extrinsic. Rasch analyses showed the internal validity of both subscales was reasonable good. Cronbach's alpha for each factor was 0.91 and 0.72. After analysis, items were selected for the new tool, PinQ, and evaluated for ambiguity, clarity, comprehension level required, choice of words and phrases, and age-appropriate concepts. Twenty-one items were finally selected and randomly positioned within the tool.

CONCLUSIONS

A cross-cultural tool that quantifies the holistic effect of bladder dysfunction in children has been designed and tested for validity.

Risk factors for otitis media with effusion in Chinese schoolchildren: a nested case-control study and review of the literature

OBJECTIVE

To identify the risk factors for otitis media with effusion (OME) in Chinese schoolchildren and analyse the results with reference to the review of the literature.

METHODS

The study subjects were 6-7-year-old children drawn from a school-screening program for OME in Hong Kong. Both positive and negative screens attended a hospital clinic for further assessment with repeated otoscopic examination and tympanometry as well as pure tone audiometry within 3 weeks after the initial school-screening. During the visit, parents were interviewed to provide information with regard to the children's birth history, neonatal history, socio-economic background, otological history, past health, and medical history. These data formed the basis in the estimation of potential risk factors for OME.

RESULTS

In the univariate analysis of 127 cases and 173 controls, significantly elevated odds ratios (OR) for OME were detected on the symptoms of atopy (OR = 2.21, p = 0.04), hearing loss (OR = 4.13, p = 0.001), nasal obstruction (OR = 1.94, p = 0.005), rhinorrhoea (OR = 1.61, p = 0.04), tonsillitis in the past 12 months (OR = 1.82, p = 0.02), and previous history of acute otitis media (OR = 6.89, p < 0.001). However, only three of them were found to be significant in the multivariate logistic regression model: nasal obstruction (OR = 1.67, 95% CI: 1.01-2.75); acute tonsillitis (OR = 1.68, 95% CI: 1.00-2.80), and previous acute otitis media episodes (OR = 5.75, 95% CI: 2.60-12.69).

CONCLUSIONS

Risk factors identified in the Chinese schoolchildren for OME were comparable with previous western reports. A previous attack of acute otitis media was a major determinant for middle ear effusion.

Longer term follow up of aerobic capacity in children affected by severe acute respiratory syndrome (SARS)

BACKGROUND

A study was undertaken to investigate the aerobic capacity and pulmonary function of children 6 and 15 months after the diagnosis of severe acute respiratory syndrome (SARS).

METHODS

Thirty four patients of mean age 14.7 years completed both pulmonary function and maximal aerobic capacity tests at 6 months. All had normal clinical examination and were asymptomatic. Their exercise responses were compared with a group of healthy controls. Complete data were collected on 27 of the original 34 cases at 15 months.

RESULTS

Compared with normal controls, the patient group had significantly lower absolute and mass related peak oxygen consumption (peak V o(2) (p<0.01)), higher ventilatory equivalent for oxygen (p<0.01), lower oxygen pulse (p<0.01), and a lower oxygen uptake efficiency slope (p<0.01) at 6 months. This impairment was unexpected and out of proportion with the degree of lung function abnormality. Residual high resolution computed tomography of thorax (HRCT) abnormalities were present in 14 patients. Those with abnormal HRCT findings had significantly lower mass related peak V o(2) than subjects with normal radiology (p<0.01). Absolute and mass related peak V o(2) in the patient group remained impaired at 15 months despite normalisation of lung function in all patients.

CONCLUSIONS

The mechanism for the reduced aerobic capacity in children following SARS is not fully understood, but it is probably a consequence of impaired perfusion to the lungs at peak exercise and deconditioning.

Depression is the predominant factor contributing to morale as measured by the Philadelphia Geriatric Morale Scale in elderly Chinese aged 70 years and over

OBJECTIVE

To examine factors contributing to the total Philadelphia Geriatric Morale Scale (PGMS) and its two subscales: reconciled ageing and unstrained affect.

METHOD

The PGMS was administered to 759 community-living subjects aged 70 years and over. Information regarding socioeconomic status, health conditions, sensory impairment, physical symptoms, social support, activities of daily living as measured by the Barthel Index, life satisfaction, and the Geriatric Depression Score, was collected. Associations between these factors and PGMS and its subscale were examined using univariate analysis (Mann-Whitney; Kruskal-Wallis tests), and multivariate analysis using the classification and regression tree (CART) method.

RESULTS

Gender, old age, physical, socioeconomic and social factors were significantly associated with PGMS. There was a strong correlation with GDS (r = 0.77, p < 0.001). In the CART analysis, for both subscales and the total score, GDS was the predominant factor contributing to the score. Other factors include self perception of health, enough expenses, overall satisfaction with life, gender, and constipation.

DISCUSSION

The PGMS and GDS are closely related. In addition to the GDS, health perception, life satisfaction, and adequate finance were factors contributing to quality of life in elderly Hong Kong Chinese.

Hepatic steatosis in obese Chinese children

OBJECTIVES

THE AIMS OF OUR STUDY WERE

(1) to determine the prevalence of asymptomatic hepatic steatosis and presumed nonalcoholic steatohepatitis, in our local population of obese Chinese children referred for medical assessment; and (2) to assess the correlation between severity of ultrasonographic hepatic steatosis and degree of obesity, insulin resistance and serum biochemical abnormalities.

DESIGN

Cross-sectional study.

METHODS

In total, 84 obese children, 25 girls and 59 boys with median age and body mass index (BMI) of 12.0 years (interquartile range (IR): 9.5-14.0) and 30.3 kg/m(2) (IR: 27.1-33.4), respectively, referred for medical assessment were studied. All subjects underwent physical examination, anthropometric and dual energy X-ray absorptiometry (DEXA) scan measurements and real-time ultrasonographic (US) examination of the liver. Fasting blood samples were collected for the measurement of liver function, hepatitis status, levels of serum glucose and insulin and lipid profile. Degree of fatty infiltration of the liver was graded according to ultrasonic appearance of liver echotexture, liver-diaphragm differentiation in echo amplitude, hepatic echo penetration and clarity of hepatic blood vessels.

RESULTS

All recruited subjects had no history of alcohol abuse and tests for Hepatitis B or C virus were negative. Thorough examination showed all of them to be in general good health without signs of chronic liver disease. Hepatic steatosis identified by defined ultrasonic appearances was diagnosed in 65 subjects (77%); 17 girls and 48 boys. The severity of fatty liver was positively related to anthropometric measurements including BMI, waist and hip circumference, subscapular skinfold thickness; insulin resistance markers [QUICKI and homeostasis model assessment (HOMA)], and hypertriglyceridaemia. Multvariate ordinal regression analysis showed that BMI and raised alanine aminotransferase (ALT) were positively associated with fatty liver. Combination of hepatic steatosis with raised ALT (presumptive NASH) was found in 19 subjects (24%). This group of patients had significantly higher waist hip ratio and conicity index compared to those with isolated hepatic steatosis. Boys with presumed NASH were also found to have significantly higher insulin resistance.

CONCLUSION

Nonalcoholic fatty liver disease (NAFLD) was common among our cohort of obese children referred for medical assessment. The prevalence of simple steatosis and presumed NASH was 77 and 24%, respectively. The severity of US steatosis was positively correlated with BMI, raised ALT, insulin resistance and hypertryglyceridaemia. Ultrasonography being noninvasive and readily available could be used for the monitoring of the progression of hepatic steatosis. Further longitudinal studies are required to determine the natural disease progression and the role of insulin resistance and other factors in the pathophysiology of NAFLD.

Beating heart revascularization with or without cardiopulmonary bypass: evaluation of inflammatory response in a prospective randomized study

OBJECTIVE

On-pump beating heart coronary artery surgery provides the opportunity to examine the isolated effect of cardiopulmonary bypass. This prospective randomized study compares the early clinical outcomes and inflammatory response of patients undergoing elective on-pump and off-pump beating heart coronary artery bypass grafting.

METHOD AND PATIENTS

Thirty-seven consecutive patients undergoing elective coronary artery bypass grafting were recruited from a pool of 73 patients, with 19 patients randomized to on-pump beating heart surgery and 18 patients to off-pump coronary bypass surgery. Intraoperative events and postoperative outcomes were recorded. Plasma levels of interleukin-6, interleukin-8, and interleukin-10, tumor necrosis factor-alpha, and vascular cell adhesion molecule-1 were measured before the operation, intraoperatively, after the operation, and 4, 24, and 48 hours thereafter.

RESULTS

There was no significant difference in clinical outcomes between the 2 groups. The operating time was longer and consumption of platelets was greater for the on-pump beating heart group. There was no postoperative mortality or major complication in either group. There was significant elevation in the levels of interleukin-6, interleukin-8, and interleukin-10 and tumor necrosis factor-alpha during and immediately after the operations in the on-pump beating heart group when compared with the off-pump group. Levels of interleukin-8 (P =.01) and tumor necrosis factor-alpha (P =.0004) remained significantly elevated 4 hours after the operation in the on-pump beating heart group. The level of vascular adhesion molecule dropped significantly during the operation but was elevated 4 hours (P =.026) after the operation in the on-pump beating heart group.

CONCLUSION

The use of cardiopulmonary bypass alone without global myocardial ischemia secondary to aortic crossclamping and cardioplegic cardiac arrest can trigger intense inflammatory responses.

Assessing Life Expectancies of Institutionalized Older Persons in Hong Kong

BACKGROUND

In Hong Kong, it has been projected that, by the year 2010, there will be 0.86 million persons aged 65 or older. The demand for residential care places continues to rise. Information on the survival of older persons will allow better management of care in institutional settings.

OBJECTIVE

The Weibull model was developed to predict the 18-month survival of a group of Chinese nursing home residents.

METHODS

In this prospective cohort study, 590 older residents from four nursing homes with different levels of care were enrolled. The main outcome measure was survival at 18 months. Information on subject demographics, clinical data and disability levels as measured by the Patient Assessment Instrument (PAI) was collected at baseline. Life expectancies were derived from accelerated failure time models.

RESULTS

Independent predictors of decreased survival derived from the Weibull model included increased age, male gender, diagnosis of cancer, presence of malnutrition and functional dependence. Significant interaction was observed between male gender and PAI score. The goodness of fit of the model was satisfactory.

CONCLUSIONS

From this study, the model for predicting life expectancy in nursing home residents can assist policy makers in planning long-term care. It can also guide clinicians to make more appropriate management decisions for their older patients.

Estimating geriatric patient's body weight using the knee height caliper and mid-arm circumference in Hong Kong Chinese

The use of the knee height caliper is a convenient way to estimate a patient's body weight. However, the equation devised to estimate an individual's body weight was specifically designed for Caucasians and Blacks. Therefore, this study is to assess the suitability of the knee height caliper among Chinese geriatric patients residing in Hong Kong. Over a six-month period, all geriatric patients from an acute care hospital and private nursing home in the Kwun Tong were recruited into the study. Only patients/residents that were considered unstable with ascites; low blood pressure; on cardiac monitors or had respiratory difficulties were excluded. Measurements from the knee height caliper and mid-arm muscle circumference of the patients were necessary for estimating their body weights. The actual body weights measured with calibrated bed, chair or portable scales was compared with the calculated body weights from the equation. A comparison of the mean and linear regression was performed for analysis of the results. A total of 300 geriatric patients (200 females and 100 males) were recruited. The mean MAC and knee height results were as follows: 25.1 cm (SD 3.9) for females and 26.2 cm (SD 3.2) for males; and 45.75 cm (SD 2.09) for females and 48.98 cm (SD 2.09) for males respectively. The mean difference among the male group was 0.4222 (95% CI: -0.54, 1.39) with a mean estimated body weight of 58.1 kg (SD 10.1) and a mean actual body weight of 57.7 kg (SD 9.9). The mean difference among the female group was 2.9649 (95% CI: 2.30, 3.63) with a mean estimated body weight of 51.6 kg (SD 10.9) and a mean actual body weight of 48.6 kg (SD 10.1). A new equation devised from the data is as follows: Chinese males (over 60 years of age) (R-square -0.81) Weight = [knee height (cm) x 0.928 + mid-arm circumference (cm) x 2.508 - age (years) x 0.144] - 42.543 +/-9.9kg of actual weight for 95% of Chinese males; Chinese females (over 60 years of age) (R-square - 0.82) Weight (kg) = [knee height (cm) x 0.826 + mid-arm circumference (cm) x 2.116 - age (years) x 0.133] - 31.486 +/-10.1kg of actual weight for 95% of Chinese females. The results showed that the mean estimated body weight calculated from the knee height equation (for Caucasians) was significantly larger than the mean actual body weight for the Chinese subjects. This study suggests that the knee height caliper is a useful tool for estimating the body weights. However, a multi-center study is necessary to validate the new equation for the elderly Chinese population.

Health belief and health practice in contact lens wear--a dichotomy?

PURPOSE

To establish if the hygiene practice of contact lens wearers (CLWs) can be influenced by "health belief."

METHODS

A nested case-control study based on questionnaires was conducted in Hong Kong over a 17-month period between 45 CLW patients with microbial keratitis and 135 matched asymptomatic CLW volunteer controls.

RESULTS

There was no significant difference between keratitis patients and controls (volunteers) in the perceived benefits of optometrists' instructions generally. When asked specifically, however, keratitis patients scored significantly higher than controls in the perceived benefit of checking initially with the optometrist for the correct method of lens cleaning. Contact lens wearing patients with keratitis were confident that their care of lenses would prevent complications, but this probably represented over confidence in themselves. Patients also scored significantly more neutrally in self-efficacy. Surprisingly, patients were significantly less likely to perceive the cost of lens care as a barrier but did not use their disinfecting regimes properly.

CONCLUSION

We have found that CLWs still regard their eye care professional as being the most important for giving them advice on hygiene. There is considerable opportunity to educate and influence CLWs in ways to prevent infection, but the advice given must be correct. Continuing education of optometrists is also required.

Effects of Blood-Processing Protocols on Fetal and Total DNA Quantification in Maternal Plasma

Background: Recently, apoptotic cells have been found in plasma obtained by centrifugation of blood from pregnant women, raising the question of what constitutes plasma and whether plasma is truly cell free. We compared the effects of different blood-processing protocols on the quantification, DNA composition, and day-to-day fluctuation of fetal and total DNA in maternal plasma.

Methods: Blood samples were collected from healthy pregnant women. The blood sample from each individual was simultaneously processed by different means, including the following: Percoll separation, centrifugation, microcentrifugation, and filtration. The resulting plasma aliquots were subjected to real-time quantitative amplification of the β-globin (for total DNA) and SRY (for fetal DNA) genes. The differences in the β-globin and SRY DNA concentrations and the degree of variation between the various plasma aliquots were assessed statistically.

Results: Different protocols of blood processing significantly affected the quantification and the day-to-day fluctuation of total (P &lt;0.001), but not fetal (quantification, P = 0.336; fluctuation, P = 0.206), DNA in maternal plasma. The quantitative difference could be attributed to the fact that efficacies of different protocols for generating cell-free plasma vary. Processing blood samples by centrifugation followed by filtration or microcentrifugation is effective in producing cell-free plasma.

Conclusions: Standardization in plasma-processing protocols is needed for maternal plasma DNA analysis, especially for quantification of total DNA in maternal plasma. Such preanalytic factors may also affect other applications of plasma DNA analysis.

A Microcomputer-Based Infant Pulmonary Function System for Determination of Forced and Passive Expiratory Flow-Volume Curves: Technical Aspects

The development of an infant pulmonary function system for medical application is important in providing a clear in depth understanding of the physical and mechanical functioning of the lung of an infant. Forced and passive expiratory flow-volume curves convey useful information about pulmonary functions. This information can be used to monitor the early development of the lungs and detect any respiratory disorders in infants. Research into various techniques to obtain these curves has shown significant progress. In this study, a microcomputer-based system was designed and built to enable these techniques to be more efficiently and accurately implemented. This paper describes the system developed to automate the test procedures, obtain the flow-volume curves, analyse test data and store results conveniently. Lastly, system performance is also discussed.