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Biomedical subjects

K K Cheng

Publications and source records attributed to K K Cheng.

At least 37 records · Page 2Linked to original sources
PubMed2003

Social deprivation and breast cancer.

BACKGROUND: This cross-sectional study was carried out in a population-based setting in Worcestershire to investigate the relationship between social deprivation and other potential prognostic factors. METHODS: A total of 762 female patients diagnosed with primary breast cancer between 1 January 1998 and 31 December 1999 were selected. Breast cancer included all new cases of primary invasive breast cancer and ductal carcinoma in situ. A total of 753 patients were matched by their postcode of residence to enumeration district Townsend score and then divided into three groups based on Townsend quintiles (affluent n = 478; middle n = 157; deprived n = 118). Main outcome measures were relationships between social deprivation and tumour type, stage at presentation, oestrogen receptor status, tumour grade and treatment type. RESULTS: Compared with the most deprived women, affluent women were less likely to present with invasive ductal tumours (70.8 per cent versus 85.9 per cent, chi2 linear trend = 6.757, p = 0.009), tumours of higher grade (36.0 per cent versus 44.7 per cent, chi2 linear trend = 4.201, p = 0.040), and oestrogen receptor negative tumours (22.4 per cent versus 33.3 per cent, chi2 linear trend = 3.501, p = 0.061). There was no significant difference in stage or tumour size at presentation between deprivation groups. More deprived women with invasive tumours of less than 20 mm maximum diameter were significantly more likely to have mastectomies than affluent women (47.8 per cent versus 32.1 per cent, chi2 linear trend = 4.091, p = 0.043). CONCLUSIONS: This study suggests that level of social deprivation is associated with tumour type, grade and oestrogen receptor status. There was also a suggestion that increased level of deprivation was associated with increased risk of potentially unnecessary mastectomies.

Aged↗
PubMed2003

The importance of social sources of cigarettes to school students.

OBJECTIVE: To discover the importance of social sources of tobacco to young people as opposed to commercial sources; to describe the peer market for cigarettes in schools and the consequences for young people of their involvement in it. STUDY DESIGN: Cross sectional questionnaire survey, one-to-one interviews, and focus groups. SETTING: Seven schools in Birmingham, UK. SUBJECTS: All students in two randomly selected classes from each school completed the questionnaire, and never smokers, occasional smokers, and regular smokers were interviewed. RESULTS: Two thirds of occasional smokers and one quarter of regular smokers obtained cigarettes socially, mostly for free. A few smokers regularly bought their cigarettes from others. Among friendship groups, both smokers and non-smokers were involved in the exchange of cigarettes, often for money, which is a common activity. A few young people use the selling of cigarettes to fund their own smoking. Some young people, smokers and non-smokers, are involved in semi-commercial selling of cigarettes. All school students are aware of where to purchase cigarettes from non-friends, which is only used "in emergency" because of the high price. One school had a strong punishment policy for students caught with cigarettes. In this school, more people bought singles from the peer market and the price was higher. CONCLUSIONS: The passing and selling of cigarettes in school is a common activity, which from the young persons perspective, ensures that all share cross counter purchases. A few people are prepared to use the peer market for monetary gain and it appears to be responsive to external conditions. The peer market might mean that efforts to control illegal sales of cigarettes are not as effective as hoped.

Adolescent↗
PubMed2003

A cluster randomised controlled trial of smoking cessation in pregnant women comparing interventions based on the transtheoretical (stages of change) model to standard care.

OBJECTIVES: To evaluate the effectiveness in helping pregnant women stop smoking of two interventions (Pro-Change for a healthy pregnancy) based on the transtheoretical model of behaviour change (TTM) compared to current standard care. DESIGN: Cluster randomised trial. SETTING: Antenatal clinics in West Midlands, UK general practices. PARTICIPANTS: 918 pregnant smokers INTERVENTIONS: 100 general practices were randomised into the three trial arms. Midwives in these practices delivered three interventions: A (standard care), B (TTM based self help manuals), and C (TTM based self help manuals plus sessions with an interactive computer program giving individualised smoking cessation advice). MAIN OUTCOME MEASURES: Biochemically confirmed smoking cessation for 10 weeks previously, and point prevalence abstinence, both measured at 30 weeks of pregnancy and 10 days after delivery. RESULTS: There were small differences between the TTM arms. Combining the two arms, the odds ratios at 30 weeks were 2.09 (95% confidence interval (CI) 0.90 to 4.85) for 10 week sustained abstinence and 2.92 (95% CI 1.42 to 6.03) for point prevalence abstinence relative to controls. At 10 days after delivery, the odds ratios were 2.81 (95% CI 1.11 to 7.13) and 1.85 (95% CI 1.00 to 3.41) for 10 week and point prevalence abstinence respectively. CONCLUSIONS: While there is a small borderline significant increase in quitting in the combined intervention arms compared with the controls, the effect of the intervention is small. At 30 weeks gestation and at 10 days postnatal, only about 3% of the intervention groups achieved sustained cessation, with numbers needed to treat of 67 (30 weeks of gestation) and 53 (10 weeks postnatal) for one additional woman to achieve sustained confirmed cessation. Given also that the intervention was resource intensive, it is of doubtful benefit.

Adolescent↗
PubMed2002

Exposure to power frequency electric fields and the risk of childhood cancer in the UK.

The United Kingdom Childhood Cancer Study, a population-based case-control study covering the whole of Great Britain, incorporated a pilot study measuring electric fields. Measurements were made in the homes of 473 children who were diagnosed with a malignant neoplasm between 1992 and 1996 and who were aged 0-14 at diagnosis, together with 453 controls matched on age, sex and geographical location. Exposure assessments comprised resultant spot measurements in the child's bedroom and the family living-room. Temporal stability of bedroom fields was investigated through continuous logging of the 48-h vertical component at the child's bedside supported by repeat spot measurements. The principal exposure metric used was the mean of the pillow and bed centre measurements. For the 273 cases and 276 controls with fully validated measures, comparing those with a measured electric field exposure >/=20 V m(-1) to those in a reference category of exposure <10 V m(-1), odds ratios of 1.31 (95% confidence interval 0.68-2.54) for acute lymphoblastic leukaemia, 1.32 (95% confidence interval 0.73-2.39) for total leukaemia, 2.12 (95% confidence interval 0.78-5.78) for central nervous system cancers and 1.26 (95% confidence interval 0.77-2.07) for all malignancies were obtained. When considering the 426 cases and 419 controls with no invalid measures, the corresponding odds ratios were 0.86 (95% confidence interval 0.49-1.51) for acute lymphoblastic leukaemia, 0.93 (95% confidence interval 0.56-1.54) for total leukaemia, 1.43 (95% confidence interval 0.68-3.02) for central nervous system cancers and 0.90 (95% confidence interval 0.59-1.35) for all malignancies. With exposure modelled as a continuous variable, odds ratios for an increase in the principal metric of 10 V m(-1) were close to unity for all disease categories, never differing significantly from one.

Adolescent↗
PubMed2002

Can the stages of change for smoking acquisition be measured reliably in adolescents?

BACKGROUND: was to examine the reliability of the algorithm. METHODS: As part of a randomized controlled trial, 3,930 adolescents completed a paper version of the algorithm questions and a differently worded computerized version on the same day: a parallel form reliability assessment. In a separate assessment, another group of 118 adolescents completed 2 identical paper versions of the same questionnaire 2 weeks apart: a test-retest reliability assessment. Kappa (kappa) for agreement for stage and the individual questions were calculated. Logistic regression was used to examine whether demographic characteristics, smoking status, and stage predicted agreement for stage. RESULTS: Kappa (95% confidence intervals) for stage was 0.57 (0.55-0.60) in the first assessment and 0.46 (0.28-0.63) in the second assessment, indicating moderate reliability. The question concerning trying smoking in the next 6 months was moderately reliable, but that concerning trying within the next thirty days was poorly reliable. Acquisition precontemplation was significantly more reliably coded than all other stages. Demographic characteristics did not predict reliability. CONCLUSIONS: The algorithm reliably allocates individuals into acquisition precontemplation, but for all other stages, its reliability is fair.

Adolescent↗
PubMed2002

Does smoking status influence the prognosis of bladder cancer? A systematic review.

OBJECTIVE: To summarize, in a systematic review, the evidence for the effect of stopping smoking on recurrence, cancer-specific and all cause-mortality among smokers with newly diagnosed bladder cancer. MATERIALS AND METHODS: Two electronic databases and the reference lists of identified primary studies and reviews were searched. Studies were included if a hazard ratio and its confidence intervals could be extracted. A predefined set of study characteristics was extracted which defined whether studies were giving valid prognostic data on the effects of smoking in reasonably homogenous cohorts. The results of studies were synthesized qualitatively. RESULTS: Fifteen relevant studies were identified; former and current smokers were combined in many studies. Many studies produced information on prognosis that was confounded by the mixing of incident and prevalent cases. Only three studies examined the influence of smoking on prognosis in only incident cases, most of whom had superficial disease. Of these, only one was of high quality. These three studies and the other 12 showed suggestive evidence that continued smoking or a lifetime of smoking constitutes a moderate risk factor for recurrence and death, and that stopping smoking could favourably change this. However, the evidence base for this is weak because of the methodological shortcomings and because most studies' results were not statistically significant. A life-table model showed that if stopping smoking altered the prognosis, the size of the benefit would be clinically worthwhile. CONCLUSION: There is suggestive evidence that stopping smoking might favourably alter the course of bladder cancer, but this is insufficient for clinicians to inform patients that doing so will improve their prognosis, and for providing specialized services to assist in stopping smoking to patients with bladder cancer.

Adult↗
PubMed2002

The risk of preterm delivery in women from different ethnic groups.

OBJECTIVE: To examine whether routinely measured variables explained the increased risk of preterm delivery in some UK ethnic groups. DESIGN: Cross sectional study of deliveries recorded in the Child Health Record System. SETTING: North Birmingham, UK. POPULATION: All North Birmingham women delivering singletons, 1994-1997 inclusive. METHOD: Logistic regression. MAIN OUTCOME MEASURES: Odds ratio (OR) and 95% confidence interval (CI) for preterm delivery, defined as less than 37 weeks, less than 34 weeks and less than 28 weeks, unadjusted and adjusted for maternal age, an area-based socio-economic status measure, and marital status, year of birth, fetal sex and past obstetric history. RESULTS: For Afro-Caribbean women, the ORs (95% CIs) were: for delivery less than 37 weeks, 1.44 (1.26-1.64) unadjusted and 1.22 (1.07-1.41) adjusted; for delivery less than 34 weeks, 1.55 (1.25-1.92) unadjusted and 1.29 (1.02-1.61) adjusted; for delivery less than 28 weeks, 1.66 (1.08-2.55) unadjusted and 1.32 (0.84-2.06) adjusted. For African women, the risk of delivery less than 37 weeks was not significantly raised; for delivery less than 34 weeks, the OR (95% CI) was 1.88 (0.99-3.58) unadjusted and 1.78 (0.93-3.40) adjusted; for delivery less than 28 weeks, the OR (95% CI) was 4.02 (1.60-10.12) unadjusted and 4.10 (1.66-10.16) adjusted. In Afro-Caribbeans, deprivation and marital status explained the differences between the unadjusted and adjusted ORs. There was a linear relation between deprivation and preterm delivery for all ethnic groups, except for Asians. CONCLUSIONS: Factors associated with deprivation and marital status explain about half of the excess of preterm births in Afro-Caribbeans, but not Africans. The risk of preterm delivery might not be related to deprivation in Asians.

Africa↗
PubMed2001

Risk factors for squamous cell carcinoma of the oesophagus in women: a case-control study.

Oesophageal cancer rates in women in the UK are more than 3 times higher than in most other European populations. A population-based matched case-control study of histologically confirmed squamous cell carcinoma of the oesophagus in women was carried out in 4 regions in England and Scotland. Interviews were carried out in hospital or at home and topics included: smoking; alcohol; tea and coffee consumption; medical and obstetric history; and diet. Response rates were 62% for cases and 65% for first-chosen controls. There were 159 case-control pairs. Significant results were found for: eating salads (odds ratio (OR) 0.42, 95% CI 0.20-0.92 in the highest quartile of consumption) and a light (as distinct from no) breakfast (OR 0.18, 95% CI 0.07 - 0.48) were protective; quantity of tea was a risk factor and there was a significant positive trend with temperature at which hot drinks were consumed (P = 0.03). Alcohol consumption was unrelated to risk, but there was a significant trend with years of smoking (P = 0.015). A protective effect of aspirin consumption was confined to the English centres (OR 0.08, 95% CI 0.01-0.56). Comparison with a parallel study of adenocarcinoma indicated a common protective effect of a healthy diet but otherwise distinct risk factors.

Aged↗
PubMed2001

Childhood cancer in the south Asian population of England (1990-1992).

Cancer incidence in 1990-92 among English south Asian (residents with ethnic origins in India, Pakistan or Bangladesh) and non-south Asian children is compared. Standardized incidence ratios show significant overall excesses in south Asians (131), largely due to higher rates in south Asian boys, and specific excesses for leukaemia (141), lymphoid leukaemia (141), lymphoma (172) and hepatic tumours (375). Aetiological investigation is required.

Adolescent↗
PubMed2001

Bristol, Shipman, and clinical governance: Shewhart's forgotten lessons.

During the past century, manufacturing industry has achieved great success in improving the quality of its products. An essential factor in this success has been the use of Walter A Shewhart's pioneering work in the economic control of variation, which culminated in the development of a simple yet powerful graphical method known as the control chart. This chart classifies variation as having a common cause or special cause and thus guides the user to the most appropriate action to effect improvement. Using six case studies, including the excess deaths after paediatric cardiac surgery seen in Bristol, UK, and the activities of general practitioner turned murderer Harold Shipman, we show a central role for Shewhart's approach in turning the rhetoric of clinical governance into a reality.

Adult↗
PubMed2001

The change-in-stage and updated smoking status results from a cluster-randomized trial of smoking prevention and cessation using the transtheoretical model among British adolescents.

BACKGROUND: The transtheoretical model (TTM) and computer technology are promising technologies for changing health behavior, but there is little evidence of their effectiveness among adolescents. METHOD: Four thousand two hundred twenty-seven Year 9 (ages 13-14) pupils in 26 schools were randomly allocated to control and 4,125 in 26 schools were allocated to TTM intervention. TTM pupils received three whole class lessons and three sessions with an interactive computer program. Control pupils received no special intervention. Positive change in stage and smoking status was assessed from a questionnaire completed at baseline, 1 year, and 2 years. Random effects logistic regression was used to compare the change in stage and smoking status between the arms. RESULTS: Eighty-nine percent of the TTM group and 89.3% of the control group were present at 1-year and 86.0 and 83.1%, respectively, were present at 2-year follow-up. The adjusted odds ratio (95% confidence interval) for positive stage movement in the TTM relative to control was 1.13 (0.91-1.41) at 1 year and 1.25 (0.95-1.64) at 2 years and for regular smoking was 1.14 (0.93-1.39) at 1 year and 1.06 (0.86-1.31) at 2 years. Subgroup analysis by initial smoking status revealed no benefit for prevention or cessation. CONCLUSIONS: The intervention was ineffective.

Adolescent↗
PubMed2001

Evaluation of an oral care protocol intervention in the prevention of chemotherapy-induced oral mucositis in paediatric cancer patients.

Oral mucositis is the most frequent and severe complication of chemotherapy in children with cancer that can aggravate the child's clinical condition and increase the risk of infection. This prospective comparative study was designed to determine the effectiveness of a preventive oral care protocol in reducing chemotherapy-induced oral mucositis in children with cancer. During an 8-month period, 42 children aged 6 to 17 years with haematological malignancies or solid tumours were evaluated. The 21 children who were included in the first 4-month period of the study constituted the control group. Another 21 children were enrolled in the subsequent 4 months and were assigned to the experimental group, in which they were given an oral care protocol intervention. The oral care protocol consisted of tooth brushing, 0.2% chlorhexidine mouth rinse and 0.9% saline rinse. Children in both groups were evaluated twice a week for 3 weeks. The incidence of ulcerative lesions, severity of oral mucositis and the related pain intensity were used as the main outcome variables. A 38% reduction in the incidence of ulcerative mucositis was found in children using the oral care protocol compared with children in the control group. The severity of oral mucositis (P=0.000002) and the related pain (P=0.0001) were significantly reduced with the intervention. These results support the preventive use of the oral care protocol in paediatric cancer patients who undergo chemotherapy for cancer treatment.

Adolescent↗
PubMed2001

Methicillin-resistant Staphylococcus aureus (MRSA): a community-based prevalence survey.

A prevalence survey of nasal methicillin-resistant Staphylococcus aureus (MRSA) carriage was undertaken on a random sample of adults (aged over 16) resident in the community in Birmingham, UK during 1998. Microbiological samples were taken from the anterior nares at the subjects' general practice or in their home. Information about risk factors for the acquisition of MRSA was obtained via a self-completed questionnaire. A 58% response rate (280/483) was achieved. The prevalence of nasal MRSA colonization was 1.5% [4/274, 95% confidence interval (CI) 0.03-2.9%]. Twenty-three per cent (63/274) of subjects were nasal carriers of S. aureus. Six per cent (4/63) of S. aureus isolates were MRSA and 2 of the 4 MRSA carriers reported previous contact with health facilities. The prevalence of MRSA colonization in the general adult population in Birmingham appears to be low.

Adolescent↗