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Biomedical subjects

L D Ritchie

Publications and source records attributed to L D Ritchie.

At least 19 recordsLinked to original sources

Impact of deprivation and rural residence on treatment of colorectal and lung cancer.

For common cancers, survival is poorer for deprived and outlying, rural patients. This study investigated whether there were differences in treatment of colorectal and lung cancer in these groups. Case notes of 1314 patients in north and northeast Scotland who were diagnosed with lung or colorectal cancer in 1995 or 1996 were reviewed. On univariate analysis, the proportions of patients receiving surgery, chemotherapy and radiotherapy appeared similar in all socio-economic and rural categories. Adjusting for disease stage, age and other factors, there was less chemotherapy among deprived patients with lung cancer (odds ratio 0.39; 95% confidence intervals 0.16 to 0.96) and less radiotherapy among outlying patients with colorectal cancer (0.39; 0.19 to 0.82). The time between first referral and treatment also appeared similar in all socio-economic and rural groups. Adjusting for disease stage and other variables, times to lung cancer treatment remained similar, but colorectal cancer treatment was quicker for outlying patients (adjusted hazard ratio 1.30; 95% confidence intervals 1.03 to 1.64). These findings suggest that socio-economic status and rurality may have a minor impact on modalities of treatment for colorectal and lung cancer, but do not lead to delays between referral and treatment.

Aged↗

Rural and urban differences in stage at diagnosis of colorectal and lung cancers.

There is evidence that patients living in outlying areas have poorer survival from cancer. This study set out to investigate whether they have more advanced disease at diagnosis. Case notes of 1323 patients in north and northeast Scotland who were diagnosed with lung or colorectal cancer in 1995 or 1996 were reviewed. Of patients with lung cancer, 42% (69/164) living 58 km or more from a cancer centre had disseminated disease at diagnosis compared to 33% (71/215) living within 5 km. For colorectal cancer the respective figures were 24% (38/161) and 16% (31/193). For both cancers combined, the adjusted odds ratio for disseminated disease at diagnosis in furthest group compared to the closest group was 1.59 (P = 0.037). Of 198 patients with non-small-cell lung cancer in the closest group, 56 (28%) had limited disease (stage I or II) at diagnosis compared to 23 of 165 (14%) of the furthest group (P = 0.002). The respective figures for Dukes A and B colorectal cancer were 101 of 196 (52%) and 67 of 172 (39%) (P = 0.025). These findings suggest that patients who live remote from cities and the associated cancer centres have poorer chances of survival from lung or colorectal cancer because of more advanced disease at diagnosis. This needs to be taken into account when planning investigation and treatment services.

Aged↗

Ethnic issues in the epidemiology of childhood obesity.

Childhood obesity may be seen as a marker for high-risk dietary and physical inactivity practices. Recent increases in the prevalence of overweight and obesity among American children are not limited to one age, gender, or ethnic group, which suggests that unique behaviors of the members of various racial or ethnic subgroups of the population are unlikely to be the major contributing factors. Rather, it seems that environmental changes promoting increased energy intake and decreased energy output are occurring and have widespread impact on children from various backgrounds. Although no ethnic group is immune from the current shift in energy balance, differential rates of overweight seem to exist among ethnic groups. National probability samples of African-American, Hispanic, and white children in the United States provide clear evidence that white children are at lower risk for childhood overweight than are African-American or Hispanic children. Of concern is the lack of national data on the prevalence of overweight and obesity for Native-American and Asian-American groups. Also of concern is the aggregation of racial and ethnic subgroups, which may render prevalence rates meaningless. This possibility is clearly true with some surveys of weight status that combine diverse populations, such as Asians and Pacific Islanders, into one group. The high rates of obesity in African-American, Hispanic, and Native-American children are of concern. Although parental SES is associated inversely with childhood obesity among whites, higher SES does not seem to protect African-American and Hispanic children against obesity. In these groups, childhood obesity does not seem to be associated significantly with parental income and education. Health consequences of childhood obesity include a higher prevalence of type 2 diabetes and an increased risk for adverse levels of lipids, lipoproteins, and blood pressure. The effects of recently reported unprecedented levels of childhood overweight on subsequent risk for obesity in middle age are not known until future longitudinal data can be collected. It seems likely, however, that future health consequences of current early and severe childhood obesity will be staggering. Funding for adult follow-up of longitudinal studies of high-risk African American, Hispanic, and Native-American children is needed urgently to provide information on the long-term effects of childhood obesity. Halting the obesity epidemic is a formidable task, but the success in recent decades of drastically reducing childhood undernutrition offers hope and should spur similar action and leadership efforts. Promotion of efforts to reduce excess caloric intake with efforts to increase energy expenditure should receive paramount attention in the design of health programs. Given the relatively few published obesity-prevention and treatment studies that are designed to address specific cultural issues, it is important to promote the development of culturally appropriate intervention strategies that are shown to be effective among youth of diverse backgrounds. Although the dietary and activity goals will be similar, parental, family, and community messages and techniques grounded in cultural traditions and norms will be different for each ethnic group. This approach is crucial in the United States, a country with an increasingly diverse population.

Black or African American↗

Population implications of lipid lowering for prevention of coronary heart disease: data from the 1995 Scottish health survey.

OBJECTIVE: To determine the proportion of the population, firstly, with cholesterol >/= 5.0 mmol/l and, secondly, with any cholesterol concentration, who might benefit from statin treatment for the following: secondary prevention of coronary heart disease (CHD); primary prevention at CHD risk 30%, 20%, 15%, and 6% over 10 years; and primary prevention at projected CHD risk 20% over 10 years (CHD risk at age 60 years if actual age < 60 years). SUBJECTS: Random stratified sample of 3963 subjects aged 35-64 years from the Scottish health survey 1995. RESULTS: For secondary prevention 7.8% (95% confidence interval (CI) 6.9% to 8.6%) of the population with cholesterol >/= 5.0 mmol/l would benefit from statins. For primary prevention, the prevalence of people at CHD risk 30%, 20%, 15%, and 6% over 10 years is 1.5% (95% CI 1.2% to 1.9%), 5.4% (95% CI 4.7% to 6.1%), 9.7% (95% CI 8.8% to 10.6%), and 32.9% (95% CI 31.5% to 34.4%), respectively. At projected CHD risk 20% over 10 years, 12.4% (95% CI 11.4% to 13.5%) would be treated with statins. Removing the 5.0 mmol/l cholesterol threshold makes little difference to population prevalence at high CHD risk. CONCLUSIONS: Statin treatment would be required for 7.8% of the population for secondary prevention. For primary prevention, among other factors, guidelines should take into account the number of patients needing treatment at different levels of CHD risk when choosing the CHD risk to target. The analysis supports a policy of targeting treatment at CHD risk 30% over 10 years as a minimum, as recommended in current British guidelines, with a move to treating at CHD risk 15% over 10 years as resources permit.

Adult↗

Dietary calcium and pregnancy-induced hypertension: is there a relation?

The evidence that calcium plays a role in the etiology, prevention, and treatment of pregnancy-induced hypertension (PIH) is reviewed. The precise factors involved in the pathogenesis of PIH are unclear, but several alterations in calcium metabolism have been identified. Epidemiologic data suggest an inverse correlation between dietary calcium intake and incidence of PIH. Although evidence suggests a possible beneficial effect of supplemental calcium, contradictions persist in clinical trials of pregnant women. Presently, there is insufficient evidence to support routine calcium supplementation of all pregnant women. However, high-risk groups, such as pregnant teens, populations with inadequate calcium intake, and women at risk of developing PIH, may benefit from consuming additional dietary calcium.

Calcium, Dietary↗

Prevalence of hip fracture risk factors in women aged 70 years and over.

We estimated the prevalence of common risk factors for hip fracture and the numbers needed to treat (NNT) to prevent a hip fracture in various high-risk population groups, using a postal risk factor survey of women aged 70 years and above from General Practices in Grampian and Yorkshire. Recorded risk factors included prior fracture of any type; low body weight; smoking; and family history of fracture. The prevalence rates of hip fracture risk factors were 34%, 7% and 11% for previous fracture, maternal hip fracture and smoking, respectively for the Grampian practices (low body weight being defined as falling in the lowest quartile) and 34%, 7% and 7% for a single practice in the York area. Applying previously published estimates of risk, NNT analysis produced a value of about 300 for women with no risk factors, whilst for women with three risk factors it was between 32 and 71, depending on which risk factors were present and assuming intervention reduced fracture rates by 30% or 50%. Groups of women at high risk of hip fracture can easily be identified in primary care and offered treatment, with realistic prospects of hip fracture prevention.

Aged↗

The diagnostic acceptability of low-bandwidth transmission for tele-ultrasound.

Ultrasound recordings were made of 100 consecutive patients attending for obstetric examination in Peterhead and 100 patients attending for non-obstetric examination in Aberdeen. Two identical video-conferencing machines were used to transmit and receive the original ultrasound images at data rates of 384 kbit/s and 128 kbit/s, thus producing a total of three tapes for each case. Four experienced observers, who were blinded to the transmission bandwidth, each viewed 300 examinations and decided whether the images were acceptable or not for diagnosis. Almost 100% of the obstetric ultrasound images on the original recordings were considered diagnostically acceptable, compared with 93% of the 384 kbit/s transmissions and 44% of the 128 kbit/s transmissions. Similarly, 99% of the non-obstetric ultrasound images were considered acceptable, compared with 87% of the 384 kbit/s transmissions and 21% of the 128 kbit/s transmissions. For the obstetric ultrasound images the intra-observer diagnostic agreement was 93% (kappa = 0.89) between the original and the 384 kbit/s transmissions, and 78% (kappa = 0.63) between the original and the 128 kbit/s transmissions. For the non-obstetric ultrasound images the respective intra-observer diagnostic agreements were 77% (kappa = 0.62) and 78% (kappa = 0.63). The quality of dynamic ultrasound images transmitted at 384 kbit/s was diagnostically acceptable, but was unsatisfactory at 128 kbit/s.

Female↗

Systematic review of cancer treatment programmes in remote and rural areas.

In an attempt to ensure high quality cancer treatment for all patients in the UK, care is being centralized in specialist centres and units. For patients in outlying areas, however, access problems may adversely affect treatment. In an attempt to assess alternative methods of delivering cancer care, this paper reviews published evidence about programmes that have set out to provide oncology services in remote and rural areas in order to identify evidence of effectiveness and problems. Keyword and textword searches of on-line databases (MEDLINE, EMBASE, HEALTHSTAR and CINAHL) from 1978 to 1997 and manual searches of references were conducted. Fifteen papers reported evaluations of oncology outreach programmes, tele-oncology programmes and rural hospital initiatives. All studies were small and only two were controlled, so evidence was suggestive rather than conclusive. There were some indications that shared outreach care was safe and could make specialist care more accessible to outlying patients. Tele-oncology, by which some consultations are conducted using televideo, may be an acceptable adjunct. Larger and more methodologically robust studies are justified and should be conducted.

Humans↗

Low-bandwidth tele-ultrasound.

We examined the acceptability and diagnostic accuracy of dynamic ultrasound images transmitted at 128 kbit/s and 384 kbit/s. The gold standard was the direct recording of 200 ultrasound examinations on video-tape. The taped images were later transmitted at both 128 kbit/s and 384 kbit/s and recorded, resulting in three tapes for each case. Four observers viewed each tape individually. Ninety per cent of images transmitted at 384 kbit/s were rated as diagnostically acceptable compared with 32% of images transmitted at 128 kbit/s. Diagnostic agreement between tapes transmitted at 384 kbit/s and the gold standard was 85%, compared with 78% for 128 kbit/s transmissions. Observers were not satisfied with low-bandwidth transmission of ultrasound images despite adequate diagnostic accuracy. Dynamic ultrasound images transmitted at 384 kbit/s were viewed as both diagnostically acceptable and accurate.

Electronics↗

Secondary prevention in coronary heart disease: baseline survey of provision in general practice.

OBJECTIVE: To determine secondary preventive treatment and habits among patients with coronary heart disease in general practice. DESIGN: Process of care data on a random sample of patients were collected from medical records. Health and lifestyle data were collected by postal questionnaire (response rate 71%). SETTING: Stratified, random sample of general practices in Grampian. SUBJECTS: 1921 patients aged under 80 years with coronary heart disease identified from pre-existing registers of coronary heart disease and nitrate prescriptions. MAIN OUTCOME MEASURES: Treatment with aspirin, beta blockers, and angiotensin converting enzyme inhibitors. Management of lipid concentrations and hypertension according to local guidelines. Dietary habits (dietary instrument for nutritional evaluation score), physical activity (health practice indices), smoking, and body mass index. RESULTS: 825/1319 (63%) patients took aspirin. Of 414 patients with recent myocardial infarction, 131 (32%) took beta blockers, and of 257 with heart failure, 102 (40%) took angiotensin converting enzyme inhibitors. Blood pressure was managed according to current guidelines for 1566 (82%) patients but lipid concentrations for only 133 (17%). 673 of 1327 patients (51%) took little or no exercise, 245 of 1333 (18%) were current smokers, 808 of 1264 (64%) were overweight, and 627 of 1213 (52%) ate more fat than recommended. CONCLUSION: In terms of secondary prevention, half of patients had at least two aspects of their medical management that were suboptimal and nearly two thirds had at least two aspects of their health behaviour that would benefit from change. There seems to be considerable potential to increase secondary prevention of coronary heart disease in general practice.

Adrenergic beta-Antagonists↗

Secondary prevention clinics for coronary heart disease: randomised trial of effect on health.

OBJECTIVE: To evaluate the effects of secondary prevention clinics run by nurses in general practice on the health of patients with coronary heart disease. DESIGN: Randomised controlled trial of clinics over one year with assessment by self completed postal questionnaires and audit of medical records at the start and end of the trial. SETTING: Random sample of 19 general practices in northeast Scotland. SUBJECTS: 1173 patients (685 men and 488 women) under 80 years with working diagnoses of coronary heart disease who did not have terminal illness or dementia and were not housebound. INTERVENTION: Clinic staff promoted medical and lifestyle aspects of secondary prevention and offered regular follow up. MAIN OUTCOME MEASURES: Health status measured by the SF-36 questionnaire, chest pain by the angina type specification, and anxiety and depression by the hospital anxiety and depression scale. Use of health services before and during the study. RESULTS: There were significant improvements in six of eight health status domains (all functioning scales, pain, and general health) among patients attending the clinic. Role limitations attributed to physical problems improved most (adjusted difference 8.52, 95% confidence interval 4.16 to 12. 9). Fewer patients reported worsening chest pain (odds ratio 0.59, 95% confidence interval 0.37 to 0.94). There were no significant effects on anxiety or depression. Fewer intervention group patients required hospital admissions (0.64, 0.48 to 0.86), but general practitioner consultation rates did not alter. CONCLUSIONS: Within their first year secondary prevention clinics improved patients' health and reduced hospital admissions.

Adult↗

A longitudinal study of calcium homeostasis during human pregnancy and lactation and after resumption of menses.

To clarify the role of the intestine, kidney, and bone in maintaining calcium homeostasis during pregnancy and lactation and after the resumption of menses, a longitudinal comparison was undertaken of 14 well-nourished women consuming approximately 1200 mg Ca/d. Measurements were made before conception (prepregnancy), once during each trimester of pregnancy (T1, T2, and T3), early in lactation at 2 mo postpartum (EL), and 5 mo after resumption of menses. Intestinal calcium absorption was determined from the enrichment of the first 24-h urine sample collected after administration of stable calcium isotopes. Bone mineral of the total body and lumbar spine was measured by dual-energy X-ray absorptiometry and quantitative computerized tomography, respectively. Twenty-four-hour urine and fasting serum samples were analyzed for calcium, calcitropic hormones, and biochemical markers of bone turnover. Despite an increase in calcium intake during pregnancy, true percentage absorption of calcium increased from 32.9+/-9.1% at prepregnancy to 49.9+/-10.2% at T2 and 53.8+/-11.3% at T3 (P < 0.001). Urinary calcium increased from 4.32+/-2.20 mmol/d at prepregnancy to 6.21+/-3.72 mmol/d at T3 (P < 0.001), but only minor changes in maternal bone mineral were detected. At EL, dietary calcium and calcium absorption were not significantly different from that at prepregnancy, but urinary calcium decreased to 1.87+/-1.22 mmol/d (P < 0.001) and trabecular bone mineral density of the spine decreased to 147.7+/-21.2 mg/cm3 from 162.9+/-25.0 mg/cm3 at prepregnancy (P < 0.001). Calcium absorption postmenses increased nonsignificantly to 36.0+/-8.1% whereas urinary calcium decreased to 2.72+/-1.52 mmol/d (P < 0.001). We concluded that fetal calcium demand was met by increased maternal intestinal absorption; early breast-milk calcium was provided by maternal renal calcium conservation and loss of spinal trabecular bone, a loss that was recovered postmenses.

Absorptiometry, Photon↗

Secondary prevention in coronary heart disease: a randomised trial of nurse led clinics in primary care.

OBJECTIVE: To evaluate whether nurse run clinics in general practice improve secondary prevention in patients with coronary heart disease. DESIGN: Randomised controlled trial. SETTING: A random sample of 19 general practices in northeast Scotland. PATIENTS: 1173 patients (685 men and 488 women) under 80 years with working diagnoses of coronary heart disease, but without terminal illness or dementia and not housebound. INTERVENTION: Nurse run clinics promoted medical and lifestyle aspects of secondary prevention and offered regular follow up. MAIN OUTCOME MEASURES: Components of secondary prevention assessed at baseline and one year were: aspirin use; blood pressure management; lipid management; physical activity; dietary fat; and smoking status. A cumulative score was generated by counting the number of appropriate components of secondary prevention for each patient. RESULTS: There were significant improvements in aspirin management (odds ratio 3.22, 95% confidence interval 2.15 to 4.80), blood pressure management (5.32, 3.01 to 9.41), lipid management (3.19, 2.39 to 4.26), physical activity (1.67, 1.23 to 2.26) and diet (1.47, 1.10 to 1.96). There was no effect on smoking cessation (0.78, 0.47 to 1.28). Of six possible components of secondary prevention, the baseline mean was 3.27. The adjusted mean improvement attributable to intervention was 0.55 of a component (0.44 to 0.67). Improvement was found regardless of practice baseline performance. CONCLUSIONS: Nurse run clinics proved practical to implement in general practice and effectively increased secondary prevention in coronary heart disease. Most patients gained at least one effective component of secondary prevention and, for them, future cardiovascular events and mortality could be reduced by up to a third.

Aged↗

Zinc absorption in women during pregnancy and lactation: a longitudinal study.

Zinc is essential for normal fetal growth and development and for milk production during lactation. The metabolic adjustments made in zinc utilization to meet these needs have not been described. The purpose of this study was to determine whether fractional zinc absorption (FZA) is altered during pregnancy and lactation and, if so, to determine whether the change is related to maternal zinc status, specifically, concentrations of zinc in plasma, erythrocytes, urine, and breast milk and dietary zinc intake. Thirteen women were studied at five time points: once preconception; at 8-10, 24-26, and 34-36 wk gestation; and once while they were lactating 7-9 wk postpartum. Zinc intake increased by 35 mumol/d (2.3 mg/d) from preconception to 34-36 wk (P = 0.04); it tended to decrease (P > 0.05) during lactation but did not return to the preconception level. The amount of zinc in breast milk averaged 2.0 mg/d at the lactation time point. FZA measured from urinary enrichments of two stable isotopes of zinc increased from 14% preconception to 25% during lactation (P = 0.023) but the increase to 19% at 34-36 wk gestation was not significant. No increase in FZA occurred in four women who took iron supplements during lactation. FZA was negatively correlated with plasma zinc concentration at 34-36 wk gestation and with urinary zinc excretion at all time points. The nearly twofold increase in zinc absorption during lactation was presumably in response to the demand for zinc to synthesize breast milk.

Adult↗