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K Ritchie

Publications and source records attributed to K Ritchie.

At least 19 recordsLinked to original sources
PubMed1992

A comparative study of the performance of screening tests for senile dementia using receiver operating characteristics analysis.

The discriminability of three types of test for the detection of senile dementia was assessed within a French sample of 155 normal elderly and 120 persons with mild or moderate senile dementia using Receiver Operating Characteristics (ROC) analysis. Results suggest that despite differences in the content of the three instruments, they are equally discriminant. Methods involving direct cognitive examination were found to lose discriminability in relation to milder forms of dementia, whereas an informant questionnaire was found to perform equally as well on cases of mild and moderate dementia. The informant questionnaire was also found to produce lower refusal rates and to be less influenced by the place of residence of the elderly person. The problem of selecting cut-off points according to the range of predicted prevalence rates of dementia for the general population is also discussed.

Aged↗
PubMed1992

Heterogeneity in senile dementia of the Alzheimer type: individual differences, progressive deterioration or clinical sub-types?

Although senile dementia of the Alzheimer type (SDAT) is commonly referred to as a disease involving global intellectual deterioration, clinical reports suggest the existence of variable patient profiles. A review of the clinical and biological research reporting heterogeneity in SDAT is summarized in terms of three descriptive models representing stage, compensation and sub-type hypotheses. Together the results suggest the existence of both quantitative and qualitative differences within a SDAT population. While the former may be partly attributable to the use in cross-sectional studies of persons at different stages of the disorder, qualitative differences in clinical evolution, variable patterns in regional cerebral blood flow, genetic markers and type of cognitive deficit strongly suggest the existence of different groups. This hypothesis requires verification by longitudinal neurological and psychometric studies of elderly persons with early dementia.

Aged↗
PubMed1992

The relationship between age and the prevalence of senile dementia: a meta-analysis of recent data.

A linear regression model derived from a meta-analysis of 13 epidemiological studies of senile dementia conducted since 1980, and employing internationally-known case-finding procedures, suggests a much lower general rate of dementia prevalence than has been previously estimated. An exponential increase with age is observed, with senile dementia prevalence diagnosed by Diagnostic and Statistical Manual (DSM-III) criteria doubling every 6 years and senile dementia of the Alzheimer's type (SDAT) every 4.2 years. Studies providing data for the oldest ages indicating a drop in the rate of increase after the age of 80 suggest that senile dementia may be age-related rather than ageing-related. Estimates derived from this model may provide a reasonably accurate means of estimating dementia prevalence in the general population. The limitations of this method for the purposes of prediction and studies of risk factors are discussed in relation to the hypothesized heterogeneity of senile dementia and possible cohort effects.

Age Factors↗
PubMed1991

Healthy life expectancy: evaluation of global indicator of change in population health.

OBJECTIVE: To review and evaluate the usefulness of healthy life expectancy as a global indicator of changes in a population's health. DESIGN: Review of all known studies to date from the United States, mainland Europe, Canada, and the United Kingdom that have used Sullivan's method of calculating disability free life expectancy. MAIN OUTCOME MEASURES: Life expectancy and disability free life expectancy. RESULTS: Over the past decade the average healthy life expectancy was 60 years for men and 64 for women, with the proportion of years of disability ranging from 11% to 21% in men and from 14% to 24% in women. At the age of 65 men could expect eight years of disability free life and women 10, with the life expectancy being respectively 14 and 19 years. The difference between the wealthiest and poorest income quintiles was 6.3 years in life expectancy and 14.3 in disability free life expectancy for men and 2.8 and 7.6 respectively for women. These results suggest that disparities in health are greater between social groups than between the sexes. Diseases affect mortality and morbidity differently. The order of importance for affecting life expectancy was circulatory disease, cancer, and accidents and for disability free life expectancy, circulatory disease, locomotor disorders, and respiratory disorders. CONCLUSIONS: Healthy life expectancy is a valuable index for the appreciation of changes in both the physical and the mental health states of the general population, for allocating resources, and for measuring the success of political programmes. Future calculations should also take into account the probability of recovery and thus extend the applicability of the indicator to populations in poor health rather than focusing on the well population.

Age Factors↗
PubMed1990

The French version of the Nottingham Health Profile. A comparison of items weights with those of the source version.

The efficient and reliable assessment of general community health requires the development of comprehensive and parsimonious measures of proven validity. The Nottingham Health Profile (NHP) has been demonstrated to be a reliable indicator of common expressions of discomfort and stress in the general population. The present paper describes its linguistic adaptation into French, the derivation of item weights by Thurstone's method of paired comparisons and the comparison of item weights across various sociodemographic groups. There is more similarity than variation on the valuation of the state of health explored by the NHP between the French and the British population as little inter-cultural or inter-linguistic variations were found. The differences in judgement of severity elicited across sociodemographic groups in the French sample cast some doubts on the relevance of general weights for use in population surveys.

Adolescent↗
PubMed1989

The little woman meets son of DSM-III.

The author discusses conceptual problems in psychiatry, illustrated by a debate over inclusion of a new disorder, masochistic personality disorder, in DSM-III-R, the manual of psychiatric diagnoses. While the DSM committee has attempted to avoid assumptions about theory and values in an attempt to be scientific, this has proved impossible, as theory is an integral part of scientific observation and values are a prerequisite for any judgement. The foundation for psychiatry cannot be theory-it can only be patient need.

Female↗
PubMed1989

Doppler ultrasound fetal velocimetry and its role in obstetrics.

Abnormal waveforms are seen in association with intrauterine growth restriction, but so far, using the Doppler technique as a screening test to identify unrecognized cases has been disappointing. The waveform changes appear to be associated with a reduced number of small fetal arterioles in the fetal placenta. The interpretation of waveforms is still uncertain and should not be used as a basis for management but rather to increase fetal surveillance by conventional means.

Female↗
PubMed1989

Screening for depression among the elderly in Israel: an assessment of the Short Geriatric Depression Scale (S-GDS).

Depression is a common source of distress in the elderly. Screening for depression allows for accurate diagnosis and treatment by clinicians and enables prevalence estimates to be used for monitoring morbidity and health services. A screening instrument is required that is both easily administered and has been validated among the heterogenous population of community-dwelling elderly in Israel. This study assesses the suitability of a short screening test with high face validity, the Short Geriatric Depression Scale (S-GDS), in a Jerusalem community sample (n = 285). The test yielded a 34% prevalence rate for depression, which is similar to rates found in community studies elsewhere. The screening test correctly classified 72% (95% confidence interval, 60 to 84%) of those with depression in a diagnosed subsample of 71 subjects. The specificity was only 57% (95% confidence interval, 44 to 70%) which was probably due to confounding with early dementia. The S-GDS was more likely to classify as depressed those with no formal education, those of Middle Eastern origin, and women. Higher levels of sensitivity and specificity can be obtained by calibrating, the cutoff score based on the level of education. The internal consistency of the test was adequate for the community sample as a whole, as well as among various demographic subgroups. The stability of test responses was also significant. Guidelines for the development of an instrument more appropriate for the Israeli population are suggested.

Aged↗
PubMed1988

Uterine artery flow velocity waveforms in normal and growth-retarded pregnancies.

Uterine artery flow velocity waveforms were measured by continuous-wave Doppler ultrasound in 15 normal pregnant women studied from midgestation until term. Results were analyzed by calculation of the pulsatility index and the systolic/diastolic blood velocity [corrected] ratio. Both indices decreased from 16 to 20 weeks (indicating a lowering of resistance) and thereafter remained stable until term. Resistance was lower when waveforms were recorded directly over the placenta or from the uterine artery close to the placenta. A group of women with severe intrauterine growth retardation were also studied. In preeclampsia, uterine artery resistance was increased in almost all patients. In pregnancies complicated by intrauterine growth retardation of non preeclamptic origin, a wide range of results was obtained.

Arteries↗
PubMed1988

A transmission line modelling approach to the interpretation of uterine Doppler waveforms.

An electrical analogue model of an artery that terminates into a vascular bed is presented. The model consists of an uniform transmission line that represents the artery and a load impedance that represents the vascular bed. The transmission line parameters are based on a well-established first-order approximation of the Navier-Stokes equations for fluid flow in distensible tubes. The model can be used to predict the incident and reflected components of both the arterial pressure and flow waveforms. In addition, it can predict the vessel diameter change and the mean blood velocity waveforms. In this study, the model was applied to the uterine artery so that the characteristics of the utero-placental circulation can be related to Doppler ultrasound recordings. It was found that the presence of the dicrotic notch in the uterine artery time-velocity waveform is the result of wave reflection and that a persistent notch past 20 weeks' gestation may be indicative of an abnormally high placental bed resistance. It is shown that the simulation results are consistent with the known physiological data and the clinically recorded uterine Doppler waveforms.

Arteries↗
PubMed1988

The screening of cognitive impairment in the elderly: a critical review of current methods.

The continued appearance of new screening tests for dementia suggests both the continuing need for a valid measure of pathological cognitive change and dissatisfaction with what is currently available. A brief review of current tests is presented which focuses on the major theoretical and methodological issues which have impeded the development of adequate screening instruments. Strategies for the management of such difficulties are also indicated, with a view to guiding prospective researchers in this field and increasing the critical perspective of those currently using these instruments.

Aged↗
PubMed1988

Umbilical and uterine artery blood flow velocities after vibratory acoustic stimulation.

Twelve healthy pregnant women between 37 and 41 weeks' gestational age were studied to determine the effects of external vibratory acoustic stimulation on the blood flow velocity waveform in the umbilical and uterine arteries. There was a significant decrease in umbilical peak-systolic/end-diastolic ratio during the first 5 minutes after stimulus after comparison with control ratios. Analysis of the frequency distribution of instantaneous fetal heart rate values during Doppler measurements suggested that the decrease in umbilical peak-systolic/end-diastolic ratio was due to fetal tachycardia rather than a change in the placental vascular resistance. The uterine artery peak-systolic/end-diastolic ratio was not altered after vibratory acoustic stimulation.

Acoustic Stimulation↗
PubMed1988

Professionalism, altruism, and overwork.

The author contends that overworking residents cannot be ethically justified. There is evidence that overwork is detrimental both to the resident and to the patient. In addition, the argument that working long hours is essential to maintain medicine's status as a profession is analyzed. The claim cannot be supported by definitions of professionalism. Although Flexner's definition does specify altruism as an essential component, it does not justify long working hours for residents. Altruism is obligatory in some limited cases, but only when it is required to fulfill some contractual obligation.

Altruism↗
PubMed1987

Umbilical artery Doppler blood flow studies in the preterm, small for gestational age fetus.

Umbilical artery Doppler studies were performed on the day of delivery in 15 singleton preterm pregnancies. In each case the fetus was significantly growth retarded on ultrasound examination and the attending obstetrician had made a decision to deliver the patient of the infant. Eight women had severe preeclampsia, three had mild chronic hypertension, and in four there was no recognized maternal disorder. Doppler studies were analyzed by use of the pulsatility index and the A/B ratio. In 14 of the 15 cases both were markedly abnormal. Three early neonatal deaths occurred. A positive correlation was found between the degree of abnormality of the pulsatility index and A/B ratio and a poor neonatal outcome (p less than 0.001 and p less than 0.02). Umbilical artery Doppler studies were not helpful in differentiating between intrinsic and extrinsic causes of growth retardation but seemed to identify the pregnancy at increased risk of a poor neonatal outcome.

Adult↗
PubMed1987

Umbilical artery flow velocity waveforms and the placental vascular bed.

Umbilical artery Doppler studies were performed close to delivery in 17 women (seven with healthy pregnancies and 10 complicated by intrauterine growth retardation), and results were analyzed by calculating the pulsatility index. In each case the placenta was examined histologically, and the small arteries and arterioles were counted in the tertiary stem villi. A highly significant negative linear relationship was found between pulsatility index and mean small arterial vessel count per field (r = 0.71, p less than 0.01). This suggests that when the pulsatility index is raised (indicating increased resistance), one possible explanation may be obliteration of small placental arteries.

Arteries↗
PubMed1979

Prematurity.

Perinatal epidemiologists no longer speak much of "prematurity". Instead the World Health Organization recommends that infants born before 37 completed weeks of gestation should be designated "preterm" and those of birthweight less than 2500 g "low birthweight". Both definitions have obvious drawbacks--the former because menstrual dates are often unknown or unreliable, the latter because it does not separate preterm from small-for-gestational-age infants. Whatever the classification of these small infants there is no dispute about their high mortality and morbidity; in the United Kingdom they account for over two-thirds of first-week deaths.

Female↗