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M Knapp

Publications and source records attributed to M Knapp.

At least 127 records · Page 7Linked to original sources
PubMed1998

Evaluation of a restricted likelihood ratio test for mapping quantitative trait loci with extreme discordant sib pairs.

Risch and Zhang recently proposed to use extreme discordant sib pairs for mapping quantitative trait loci. Here, it is shown that the set of genetically possible distributions of the number of marker alleles in such sib-pairs is described by two inequalities. Thus, a likelihood ratio test analogous to Holmans's possible triangle test for affected sib pairs can be defined. The performance of this test is compared to the mean test considered by Risch and Zhang. For most of the genetic models considered, the mean test is slightly more powerful than the restricted likelihood ratio test. However, for models with a rare recessive gene (or equivalently a common dominant gene), the restricted likelihood ratio test is much more powerful.

Alleles↗
PubMed1998

[The costs of schizophrenia].

Schizophrenia is regarded as the most expensive mental illness because of its specific symptoms and characteristics (e.g. early onset, often chronic course, high rates of readmission to hospital treatment, high rate of disabilities and extensive rehabilitative interventions), which prove to be extremely costly. Despite this, studies on the financial aspects of schizophrenia or the provision of care for schizophrenic patients has become an issue of psychiatric research only since the beginning of the reform of mental healthcare. Early cost studies had been conducted in the United States (US) during the fifties. Since then, they have grown in number not only in the US and in Great Britain, but also on the Continent of Europe. On an international level, comprehensive literature concerning methodology has attempted to establish cost studies as an integral part of mental health services research. Germany, however, is far behind international developments. Although the fundamental lack of empirical data on costs both in psychiatry as a whole and in schizophrenia had already been ascertained in a large national survey called "Psychiatrie-Enquête" in the mid-seventies, little has changed since then. One reason for these possibly great methodological problems is associated with the assessment of cost data in fragmented community mental health care networks, which in Germany include the additional obstacle--unlike abroad--of non-availability of access to data from case registers. Psychiatric case registers are not permitted in Germany because of very strict data protection laws. Despite the problems in methodology, there is an urgent need in Germany to remedy the lack of cost data for schizophrenic-patient care. The pressure of curbing costs in health care will probably force the German mental health care services to provide detailed cost data with regular reports in the future.

Humans↗
PubMed1998

A gene for universal congenital alopecia maps to chromosome 8p21-22.

Complete or partial congenital absence of hair (congenital alopecia) may occur either in isolation or with associated defects. The majority of families with isolated congenital alopecia has been reported to follow an autosomal-recessive mode of inheritance (MIM 203655). As yet, no gene has been linked to isolated congenital alopecia, nor has linkage been established to a specific region of the genome. In an attempt to map the gene for the autosomal recessive form of the disorder, we have performed genetic linkage analysis on a large inbred Pakistani family in which affected persons show complete absence of hair development (universal congenital alopecia). We have analyzed individuals of this family, using >175 microsatellite polymorphic markers of the human genome. A maximum LOD score of 7.90 at a recombination fraction of 0 has been obtained with locus D8S258. Haplotype analysis of recombination events localized the disease to a 15-cM region between marker loci D8S261 and D8S1771. We have thus mapped the gene for this hereditary form of isolated congenital alopecia to a locus on chromosome 8p21-22 (ALUNC [alopecia universalis congenitalis]). This will aid future identification of the responsible gene, which will be extremely useful for the understanding of the biochemistry of hair development.

Alopecia↗
PubMed1998

Support for a chromosome 18p locus conferring susceptibility to functional psychoses in families with schizophrenia, by association and linkage analysis.

The action of antipsychotic drugs on dopamine receptors suggests that dopaminergic signal transmission may play a role in the development of schizophrenia. We tested eight candidate genes (coding for dopamine receptors, the dopamine transporter, and G-proteins) in 59 families from Germany and Israel, for association. A P value of .00055 (.0044 when corrected for the no. of markers tested) was obtained for the intronic CA-repeat marker G-olfalpha on chromosome 18p. The value decreased to .000088 (.0007) when nine sibs with recurrent unipolar depressive disorder were included. Linkage analysis using SSLP markers densely spaced around G-olfalpha yielded a maximum two-point LOD score of 3.1 for a marker 0.5 cM distal to G-olfalpha. Multipoint analysis under the assumption of heterogeneity supported this linkage-whether the affected pheotype was defined narrowly or broadly-as did nonparametric linkage (NPL). In 12 families with exclusively maternal transmission of the disease, the NPL value also supported linkage to this marker. In order to test for association/linkage disequilibrium in the presence of linkage, the sample was restricted to independent offspring. When this sample was combined with 65 additional simplex families (each of them comprising one schizophrenic offspring and his or her parents), the 124-bp allele of G-olfalpha was transmitted 47 times and was not transmitted 21 times (P=.009). These results suggest the existence, on chromosome 18p, of a potential susceptibility locus for functional psychoses.

Chromosomes, Human, Pair 18↗
PubMed1998

Collaborating for improvement in health professions education.

Continual improvement efforts have been slower in health professions education than in health care delivery. This article identifies the lessons learned by teams working in an Interdisciplinary Professional Education Collaborative in overcoming barriers to carrying out continual improvement efforts in these educational organizations.

Competency-Based Education↗
PubMed1998

Public, private and voluntary residential mental health care: is there a cost difference?

OBJECTIVES: To determine how public (NHS or local government), private (for-profit) and voluntary (non-profit) providers of residential mental health care compare. Do they support different clienteles? And do their services cost different amounts? METHODS: Based on a cross-sectional survey of residential care facilities and their residents in eight English and Welsh localities, the characteristics and costs of care in the different sectors (NHS, local government, private, voluntary) were compared. Variations in cost were examined in relation to residents' characteristics using multiple regression analyses, which also allowed standardisation of results before making inter-sectoral comparisons. RESULTS: Private and voluntary providers of residential care support different clienteles from the public sector. The patterns of inter-sectoral cost differences vary between London and non-London localities. In London, voluntary sector facilities may be more cost-efficient than the other sectors, but local government/private sector comparisons show no consistent difference. Outside London, the results suggest clear cost advantages for the private and voluntary sectors over the local government sector. CONCLUSIONS: Private and voluntary providers may have some economic advantages over their public counterparts. However, outcomes for residents were not studied, leaving unanswered the question of comparative cost-effectiveness.

Community Mental Health Services↗
PubMed1998

Cost-effectiveness evaluation of compliance therapy for people with psychosis.

BACKGROUND: Non-compliance rates with antipsychotic medication can be high, and the personal and societal costs are considerable. A new psychological intervention, compliance therapy seeks to improve compliance and patient outcomes and reduce treatment costs. METHOD: A randomised controlled study examined the cost-effectiveness of compliance therapy compared to non-specific counselling over 18 months for 74 people with psychosis admitted as inpatients at the Maudsley Hospital. Bivariate and multivariate analyses were conducted to test for differences and to explore inter-patient cost variations. RESULTS: Compliance therapy is more effective and is no more expensive. Consequently, compliance therapy is more cost-effective than non-specific counselling at six, 12 and 18 months. CONCLUSIONS: There are compliance, outcome and cost-effectiveness arguments in favour of compliance therapy in preference to non-specific counselling.

Adult↗
PubMed1998

Home-based versus hospital-based care for serious mental illness. Controlled cost-effectiveness study over four years.

BACKGROUND: The Daily Living Programme (DLP) offered intensive home-based care with problem-centred case management for seriously mentally ill people facing crisis admission to the Maudsley Hospital, London. The cost-effectiveness of the DLP was examined over four years. METHOD: A randomised controlled study examined cost-effectiveness of DLP versus standard in/out-patient hospital care over 20 months, followed by a randomised controlled withdrawal of half the DLP patients into standard care. Three patient groups were compared over 45 months: DLP throughout the period, DLP for 20 months followed by standard care, and standard care throughout. Bivariate and multivariate analyses were conducted (the latter to standardise for possible inter-sample differences stemming from sample attrition and to explore sources of within-sample variation). RESULTS: The DLP was more cost-effective than control care over months 1-20, and also over the full 45-month period, but the difference between groups may have disappeared by the end of month 45. CONCLUSIONS: The reduction of the cost-effectiveness advantage for home-based care was perhaps partly due to the attenuation of DLP care, although sample attrition left some comparisons under-powered.

Adolescent↗
PubMed1998

Economic burden of drug dependency. Social costs incurred by drug users at intake to the National Treatment Outcome Research Study.

BACKGROUND: The use of illegal drugs is seen as a major social problem. The social costs can be high. METHODS: Self-report data from interviews at intake to the National Treatment Outcome Research Study (NTORS) for 1075 drug users and cost data from various sources were used to estimate criminal behaviour and health and addiction service costs for a 12-month period. Multivariate statistical analysis was used to analyse cost variations. RESULTS: Total costs for one year for the drug users amounted to over 12 million Pounds, the majority attributable to self-reported criminal behaviour. Social costs were positively related to a variety of factors including instability in living circumstances, amount of heroin used and whether or not drugs were taken intravenously. CONCLUSIONS: The study clearly demonstrates the economic and social burden associated with heavy drug users and highlights the need for further investigations into the costs and benefits of policies that can reduce these social costs.

Age Factors↗
PubMed1997

Evidence for DYT7 being a common cause of cervical dystonia (torticollis) in Central Europe.

Adult-onset focal idiopathic torsion dystonias (AFITD), such as torticollis, have a prevalence similar to that of multiple sclerosis and usually seem sporadic. Only recently has one large AFITD pedigree "K" with autosomal dominant inheritance and reduced penetrance from Northwest Germany provided the opportunity to identify a gene locus on chromosome 18p. We have now tested the relevance of this DYT7 gene locus in a collective of 18 nuclear AFITD families from Central Europe who were genotyped with chromosome 18p microsatellites. In three families, the affected relatives did not share a chromosome 18p haplotype, suggesting locus heterogeneity in AFITD. In the remaining 15 families, significant allelic association was observed for marker D18S1098. This result suggests that DYT7 is a common cause for AFITD at least in Central Europe, that many patients are descended from a common ancestor, and that the DYT7 gene is mapped in a 4.4 centimorgan subregion of chromosome 18p.

Adolescent↗
PubMed1997

Human 5-HT5A receptor gene: systematic screening for DNA sequence variation and linkage mapping on chromosome 7q34-q36 using a polymorphism in the 5' untranslated region.

Serotonin (5-hydroxytryptamine, 5-HT) is a neurotransmitter that mediates a wide range of sensory, motor, and cortical functions by activating multiple 5-HT receptor subtypes. In the present study we performed a systematic mutation scan of the complete coding region of the 5-HT5A receptor to explore its variability in the general population. Investigating 46 unrelated healthy subjects by single-strand conformation analysis no sequence changes of likely functional relevance were observed. The detection of a frequent G-->C substitution at position -19 was used for fine scale linkage mapping of the 5-HT5A gene. Employing a polymerase-chain-reaction based assay we genotyped 7 CEPH families (Centre d'Etude du Polymorphisme Humaine) and mapped the receptor to genetic markers on chromosome 7q34-q36.

Chromosome Mapping↗
PubMed1997

The "possible triangle" test for extreme discordant sib pairs.

For the analysis of quantitative traits in nuclear families, extreme discordant sib pairs proved to be more powerful than unselected sib pairs. Here, we present a test that makes use of selected pairs and, in addition, restricts the parameters of the identical-by-descent distribution analogously to the "possible triangle" for affected sib pairs. In the Problem 2A data, extreme discordant sib pairs are selected. The analysis allowed the detection of most simulated major genes.

Chromosome Mapping↗
PubMed1997

Sporadic focal dystonia in northwest Germany: molecular basis on chromosome 18p.

Idiopathic focal dystonia (IFD) is the most common form of idiopathic torsion dystonia in the Euroamerican population, with a prevalence of about 30 per 100,000. Although most patients claim a negative family history, we recently mapped this syndrome to chromosome 18p as an autosomal dominant trait in Family K from Northwest Germany. We now have investigated sporadic patients with IFD from the same geographic area both clinically and molecularly with chromosome 18p markers. The data indicate that most of these apparently sporadic patients have inherited the same mutation as Family K from a common ancestor and, in fact, owe their disease to autosomal dominant inheritance at low penetrance. The data also indicate that this dystonia mutation (DYT7) is the predominant cause of IFD, at least in this area of Northwest Germany, and that its location can be narrowed from a 30- to a 6-centimorgan region close to marker D18S1098.

Chromosomes, Human, Pair 18↗
PubMed1997

QALYs and mental health care.

Quality-adjusted life year measures (QALYs) have been fervently debated by researchers and decision makers concerned with resource allocation in the health care sector. They have been heralded as important aids to planning and priority setting, but also criticised on technical and ethical grounds. This paper examines these arguments with special reference to mental health care, the intention being to highlight the strengths and shortcomings of QALYs in this context. Issues pertinent to the application of QALYs in health care evaluation more generally are also reviewed. Whilst the rationale and underlying principles of the utility measurement approach are sound, the generic QALY as it is currently constructed represents an insensitive measure of the outcomes of mental health care. In the event of an increasingly QALY-driven priority-setting environment, however, abandonment of QALYs runs the risk of inappropriately marginalising people with mental illnesses in the resource allocation process. This opens up the possibility of developing a mental-health specific measure of utility that, in combination with cost data, would provide useful and appropriate summary information across treatments and programmes of mental health care.

Cost-Benefit Analysis↗
PubMed1997

The cost consequences of changing the hospital-community balance: the mental health residential care study.

BACKGROUND: Altering the balance of provision between hospital and community care is a key and often contentious component of mental health care policy in many countries. Implementation of this policy in the UK has been slowed by the apparent shortage of suitable community accommodation for people with long-term needs for care and support. Among the consequences could be the silting up of hospital beds by people who could be supported more appropriately elsewhere, in turn denying in-patient treatment to people with acute psychiatric problems and unnecessarily pushing up health service expenditure. METHODS: Using data collected in a survey of hospital and residential accommodation services and their residents in eight areas of England and Wales, the cost components of today's balance of care were explored. Comprehensive costs were calculated and their associations with resident characteristics examined using multiple regression analyses. RESULTS: On a like-with-like basis, the costs of hospital in-patient treatment for inappropriately placed patients greatly exceeded the costs of community-based care. CONCLUSION: Further reduction of hospital beds, however, is not the panacea for an appropriate balance of mental health care, given the unknown but potentially considerable extent of unmet demand, as well as the impact of previous in-patient bed reductions apparent in the services surveyed. Rather, service providers and purchasers should focus on developing community-based care (including increased provision of 24-hour nursed beds) by ensuring that resources released through earlier closure programmes have been redeployed for their intended use and by accessing additional pump-priming or bridging resources.

Chronic Disease↗