Problems in conducting economic evaluations alongside clinical trials. Lessons from a study of case management for people with mental disorders

BACKGROUND

Case management has become the statutory basis of community care in the UK for people with long-term mental disorders, although a randomised controlled trial found no important improvements over standard care. Here we compare the costs and cost consequences of this intervention with standard care.

METHOD

Resource-use data were collected over a six-month baseline period and for 14 months after randomisation on all patients in the trial.

RESULTS

At 14 months the ratio of control group to treatment group weekly costs was 1.09 (95% CI 0.86-1.38) for total costs; 1.12 (0.76-1.65) for state benefits, and 1.21 (0.61-2.42) for health care costs. Costs were thus lower in the treatment group, but these differences were not significant.

CONCLUSIONS

Retrospective power calculations indicated that the trial could have detected differences of 30% in total cost, but would have required 700 patients per arm to detect a 20% difference in health care costs. Hence this study, which had adequate power to detect clinically meaningful differences, was found to be far too small to detect large differences in costs. Funding agencies increasingly request that clinical trials include economic alongside clinical end-points: these findings may have important lessons for that policy.

A new method of intralesional bleomycin therapy in the treatment of recalcitrant warts

We have used a new technique of bleomycin injection to treat intractable palmar, plantar and periungual warts. Following local anaesthesia with topical EMLA (lignocaine and prilocaine) cream, 1 mg/ml bleomycin solution was dropped on to the wart and 'pricked' into the wart using a Monolet needle. We achieved 92% success rate which compares well with other authors whose success rates with intralesional bleomycin vary between 33 and 92%. We conclude that this technique of intralesional bleomycin therapy is an effective, safe and generally well tolerated treatment for recalcitrant warts.

Insulin like growth factor-binding protein-1 as a marker for hyperinsulinemia in obese menopausal women

Hyperinsulinemia, a manifestation of insulin resistance, precursor of non-insulin dependent diabetes mellitus (NIDDM) and the hallmark of Syndrome X was assessed in 27 obese post-menopausal women. Insulin-like growth factor binding protein-1 (IGFBP-1), which had been shown previously to correlate inversely with insulin in animal and human studies, was evaluated as a diagnostic marker for abnormal glucose stimulated area under the curve (AUC) insulin (defined a priori as > or = 100 microU/ml). We performed analysis of variance and logistic regression to assess IGFBP-1 and other study covariates, including body mass index, blood pressure, lipids and measures of glucose and insulin in hyperinsulinemic vs. normal women and evaluated performance characteristics (sensitivity, specificity, positive and negative predictive values and accuracy rates). The mean IGFBP-1 was 6.1 ng/ml (95% confidence interval (CI) 3.1 to 8.9) for the hyper-insulinemic women compared to 33.5 ng/ml (CI 15.8 to 51.2) for normal women (P = .0027). At a cutoff point of 15ng/ml, which was selected to correspond to the lower 95% confidence limit for the normal study population, IGFBP-1 was abnormal in all 13 women with hyperinsulinemia and 4 women with normal insulin levels (sensitivity 100%, specificity 69%; positive predictive value 76%, negative predictive value 100%, diagnostic accuracy rate 85%). Logistic regression models indicated that, of all study covariates, IGFBP-1 was the best predictor variable for AUC-insulin as a binary dependent variable. These results suggest that IGFBP-1 may be a simple serum marker for hyperinsulinemia in a subpopulation of obese menopausal women.

Oligomerization activates c-Raf-1 through a Ras-dependent mechanism

The c-Raf-1 proto-oncoprotein is a Ras-GTP-regulated protein kinase that associates in situ with 14-3-3 proteins, which are naturally dimeric. In COS cells, recombinant Raf is found in oligomeric assemblies. To examine whether induced oligomerization can alter Raf kinase activity, sequences encoding the FK506-binding protein FKBP12 were fused to the amino terminus of c-Raf-1, introducing a binding site for FK506. Oligomerization of recombinant FKBP-Raf in situ, induced by the addition of the dimeric FK506 derivative FK1012A, activated Raf kinase activity at least half as well as epidermal growth factor (EGF). As with EGF, activation of FKBP-Raf by FK1012A is entirely Ras-GTP dependent. Thus oligomerization of Raf per se promotes Raf activation through a Ras-dependent mechanism.

N-terminal sequences contained in the Src homology 2 and 3 domains of p120 GTPase-activating protein are required for full catalytic activity toward Ras

The p120 GTPase-activating protein (GAP) is a negative regulator of Ras, which has a central role in signal transduction pathways that control cell proliferation. p120 GAP accelerates the conversion of activated Ras-GTP to its inactive form, Ras-GDP, thereby inhibiting mitogenic signaling. To examine potential contributions of p120 N-terminal sequences to regulation of its C-terminal catalytic domain, we constructed deletion mutants lacking defined regions, including the variable hydrophobic region as well as the Src homology 2 (SH2) and 3 (SH3) domains. These mutant proteins were expressed in infected Sf9 insect cells from recombinant baculoviruses and assayed in vitro for their ability to stimulate the intrinsic GTPase activity of purified Ras. While deletion of the variable hydrophobic region had no effect on p120 GAP activity, deletion of the entire SH2/SH3/SH2 region severely impaired catalytic activity toward Ras. Deletion of individual SH2 and SH3 domains within this region partially inhibited p120 GAP activity. Moreover, p120 N-terminal sequences enhanced the Ras GTPase-stimulating activity of the neurofibromin GAP-related domain. These results demonstrate that sequences in the SH2/SH3/SH2 region of p120 GAP are required for full catalytic activity toward Ras. Together with earlier findings that the p120 GAP SH2 domains mediate interactions with several GAP-associated proteins, our results suggest multiple roles for the N-terminal sequences in regulating p120 GAP catalytic activity and mitogenic signaling pathways. In addition, our results raise the possibility that SH2 domain point mutations in p120 GAP detected in some basal cell carcinomas reduce catalytic activity toward Ras and thereby contribute to oncogenesis.

Interactions between Ras and Raf: key regulatory proteins in cellular transformation

Ras proteins function during cell growth and development as essential, plasma membrane-bound signaling proteins. Current evidence suggests that Ras is part of a signal transduction chain extending from extracellular signals to transcriptional regulation in the nucleus. Growth factor and cytokine activation of many tyrosine kinase and kinase-linked receptors recruits many proteins to the plasma membrane including Ras-specific guanine nucleotide releasing proteins (GNRP). Under the influence of a GNRP, Ras proteins bind GTP, resulting in activation of the Ras signal. The GTP-bound form of Ras is capable of interacting directly with RasGAP, neurofibromin, and the Raf kinases. Although believed to be endowed with some signaling capacity, RasGAP and neurofibromin act primarily to negatively regulate Ras. Based upon genetic and biochemical studies in a variety of diverse organisms, the Raf kinases are considered the primary targets of Ras signaling. Activation of the Raf kinases is the first step in a cascade of multiple protein kinases, including Mek, Erk1, and Erk2. We are attempting to understand structurally how activated Ras proteins interact specifically with Raf kinases to induce the downstream signals necessary for cell division. Using mutagenesis, peptide epitope scanning, and in vitro reconstitution of protein interactions, we have identified specific sites of association between the Ras-GTP and c-Raf-1 proteins. The interaction between these contact points is essential for the plasma membrane localization of Raf, which ultimately leads to kinase activation. The formation of this protein complex is negatively regulated by protein kinase A (PKA) through phosphorylation of the c-Raf-1 N-terminus. Phosphorylation of c-Raf-1 serine 43 is believed to cause an N-terminal cap structure to cover the Ras docking site.

The Cardinal Needs Schedule--a modified version of the MRC Needs for Care Assessment Schedule

This paper describes a modified version of the MRC Needs for Care Schedule (the Cardinal Needs Schedule), for measuring needs for psychiatric and social care amongst patients with severe psychiatric disorders. The modified schedule has three new features: (i) it is quick and easy to use; (ii) it takes systematic account of the views of patients and their carers; (iii) it defines and identifies need in a way that is concise and easy to interpret. The paper describes why the three new features were considered necessary, and then gives an overview of the structure of the Cardinal Needs Schedule, together with a description of how the three new features were developed. During a study of social services care management the practicality of the modified schedule was investigated and further data were obtained on the reliability and validity of the standardized approach to measuring need, in domains not previously investigated. Because of its speed and simplicity, the Cardinal Needs Schedule offers a new choice to researchers who wish to use a standardized and practical assessment of need in evaluative studies of community care. Examples of the usage of the modified schedule are given in an Appendix.

Identification of the sites of interaction between c-Raf-1 and Ras-GTP

Specific sites of protein-protein interaction were identified in the 51-149 region of c-Raf-1 using contact epitope scanning and site-directed mutagenesis. Nineteen overlapping peptides based upon the primary sequence of the Ras binding domain of c-Raf-1 were tested for the ability to competitively inhibit complex formation between Ras-GTP and the c-Raf-1 N-terminus. A peptide containing c-Raf-1 residues 91-105 as well as five overlapping peptides covering a region extending from residues 118 to 143 interfered with Ras association, defining these sites as potential contact surfaces with Ras. Alanine scanning mutagenesis was used as a second probe for sites of Ras interaction with the c-Raf-1 N-terminus. Raf residues 64-67 and 80-103 were demonstrated as important for association with Ras-GTP with residues 66, 67, 84, 87, 89 and 91 identified as the most critical individual points of contact with the Ras protein. Alanine substitution of residues between 118-143 suggested only one potentially weak site of interaction defined by residues 120-125. The combined results of both peptide and mutagenic analyses suggest that the primary site of c-Raf-1 interaction with Ras maps to Raf residues 80-103, with secondary interactions occurring with residues 66 and 67 and possibly 120-125. Contact epitope scanning of the Ras effector region found maximum inhibition of Ras/Raf association with a peptide corresponding to Ras amino acids 37-51. A model is proposed for the GTP-dependent association of Ras and Raf.

Social services case-management for long-term mental disorders: a randomised controlled trial

Case management arose in the USA as a solution to the difficulties of providing community care to people with severe mental disorders. The basic principle of the approach is that a case manager takes responsibility for a client; arranges an assessment of need, a comprehensive service plan, delivery of suitable services, and monitoring and assessment of services delivered. The case-management approach has been widely accepted, to the extent that recent legislation has made case-management the cornerstone of community care in the UK. We did a randomised controlled trial to evaluate a social services case-management team for people with long-term mental disorders. Subjects were referred from hostels for the homeless, night shelters, a general-practitioner clinic for the homeless, the Oxford City Council homelessness unit, and local voluntary-sector group homes. Of 103 subjects referred, 80 consented to be randomised to treatment or control groups. At 14-month follow-up, as assessed by standardised interviews, there were no significant differences between groups in number of needs, quality of life, employment status, quality of accommodation, social behaviour, or severity of psychiatric symptoms. In the case-management group there was a significant reduction in deviant behaviour on a standardised behaviour rating scale (REHAB) (mean = 0.79; 95% CI 0.26-1.32). It is unfortunate, in view of the limited effectiveness we have shown, that social services case-management was not evaluated in randomised controlled trials before its implementation in the UK.

Why do so few patients appeal against detention under Section 2 of the Mental Health Act?

OBJECTIVE

To determine why most patients do not exercise their right of appeal against detention under section 2 of the Mental Health Act 1983.

DESIGN

Part one--retrospective analysis of the clinical notes of patients detained under section 2 of the Mental Health Act. Part two-interviews with patients on the penultimate day before the deadline for lodging an appeal.

SETTING

In part one, five districts in the Oxfordshire Regional Health Authority. In part two, six hospitals from three districts in the region.

SUBJECTS

In part one all patients detained under section 2 in the five districts in 1993 (n = 418). In part two interviews with 40 patients detained under section 2 in the six hospitals.

RESULTS

Patients were more likely to appeal if they were educated to A level standard (odds = 2.26; P = 0.0014) or had had a previous admission (2.19, P = 0.0029). Patients with a diagnosis of depression (0.31; P = 0.0.15) or dementia (0.0003, P = 0.0001) were less likely to appeal. Compared with those who appealed (n = 12) those who did not (n = 28) showed less understanding of their rights (P = 0.034) and poorer comprehension of sentences from the booklet describing patients' rights (P = 0.057). The main reasons given for not appealing were not being aware of the appeals process and being deterred by having to appeal in writing. After they received a full explanation of their rights 12 of those who did not appeal said that they wished to appeal and four did so within the time remaining before the deadline. Of 40 patients, 39 said there should be an automatic right of appeal.

CONCLUSIONS

The appeals procedure against detention under section 2 of the Mental Health Act is not a satisfactory way of protecting the civil liberties of patients. If patients were fully informed of their rights they would probably be much more likely to appeal.

Evidence for a high molecular weight pre-robustoxin molecule in the venom of the male Sydney funnel-web spider (Atrax robustus)

Robustoxin is the lethal polypeptide toxin in Atrax robustus venom. A monoclonal antibody was produced using synthetic, unfolded robustoxin conjugated to keyhole limpet haemocyanin as the immunogen. This monoclonal antibody did not protect newborn mice against challenge with the crude venom of the male Sydney funnel-web spider, but did slightly prolong their survival time. Western blotted crude venom of the male Sydney funnel-web spider showed two monoclonal antibody binding bands. One band at low M(r) corresponded to robustoxin (M(r) 4854), while the other higher M(r) band (approximately 37,000) may be due to a pre-robustoxin molecule.

Speech-language patterns in a child with moya moya disease

Moya Moya disease is a cerebrovascular condition associated with occlusion of the terminal portion of the internal carotid artery along with the appearance of an abnormal net-like system of collateral blood vessels. This paper presents a description beginning in 1973 over a 6-yr. period of the speech-language performance of a Caucasian female diagnosed with the disease.

Effect of endotoxin and cytokines on lipoprotein lipase activity in mice

Endotoxin (lipopolysaccharide [LPS]) stimulates the production of cytokines, which mediate many of the metabolic effects associated with infection. In LPS-sensitive C57B1/6 mice, LPS doses as low as 0.01 micrograms per mouse decreased adipose tissue lipoprotein lipase (LPL) activity by greater than 50%. In LPS-resistant C3H/HeJ mice, which do not produce cytokines in response to LPS, doses of LPS as high as 10 micrograms per mouse did not affect LPL activity in adipose tissue. In muscle of C57Bl/6 mice, LPL activity was decreased by 27% after 10 micrograms of LPS, whereas in C3H/HeJ mice there was no effect. These results indicate that the LPS-induced decrease in both adipose and muscle LPL activity is mediated by cytokines. Tumor necrosis factor (TNF), interleukin (IL)-1, leukemia-inhibiting factor (LIF), interferon alfa, and interferon gamma all decreased adipose tissue LPL activity in intact mice. In skeletal and cardiac muscle, only IL-1 and interferon gamma decreased LPL activity, whereas TNF, LIF, and interferon alfa had no effect. Inhibition of TNF activity blocked the increase in serum triglycerides that is characteristically observed after LPS but did not affect the ability of LPS to decrease adipose tissue LPL activity. Inhibition of IL-1 activity with IL-1 receptor antagonist partially inhibited the increase in serum triglycerides; however, the ability of LPS to decrease LPL activity in either adipose or muscle tissue was not affected. These data indicate that although TNF and IL-1 play a role in mediating the increase in serum triglyceride levels, these cytokines do not play a crucial role in the inhibition of either adipose or muscle LPL activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural analysis of the Ras GTPase activating protein catalytic domain by semirandom mutagenesis: implications for a mechanism of interaction with Ras-GTP

The bovine complementary DNA encoding the catalytic domain of Ras GTPase activating protein was mutagenized semirandomly using a variation of the polymerase chain reaction. Sixty-four mutated codons were identified with seventeen of the mutations deleterious to Ras GTPase activating function. All of the inactivating single mutations affected the structure of the catalytic fragment as assessed by large decreases in soluble protein when expressed in Escherichia coli. Upon examination of the Ras binding properties of 10 of the mutants, only 1 was measurably impaired for Ras binding and 4 appeared to have increased affinity for Ras. These results demonstrate that Ras binding and GTPase activation are two distinct properties of GTPase activating protein. Additionally, the catalytic mechanism of GTPase activating protein is much more sensitive to structural perturbation than is Ras binding.

Dementia in acute units: the issues

To coincide with World Alzheimer's Day, Nursing Standard this week launches a major new series which looks in detail at one of the most pressing nursing problems of the age--coping with the behaviours of people with dementia who are admitted to acute care units. The series, which consists of seven articles, presented at monthly intervals, takes a very practical look at how nurses in such units can cope with patients who display behaviours such as wandering, aggression, sexual disinhibition and agitation--behaviours which nurses have difficulty understanding and managing.(ABSTRACT TRUNCATED AT 250 WORDS)