Recommendations for the nomenclature of cognitive change associated with anaesthesia and surgery-2018.

Cognitive change affecting patients after anaesthesia and surgery has been recognised for more than 100 yr. Research into cognitive change after anaesthesia and surgery accelerated in the 1980s when multiple studies utilised detailed neuropsychological testing for assessment of cognitive change after cardiac surgery. This body of work consistently documented decline in cognitive function in elderly patients after anaesthesia and surgery, and cognitive changes have been identified up to 7.5 yr afterwards. Importantly, other studies have identified that the incidence of cognitive change is similar after non-cardiac surgery. Other than the inclusion of non-surgical control groups to calculate postoperative cognitive dysfunction, research into these cognitive changes in the perioperative period has been undertaken in isolation from cognitive studies in the general population. The aim of this work is to develop similar terminology to that used in cognitive classifications of the general population for use in investigations of cognitive changes after anaesthesia and surgery. A multispecialty working group followed a modified Delphi procedure with no prespecified number of rounds comprised of three face-to-face meetings followed by online editing of draft versions. Two major classification guidelines [Diagnostic and Statistical Manual for Mental Disorders, fifth edition (DSM-5) and National Institute for Aging and the Alzheimer Association (NIA-AA)] are used outside of anaesthesia and surgery, and may be useful for inclusion of biomarkers in research. For clinical purposes, it is recommended to use the DSM-5 nomenclature. The working group recommends that 'perioperative neurocognitive disorders' be used as an overarching term for cognitive impairment identified in the preoperative or postoperative period. This includes cognitive decline diagnosed before operation (described as neurocognitive disorder); any form of acute event (postoperative delirium) and cognitive decline diagnosed up to 30 days after the procedure (delayed neurocognitive recovery) and up to 12 months (postoperative neurocognitive disorder).

A cost-effectiveness analysis of long-term intermittent catheterisation with hydrophilic and uncoated catheters.

STUDY DESIGN: Cost-effectiveness analysisObjective:To establish a model to investigate the cost effectiveness for people with spinal cord injury (SCI), from a lifetime perspective, for the usage of two different single-use catheter designs: hydrophilic-coated (HC) and uncoated (UC). The model includes the long-term sequelae of impaired renal function and urinary tract infection (UTI). SETTING: Analysis based on a UK perspective. METHODS: A probabilistic Markov decision model was constructed, to compare lifetime costs and quality-adjusted life years, taking renal and UTI health states into consideration, as well as other catheter-related events. UTI event rates for the primary data set were based on data from hospital settings to ensure controlled and accurate reporting. A sensitivity analysis was applied to evaluate best- and worst-case scenarios. RESULTS: The model predicts that a 36-year-old SCI patient with chronic urinary retention will live an additional 1.4 years if using HC catheters compared with UC catheters, at an incremental cost of £2100. Moreover, the lifetime number of UTI events will be reduced by 16%. All best- and worst-case estimates were within the UK threshold of being cost effective. CONCLUSION: The use of HC catheters for intermittent catheterisation in SCI patients is highly cost effective. The outcome is consistent irrespective of whether UTI data are collected in hospital or community settings.

The safety and effectiveness of different methods of earwax removal: a systematic review and economic evaluation.

BACKGROUND: Build-up of earwax is a common reason for attendance in primary care. Current practice for earwax removal generally involves the use of a softening agent, followed by irrigation of the ear if required. However, the safety and benefits of the different methods of removal are not known for certain. OBJECTIVES: To conduct evidence synthesis of the clinical effectiveness and cost-effectiveness of the interventions currently available for softening and/or removing earwax and any adverse events (AEs) associated with the interventions. DATA SOURCES: Eleven electronic resources were searched from inception to November 2008, including: The Cochrane Library; MEDLINE (OVID), PREMEDLINE In-Process & Other Non-Indexed Citations (OVID), EMBASE (OVID); and CINAHL. METHODS: Two reviewers screened titles and abstracts for eligibility. Inclusion criteria were applied to the full text or retrieved papers and data were extracted by two reviewers using data extraction forms developed a priori. Any differences were resolved by discussion or by a third reviewer. Study criteria included: interventions - all methods of earwax removal available and combinations of these methods; participants - adults/children presenting requiring earwax removal; outcomes - measures of hearing, adequacy of clearance of wax, quality of life, time to recurrence or further treatment, AEs and measures of cost-effectiveness; design - randomised controlled trials (RCTs) and controlled clinical trials (CCTs) for clinical effectiveness, cohort studies for AEs and cost-effectiveness, and costing studies for cost-effectiveness. For the economic evaluation, a deterministic decision tree model was developed to evaluate three options: (1) the use of softeners followed by irrigation in primary care; (2) softeners followed by self-irrigation; and (3) a 'no treatment' option. Outcomes were assessed in terms of benefits to patients and costs incurred, with costs presented by exploratory cost-utility analysis. RESULTS: Twenty-six clinical trials conducted in primary care (14 studies), secondary care (8 studies) or other care settings (4 studies), met the inclusion criteria for the review - 22 RCTs and 4 CCTs. The range of interventions included 16 different softeners, with or without irrigation, and in various different comparisons. Participants, outcomes, timing of intervention, follow-up and methodological quality varied between studies. On measures of wax clearance Cerumol, sodium bicarbonate, olive oil and water are all more effective than no treatment; triethanolamine polypeptide (TP) is better than olive oil; wet irrigation is better than dry irrigation; sodium bicarbonate drops followed by irrigation by nurse is more effective than sodium bicarbonate drops followed by self-irrigation; softening with TP and self-irrigation is more effective than self-irrigation only; and endoscopic de-waxing is better than microscopic de-waxing. AEs appeared to be minor and of limited extent. Resuts of the exploratory economic model found that softeners followed by self-irrigation were more likely to be cost-effective [24,433 pounds per quality-adjusted life-year (QALY)] than softeners followed by irrigation at primary care (32,130 pounds per QALY) when compared with no treatment. Comparison of the two active treatments showed that the additional gain associated with softeners followed by irrigation at primary care over softeners followed by self-irrigation was at a cost of 340,000 pounds per QALY. When compared over a lifetime horizon to the 'no treatment' option, the ICERs for softeners followed by self-irrigation and of softeners followed by irrigation at primary care were 24,450 pounds per QALY and 32,136 pounds per QALY, respectively. LIMITATIONS: The systematic review found limited good-quality evidence of the safety, benefits and costs of the different strategies, making it difficult to differentiate between the various methods for removing earwax and rendering the economic evaluation as speculative. CONCLUSIONS: Although softeners are effective, which specific softeners are most effective remains uncertain. Evidence on the effectiveness of methods of irrigation or mechanical removal was equivocal. Further research is required to improve the evidence base, such as a RCT incorporating an economic evaluation to assess the different ways of providing the service, the effectiveness of the different methods of removal and the acceptability of the different approaches to patients and practitioners.

The clinical and cost-effectiveness of left ventricular assist devices for end-stage heart failure: a systematic review and economic evaluation.

OBJECTIVES: To assess the clinical and cost-effectiveness of left ventricular assist devices (LVADs) as a bridge to heart transplantation (BTT), as a bridge to myocardial recovery (BTR) or as a long-term chronic support (LTCS) for people with end-stage heart failure (ESHF). DATA SOURCES: For the systematic review, electronic databases and bibliographies of related publications plus experts and manufacturers. For the economic evaluations, data originated from the systematic review of clinical and cost-effectiveness, UK hospitals, device manufacturers and expert opinion. REVIEW METHODS: For the systematic review, studies were selected and assessed against a set of rigorous criteria; data were then synthesised using a narrative approach through subgroup analysis based on the indication for treatment, type of LVAD and quality of studies. The economic evaluation developed two models to evaluate the use of LVADs, first as a BTT and second as LTCS for patients suffering from ESHF. RESULTS: Sixteen studies assessed the clinical effectiveness of LVADs as a BTT. Despite the poor methodological quality of the evidence, LVADs appeared beneficial compared to other treatment options (i.e. inotropic agents or usual care) or to no care (i.e. the natural history of ESHF) improving the survival of people with ESHF during the period of support and following heart transplantation. Patients supported by an LVAD appeared to have an improved functional status compared with those on usual care and experienced an improvement in their quality of life from before device implantation to the period during support. Serious adverse events are a risk for patients with an LVAD. With a scarcity of evidence directly comparing different devices, it is difficult to identify specific devices as the most clinically effective. The HeartMate LVAD is the only device that has evidence comparing it with the different alternatives, appearing to be more clinically effective than inotropic agents and usual care and as clinically effective as the Novacor device. Second generation devices, such as Jarvik 2000 and MicroMed Debakey LVADs, are early in their development but show considerable promise that should be assessed through long-term studies. Evidence of the clinical effectiveness of LVADs as a BTR was limited to seven non-comparative observational studies that appeared to show that the LVADs were beneficial in providing support until myocardial recovery. It was not possible to assess whether the LVADs are more effective than other alternatives or specific devices. No evidence was found on the quality of life or functional status of patients and limited information on adverse events was reported. Six studies assessed the clinical effectiveness of LVADs as an LTCS and from these it was evident that LVADs provided benefits in terms of improved survival, functional status and quality of life. Nineteen studies assessed the costs and cost-effectiveness of LVADS for people with ESHF, with the majority being simple costing studies and very few studies of the cost-effectiveness of LVADs. With no relevant cost-effectiveness studies available, an economic evaluation for BTT and LTCS was developed. The economic evaluation has shown that neither LVAD indication considered, that is, BTT and LTCS, is a cost-effective use. For the HeartMate LVAD used as a BTT the cost per QALY was pound 65,242. In the less restrictive indication, LTCS, where LVADs are not just given to patients awaiting transplantation, the analysis has shown that LTCS is not cost-effective. The baseline cost per QALY of the first-generation HeartMate LVAD was pound 170,616. One- and multi-way sensitivity analysis had limited effect on the cost per QALY. A hypothetical scenario based on the cost of a second-generation MicroMed DeBakey device illustrated that a 60% improvement in survival over first-generation devices was necessary before the incremental cost-effectiveness approached pound 40,000 per QALY. CONCLUSIONS: Although the review showed that LVADs are clinically effective as a BTT with ESHF, the economic evaluation indicated that they are not cost-effective. With the limited and declining availability of donor hearts for transplantation, it appears that the future of the technology is in its use as an LTCS. Further research is needed to examine the clinical effectiveness of LVADs for people with ESHF, assessing patient survival, functional ability, quality of life and adverse events. Evaluations of the clinical effectiveness of LVADs should include economic evaluations, as well as data on quality of life, utilities, resources and costs. A systematic review of the epidemiology of ESHF should be undertaken to assess its potential impact.

Clinical and cost effectiveness of paclitaxel, docetaxel, gemcitabine, and vinorelbine in non-small cell lung cancer: a systematic review.

BACKGROUND: Lung cancer remains a devastating disease with few effective treatment options. Recent developments in chemotherapy have led to cautious optimism. This paper reviews the evidence on the clinical and cost effectiveness of four of the new generation drugs for patients with lung cancer. METHODS: A systematic review of randomised controlled trials (RCTs) identified from 11 electronic databases (including Medline, Cochrane library and Embase), reference lists and contact with experts and industry was performed to assess clinical effectiveness of paclitaxel, docetaxel, gemcitabine and vinorelbine. Clinical effectiveness was assessed using the outcomes of patient survival, quality of life, and adverse effects. Cost effectiveness was assessed by development of a costing model and presented as incremental cost per life year saved (LYS) compared with best supportive care (BSC). RESULTS: Of the 33 RCTs included, five were judged to be of good quality, 10 of adequate quality, and 18 of poor quality. Gemcitabine, paclitaxel, and vinorelbine as first line treatment and docetaxel as second line treatment appear to be more beneficial for non-small cell lung cancer than BSC and older chemotherapy agents, increasing patient survival by 2-4 months against BSC and some comparator regimes. These gains in survival do not appear to be at the expense of quality of life. Survival gains were delivered at reasonable levels of incremental cost effectiveness for vinorelbine, vinorelbine with cisplatin, gemcitabine, gemcitabine with cisplatin, and paclitaxel with cisplatin regimens compared with BSC. CONCLUSION: Although the clinical benefits of the new drugs appear relatively small, their benefit to patients with lung cancer appears to be worthwhile and cost effective.

Eliciting public preferences for healthcare: a systematic review of techniques.

BACKGROUND: Limited resources coupled with unlimited demand for healthcare mean that decisions have to be made regarding the allocation of scarce resources across competing interventions. Policy documents have advocated the importance of public views as one such criterion. In principle, the elicitation of public values represents a big step forward. However, for the exercise to be worthwhile, useful information must be obtained that is scientifically defensible, whilst decision-makers must be able and willing to use it. AIMS AND OBJECTIVES: The aim was to identify techniques that could be reasonably used to elicit public views on the provision of healthcare. Hence, the objectives were: (1) to identify research methods with the potential to take account of public views on the delivery of healthcare; (2) to identify criteria for assessing these methods; (3) to assess the methods identified according to the predefined criteria; (4) to assess the importance of public views vis-à-vis other criteria for setting priorities, as judged by a sample of decision-makers; (5) to make recommendations regarding the use of methods and future research. METHODS: A systematic literature review was carried out to identify methods for eliciting public views. Criteria currently used to evaluate such methods were identified. The methods identified were then evaluated according to predefined criteria. A questionnaire-based survey assessed the relative importance of public views vis-à-vis five other criteria for setting priorities: potential health gain; evidence of clinical effectiveness; budgetary impact; equity of access and health status inequalities; and quality of service. Two techniques were used: choice-based conjoint analysis and allocation of points technique. The questionnaire was sent to 143 participants. A subsample was followed up with a telephone interview. RESULTS: The methods identified were classified as quantitative or qualitative. RESULTS - QUANTITATIVE TECHNIQUES: Quantitative techniques, classified as ranking, rating or choice-based approaches, were evaluated according to eight criteria: validity; reproducibility; internal consistency; acceptability to respondents; cost (financial and administrative); theoretical basis; whether the technique offered a constrained choice; and whether the technique provided a strength of preference measure. Regarding ranking exercises, simple ranking exercises have proved popular, but their results are of limited use. The qualitative discriminant process has not been used to date in healthcare, but may be useful. Conjoint analysis ranking exercises did well against the above criteria. A number of rating scales were identified. The visual analogue scale has proved popular within the quality-adjusted life-year paradigm, but lacks constrained choice and may not measure strength of preference. However, conjoint analysis rating scales performed well. Methods identified for eliciting attitudes include Likert scales, the semantic differential technique, and the Guttman scale. These methods provide useful information, but do not consider strength of preference or the importance of different components within a total score. Satisfaction surveys have been frequently used to elicit public opinion. Researchers should ensure that they construct sensitive techniques, despite their limited use, or else use generic techniques where validity has already been established. Service quality (SERVQUAL) appears to be a potentially useful technique and its application should be researched. Three choice-based techniques with a limited application in healthcare are measure of value, the analytical hierarchical process and the allocation of points technique, while those more widely used, and which did well against the predefined criteria, include standard gamble, time trade-off, discrete choice conjoint analysis and willingness to pay. Little methodological work is currently available on the person trade-off. RESULTS - QUALITATIVE TECHNIQUES: Qualitative techniques were classified as either individual or group-based approaches. Individual approaches included one-to-one interviews, dyadic interviews, case study analyses, the Delphi technique and complaints procedures. Group-based methods included focus groups, concept mapping, citizens' juries, consensus panels, public meetings and nominal group techniques. Six assessment criteria were identified: validity; reliability; generalisability; objectivity; acceptability to respondents; and cost. Whilst all the methods have distinct strengths and weaknesses, there is a lot of ambiguity in the literature. Whether to use individual or group methods depends on the specific topic being discussed and the people being asked, but for both it is crucial that the interviewer/moderator remains as objective as possible. The most popular and widely used such methods were one-to-one interviews and focus groups. (ABSTRACT TRUNCATED)

A rapid and systematic review of the clinical effectiveness and cost-effectiveness of paclitaxel, docetaxel, gemcitabine and vinorelbine in non-small-cell lung cancer.

BACKGROUND: The incidence of lung cancer is declining following a drop in smoking rates, but it is still the leading cause of death from cancer in England and Wales, with about 30,000 deaths a year. Survival rates for lung cancer are poor everywhere, but they appear to be better in the rest of the European Community and the USA than in the UK. Only about 5 per cent of people with lung cancer survive for 5 years, and nearly all of these are cured by surgery after fortuitously early diagnosis. At present, only a small proportion of patients (probably about 5 per cent) with non-small-cell lung cancer are being given chemotherapy. Some centres treat a greater proportion. OBJECTIVES: This review examines the clinical effectiveness and cost-effectiveness of four of the newer drugs - vinorelbine, gemcitabine, paclitaxel and docetaxel - used for treating the most common type of lung cancer (non-small-cell lung cancer). The first three drugs are used for first-line treatment, but at present docetaxel is used only after first-line chemotherapy has failed. METHODS: This report was based on a systematic literature review and economic modelling, supplemented by cost data. RESULTS - NUMBER AND QUALITY OF STUDIES: A reasonable number of randomised trials were found - three for docetaxel, six for gemcitabine, five for paclitaxel and 13 for vinorelbine. The quality of the trials was variable but good overall. There was a wide range of comparators. Some trials compared chemotherapy with best supportive care (BSC), which involves care that aims to control symptoms, with palliative radiotherapy if needed, but not to prolong life. Others compared the newer drugs against previous drugs or combinations. RESULTS - SUMMARY OF BENEFITS: The gains in duration of survival with the new drugs are modest - a few months - but worthwhile in a condition for which the untreated survival is only about 5 months. There are also gains in quality of life compared with BSC, because on balance the side-effects of some forms of chemotherapy have less effect on quality of life than the effects of uncontrolled spread of cancer. RESULTS - COSTS: The total cost to the NHS of using these new drugs in England and Wales might be about GBP 10 million per annum, but is subject to a number of factors. There would be non-financial constraints on any increase in chemotherapy for the next few years, such as staffing; the number of patients choosing to have the newer forms of chemotherapy is not yet known; and the costs of the drugs may fall, for example, as generic forms appear. RESULTS - COST PER LIFE-YEAR GAINED: The available data did not provide an entirely satisfactory basis for cost-effectiveness calculations. The main problem was the lack of direct comparisons of the new drugs. In order to strengthen the analysis, three different modelling approaches were used: pairwise comparisons using trial data; cost-minimisation analysis, as if all the new regimens were of equal efficacy; and cost-effectiveness analysis pooling the results of several trials with different comparators, giving indirect comparisons of the new drugs by using BSC as the common comparator. A number of different scenarios were explored through extensive sensitivity analysis in each model. Outcomes were expressed in incremental cost per life-year saved or incremental cost, versus BSC. There was insufficient evidence from which to derive cost per quality-adjusted life-year. In first-line treatment, vinorelbine, gemcitabine, and the lower-dose paclitaxel plus cisplatin combinations generally performed well against BSC under a range of different scenarios and especially when given as a maximum of 3 cycles. Incremental cost per life-year gained (LYG) versus BSC varied depending on scenario, but baseline figures based on trial data and protocols were: single-agent vinorelbine, pound 2194 per LYG; vinorelbine plus cisplatin, pound 5206; single-agent gemcitabine, pound 5690; gemcitabine plus cisplatin, pound 10,041; and paclitaxel plus cisplatin, pound 8537. In second-line chemotherapy, docetaxel gave a cost per LYG of pound 17,546, again well within the range usually accepted as cost-effective. However, in routine care, the impact of therapy would be regularly reviewed, and continuation would depend on response, side-effects, patient choice and clinical judgement. Chemotherapy would be stopped in non-responders, making chemotherapy more cost-effective. A 'real-life' scenario in which 60 per cent of patients receive only 1 or 2 cycles of chemotherapy gives much lower costs per LYG, with single-agent gemcitabine, single-agent vinorelbine, and paclitaxel plus platinum appearing to be cost-saving compared with BSC; the incremental cost of gemcitabine plus cisplatin would be pound 2478 per LYG, and of vinorelbine plus cisplatin, pound 2808. At the very least, gains in duration of survival were achieved without diminution of quality of life (at best, they improved quality) and with relatively low incremental cost. Comparisons among the individual drugs should be viewed with caution because they have had to be based on indirect comparisons. RESULTS - LIMITATIONS OF THE ANALYSIS: Each of the three models had limitations. The cost-effectiveness estimates from the pairwise comparisons were based on single studies. The cost-minimisation analysis assumed that the regimens have equal efficacy in practice. The cost-effectiveness analysis had to be based on pooling data from individual trials. The costs of BSC, inpatient stay and outpatient visits were from Scottish data. Median rather than mean data on duration of survival have been used in the analysis, because most of the trials reported only median data. Median survival and number of drug cycles were calculated by averaging across a number of studies, rather than being reliant on one particular study. The costs of the less expensive antiemetics cited in the trials were omitted. The use of more modern and costly antiemetics would have a modest detrimental effect on cost-effectiveness. In the absence of published data, an estimate was made of the cost of side-effects of chemotherapy, in particular hospital admissions, and applied to all the new regimens. In practice, admissions related to side-effects and their respective costs are likely to vary by regimen. CONCLUSIONS: The new drugs for non-small-cell lung cancer extend life by only a few months compared with BSC, but appear to do so without net loss in quality of life and at a cost per LYG that is much lower than for many other NHS activities. Depending on assumptions used, these new drugs range from being cost-effective, as conventionally accepted, to being cost-saving. CONCLUSIONS - IMPLICATIONS OF THE NEWER DRUGS: One of the present constraints on chemotherapy is availability of inpatient beds. The advent of newer and gentler forms of chemotherapy given on an outpatient basis would not only overcome this, but it would allow more patients to be treated. This might apply particularly to older patients. The treatment of more patients would increase workload for oncologists, cancer nurses and pharmacists. The Government has already announced increased expenditure on staff for cancer care. The previously pessimistic attitudes to chemotherapy in non-small-cell lung cancer are changing in the wake of the newer agents, and this shift is likely to increase referral. CONCLUSIONS - NEED FOR FURTHER RESEARCH: Recent advances in chemotherapy are welcome, but their effects remain small for patients with non-small-cell lung cancer. Much more research is needed into better drugs, better combinations, new ways of assessing the likelihood of response and especially direct comparisons between the new regimens. This research would be aided by having a greater proportion of patients involved in trials, but there will be infrastructure implications of increased participation.

The use of CT scanning in dementia. A systematic review.

While reversible cases of dementia are rare once detected, the patient may benefit from treatment. This paper examines the cost-effectiveness of computerized tomography (CT) scanning as a screening test for potentially reversible dementia. A systematic review was carried out to identify the proportion of patients with dementia above and below the age of 65 years with a theoretically treatable condition and the proportion of these patients who would benefit from neurosurgery. Information was combined with epidemiological and financial data relating to Scotland to model the costs and benefits of implementing a national screening program. Subdural hematoma, normal pressure hydrocephalus, and brain tumours are rare conditions treatable by neurosurgery. A scanning and treatment program for Scotland would cost 4.6 million Pounds per annum. Of 531 reversible cases detected, 136 would benefit from neurosurgery, 369 would not benefit, and 26 would die as a result of surgery. Treating normal pressure hydrocephalus reduces overall quality-adjusted survival. The most cost effective screening strategy is to scan all patients but treat only subdural hematomas, gaining 178 quality-adjusted life-years (QALYs) at a cost of 14,171 Pounds per QALY for patients aged 65 at the time of the scan. The corresponding figures for patients above and below 65 years are 9,000 Pounds and 23,000 Pounds, respectively. CT scanning appears cost-effective in dementia patients under 65 years. It should be undertaken selectively in more elderly patients. Surgical treatment of normal pressure hydrocephalus may reduce quality adjusted survival and should only be undertaken within clinical trials.

Managerial perceptions of the incentives inherent in National Health Service capital charging.

Capital charging was introduced into the National Health Service (NHS) in 1991 in order to stop capital being treated as a 'free' good and to encourage managers to use their assets more efficiently. This article seeks to examine the extent to which managerial thinking has been influenced. It uses as evidence interviews with NHS managers conducted in Scotland in 1994. The following uses of capital charges data are explored: capital programme; disposal programme; maintenance programme; contract pricing; and budgetary devolution. New capital programmes required more justification and capital charges were seen as relevant to estate rationalization. Less effect was found with regard to the maintenance programme, though this may have been due to a downgrading of the estates function in most Trusts. Although the capital charge costs included in contract prices affect the competitive position of providers, there was criticism of the lack of development of the purchasing function. Budgetary devolution was proceeding relatively slowly but, among those Trusts which had devolved capital charges, evidence was found that some clinicians were becoming aware of the full costs of equipment use. This article concludes, with cautious optimism, that capital charges are beginning to influence decisions and that, despite some incentives being dysfunctional, they will lead to a better managed NHS.

Computer systems for dental practice management: a new generation of independent dental software.

A new generation of computer programs for dental patient management eliminates total dependence on the vendor for programming support. The software design enables information collected with the dental system to be transferred to popular off-the-shelf programs designed for business. A simplified example is used to illustrate the practitioners the advantages of this type of data structure management. Programs designed on this basis offer optimum performance and expandability for both present and future needs.

The rational zero point for an illness index with ratio properties.

To be of greatest use for the measurement of significant variations in treatment outcomes, a health status index should have ratio properties. Previous attempts to construct such a scale using the magnitude estimation technique have failed, principally because of an inappropriate choice for the zero point. By rejecting death as the logical zero point for a scale of social preference and choosing instead the absence of that being measured (dysfunction and discomfort), the authors attained reliable values from patients, for an illness index, using magnitude estimation. This type of scale allows comparative judgments between treatment methods to be made with greater validity. It should aid in the wise allocation of health care resources.