PATIENT AND PUBLIC INVOLVEMENT IN EARLY AWARENESS AND ALERT ACTIVITIES: AN EXAMPLE FROM THE UNITED KINGDOM.

OBJECTIVES: The aim of this study is to report on the experiences, benefits, and challenges of patient and public involvement and engagement (PPIE) from a publicly funded early awareness and alert (EAA) system in the United Kingdom. METHODS: Using email, telephone, a Web site portal, Twitter and focus groups, patients and the public were involved and engaged in the recognized stages of an EAA system: identification, filtration, prioritization, early assessment, and dissemination. RESULTS: Approaches for PPIE were successfully integrated into all aspects of the National Institute for Health Research Horizon Scanning Research and Intelligence Centre's EAA system. Input into identification activities was not as beneficial as involvement in prioritization and early assessment. Patients gave useful insight into the Centre's Web site and engaging patients using Twitter has enabled the Centre to disseminate outputs to a wider audience. CONCLUSIONS: EAA systems should consider involving and engaging with patients and the public in identification, prioritization, and assessment of emerging health technologies where practicable. Further research is required to examine the value and impact of PPIE in EAA activities and in the early development of health technologies.

Past speculations of future health technologies: a description of technologies predicted in 15 forecasting studies published between 1986 and 2010.

OBJECTIVE: To describe and classify health technologies predicted in forecasting studies. DESIGN AND METHODS: A portrait describing health technologies predicted in 15 forecasting studies published between 1986 and 2010 that were identified in a previous systematic review. Health technologies are classified according to their type, purpose and clinical use; relating these to the original purpose and timing of the forecasting studies. DATA SOURCES: All health-related technologies predicted in 15 forecasting studies identified in a previously published systematic review. MAIN OUTCOME MEASURE: Outcomes related to (1) each forecasting study including country, year, intention and forecasting methods used and (2) the predicted technologies including technology type, purpose, targeted clinical area and forecast timeframe. RESULTS: Of the 896 identified health-related technologies, 685 (76.5%) were health technologies with an explicit or implied health application and included in our study. Of these, 19.1% were diagnostic or imaging tests, 14.3% devices or biomaterials, 12.6% information technology systems, eHealth or mHealth and 12% drugs. The majority of the technologies were intended to treat or manage disease (38.1%) or diagnose or monitor disease (26.1%). The most frequent targeted clinical areas were infectious diseases followed by cancer, circulatory and nervous system disorders. The most frequent technology types were for: infectious diseases-prophylactic vaccines (45.8%), cancer-drugs (40%), circulatory disease-devices and biomaterials (26.3%), and diseases of the nervous system-equally devices and biomaterials (25%) and regenerative medicine (25%). The mean timeframe for forecasting was 11.6 years (range 0-33 years, median=10, SD=6.6). The forecasting timeframe significantly differed by technology type (p=0.002), the intent of the forecasting group (p<0.001) and the methods used (p<001). CONCLUSION: While description and classification of predicted health-related technologies is crucial in preparing healthcare systems for adopting new innovations, further work is needed to test the accuracy of predictions made.

Past speculations of the future: a review of the methods used for forecasting emerging health technologies.

OBJECTIVES: Forecasting can support rational decision-making around the introduction and use of emerging health technologies and prevent investment in technologies that have limited long-term potential. However, forecasting methods need to be credible. We performed a systematic search to identify the methods used in forecasting studies to predict future health technologies within a 3-20-year timeframe. Identification and retrospective assessment of such methods potentially offer a route to more reliable prediction. DESIGN: Systematic search of the literature to identify studies reported on methods of forecasting in healthcare. PARTICIPANTS: People are not needed in this study. DATA SOURCES: The authors searched MEDLINE, EMBASE, PsychINFO and grey literature sources, and included articles published in English that reported their methods and a list of identified technologies. MAIN OUTCOME MEASURE: Studies reporting methods used to predict future health technologies within a 3-20-year timeframe with an identified list of individual healthcare technologies. Commercially sponsored reviews, long-term futurology studies (with over 20-year timeframes) and speculative editorials were excluded. RESULTS: 15 studies met our inclusion criteria. Our results showed that the majority of studies (13/15) consulted experts either alone or in combination with other methods such as literature searching. Only 2 studies used more complex forecasting tools such as scenario building. CONCLUSIONS: The methodological fundamentals of formal 3-20-year prediction are consistent but vary in details. Further research needs to be conducted to ascertain if the predictions made were accurate and whether accuracy varies by the methods used or by the types of technologies identified.

Artificial Pancreas Device Systems for the Closed-Loop Control of Type 1 Diabetes: What Systems Are in Development?

BACKGROUND: Closed-loop artificial pancreas device (APD) systems are externally worn medical devices that are being developed to enable people with type 1 diabetes to regulate their blood glucose levels in a more automated way. The innovative concept of this emerging technology is that hands-free, continuous, glycemic control can be achieved by using digital communication technology and advanced computer algorithms. METHODS: A horizon scanning review of this field was conducted using online sources of intelligence to identify systems in development. The systems were classified into subtypes according to their level of automation, the hormonal and glycemic control approaches used, and their research setting. RESULTS: Eighteen closed-loop APD systems were identified. All were being tested in clinical trials prior to potential commercialization. Six were being studied in the home setting, 5 in outpatient settings, and 7 in inpatient settings. It is estimated that 2 systems may become commercially available in the EU by the end of 2016, 1 during 2017, and 2 more in 2018. CONCLUSIONS: There are around 18 closed-loop APD systems progressing through early stages of clinical development. Only a few of these are currently in phase 3 trials and in settings that replicate real life.

Tests detecting biomarkers for screening of colorectal cancer: What is on the horizon?

AIM: To identify new and emerging screening tests for colorectal cancer (CRC) that involves detection of various biomarkers like blood, DNA and RNA in samples of faeces, tissue or blood. Current practice: Screening for CRC can be done by bowel visualisation techniques and tests that measure biomarkers. The Bowel Cancer Screening Programme (BCSP) in England uses a guaiac faecal occult blood test. METHODS: The strategy was to search available literature, identify developers and contact them for relevant information. Advice from experts was sought on potential utility and likely impact of identified technologies on the BCSP. RESULTS: Ninety-three companies and five research groups were contacted. Sixty-nine relevant tests were identified. Detailed information was available for 48 tests, of these 73% were CE marked and the remainder were considered as emerging. Forty-nine tests use immunochemical methods to detect occult blood in faeces. Eight, four and two tests detect biomarkers in a sample of blood, or exfoliated cells either shed in faeces or collected from rectal mucosa respectively. Six tests were grouped as 'other tests'. Most of the identified tests are performed manually and give qualitative detection of biomarkers. CONCLUSION: Variation in test performance and characteristics was observed amongst the 69 identified tests. Automated, quantitative FIT with a variable cut off are the preferred approach in the BSCP. However the units used to report FITs results do not enable comparison across products. Tests detecting biomarkers other than occult blood are more specific to neoplasms but have limited sensitivity due to the heterogeneity of cancer. Research is ongoing to identify an optimal panel of biomarkers, simplifying and automating the test, and reducing the cost.

EUROSCAN INTERNATIONAL NETWORK MEMBER AGENCIES: THEIR STRUCTURE, PROCESSES, AND OUTPUTS.

OBJECTIVES: The EuroScan International Network is a global network of publicly funded early awareness and alert (EAA) systems for health technologies. We describe the EuroScan member agency systems and methods, and highlight the potential for increased collaboration. METHODS: EuroScan members completed postal questionnaires supplemented with telephone interviews in 2012 to elicit additional information and check equivalence of responses. Information was updated between March and May 2013. RESULTS: Fifteen of the seventeen member agencies responded. The principal purpose of agencies is to inform decisions on coverage or reimbursement of health services and decisions on undertaking secondary research. The main users of information are national governments; health professionals; health services purchasers, commissioners, and decision makers; and healthcare providers. Most EuroScan agencies are small with almost half having fewer than two whole time equivalent staff. Ten agencies use both active and passive identification approaches, four use only active approaches. Most start identification in the experimental or investigational stages of the technology life cycle. All agencies assessed technologies when they are between the investigational and established, but under diffusion stages. Barriers to collaboration revolve around different system aims, purposes, and requirements; a lack of staff, finance, or opportunity; language differences; and restrictions on dissemination. CONCLUSIONS: Although many barriers to collaboration were identified, the majority of agencies were supportive of increased collaboration either involving the whole EuroScan Network or between individual agencies. Despite differences in the detailed identification processes, members thought that this was the most feasible phase to develop additional collaboration.

Regenerative medicine techniques in cardiovascular disease: where is the horizon?

Regenerative medicine techniques to restore cardiac and vascular function are being increasingly investigated as management options for cardiovascular disease. The authors set out to identify emerging regenerative techniques in cardiovascular disease and investigate their stage of development. The relevant networks in the field in the UK were contacted and online sources for cell therapy, tissue engineering, and other regenerative techniques and products were searched for online. A total of 49 Phase II, II/III and III trials of regenerative products or techniques were identified: 13 Phase III, eight Phase II/III and 28 Phase II trials. Twelve of the Phase III trials are for myocardial ischemia and involve an intracoronary infusion or intramyocardial injection of autologous bone marrow-derived stem cells. Most of those in Phase III trials are, however, associated either with an unproven delivery technique or cellular approach. The authors conclude that translation into clinical practice and diffusion into health systems is some way off.

Decline in new drug launches: myth or reality? Retrospective observational study using 30 years of data from the UK.

OBJECTIVE: To describe trends in new drugs launched in the UK from 1982 to 2011 and test the hypothesis that the rate of new drug introductions has declined over the study period. There is wide concern that pharmaceutical innovation is declining. Reported trends suggest that fewer new drugs have been launched over recent decades, despite increasing investment into research and development. DESIGN: Retrospective observational study. SETTING AND DATA SOURCE: Database of new preparations added annually to the British National Formulary (BNF). MAIN OUTCOME MEASURES: The number of new drugs entered each year, including new chemical entities(NCEs) and new biological drugs, based on first appearance in the BNF. RESULTS: There was no significant linear trend in the number of new drugs introduced into the UK from 1982 to 2011. Following a dip in the mid-1980s (11-12 NCEs/new biologics introduced annually from 1985 to 1987), there was a variable increase in the numbers of new drugs introduced annually to a peak of 34 in 1997. This peak was followed by a decline to approximately 20 new drugs/year between 2003 and 2006, and another peak in 2010. Extending the timeline further back with existing published data shows an overall slight increase in new drug introductions of 0.16/year over the entire 1971 to 2011 period. CONCLUSIONS: The purported 'innovation dip' is an artefact of the time periods previously studied. Reports of declining innovation need to be considered in the context of their timescale and perspective.

The future role of genetic screening to detect newborns at risk of childhood-onset hearing loss.

OBJECTIVE: To explore the future potential of genetic screening to detect newborns at risk of childhood-onset hearing loss. DESIGN: An expert led discussion of current and future developments in genetic technology and the knowledge base of genetic hearing loss to determine the viability of genetic screening and the implications for screening policy. RESULTS AND DISCUSSION: Despite increasing pressure to adopt genetic technologies, a major barrier for genetic screening in hearing loss is the uncertain clinical significance of the identified mutations and their interactions. Only when a reliable estimate of the future risk of hearing loss can be made at a reasonable cost, will genetic screening become viable. Given the speed of technological advancement this may be within the next 10 years. Decision-makers should start to consider how genetic screening could augment current screening programmes as well as the associated data processing and storage requirements. CONCLUSION: In the interim, we suggest that decision makers consider the benefits of (1) genetically testing all newborns and children with hearing loss, to determine aetiology and to increase knowledge of the genetic causes of hearing loss, and (2) consider screening pregnant women for the m.1555A> G mutation to reduce the risk of aminoglycoside antibiotic-associated hearing loss.

Burden of disease, research funding and innovation in the UK: Do new health technologies reflect research inputs and need?

OBJECTIVES: New and emerging health technologies (innovation outputs) do not always reflect conditions representing the greatest disease burden. We examine the role of research and development (R&D) funding in this relationship, considering whether areas with fewer innovative outputs receive an appropriate share of funding relative to their disease burden. METHODS: We report a retrospective observational study, comparing burden of disease with R&D funding and innovation output. UK disability-adjusted life years (DALYs) and deaths came from the World Health Organization (WHO) 2004 Global Burden of Disease estimates; funding estimates from the UK Clinical Research Collaboration's 2006 Health Research Analysis; and innovation output was estimated by the number of new and emerging technologies reported by the National Institute for Health Research (NIHR) Horizon Scanning Centre between 2000 and 2009. RESULTS: Disease areas representing the biggest burden were generally associated with the most funding and innovation output; cancer, neuropsychiatric conditions and cardiovascular disease together comprised approximately two-thirds of DALYs, funding and reported technologies. Compared with DALYs, funding and technologies were disproportionately high for cancer, and technologies alone were disproportionately high for musculoskeletal conditions and endocrine/metabolic diseases. Neuropsychiatric conditions had comparatively few technologies compared to both DALYs and funding. The relationship between DALYs and innovation output appeared to be mediated by R&D funding. CONCLUSIONS: The relationship between burden of disease and new and emerging health technologies for different disease areas is partly dependent on the associated level of R&D funding (input). Discrepancies among key groups may reflect differential focus of research funding across disease areas.

Early awareness and alert systems: an overview of EuroScan methods.

OBJECTIVES: Early awareness and alert (EAA) activities are increasingly recognized to be an important component of the health technology assessment (HTA) process. Sharing information on methods used in this discipline is vital to ensure the development of sustainable systems. The objectives of this study is to outline the approach taken to share the different methods that members of the EuroScan International Network use by producing a methods toolkit; and to provide an overview of the similarities and differences in methods adopted by EAA systems. METHODS: A Delphi technique was used to develop the methods toolkit. Structured questionnaires were used to identify the sources used in the identification of emerging technologies and to determine the methods used by agencies to carry out EAA activities. RESULTS: A methods toolkit incorporating guidance on all of the stages described by EuroScan members was produced. The toolkit and an accompanying checklist presents users with different methods that can be adopted to suit their needs. The comparative analysis demonstrates that different methods are being used by EAA systems dependent on resources available and customer requirements. Differences in identification, filtration, prioritization, and assessment are apparent along with the role of collaborators in these processes. CONCLUSIONS: The methods used by EAA systems are not homogeneous resulting in a toolkit constructed on the basis of "one size doesn't fit all." Methods in this discipline are developing continually to accommodate changes in health systems and the HTA world. Differences between agencies and the sharing of ideas and experiences enable EAA agencies to adapt to these developments.

Innovation and the burden of disease: retrospective observational study of new and emerging health technologies reported by the EuroScan Network from 2000 to 2009.

OBJECTIVES: Medical innovation in developed countries has been linked to burden of disease, with more innovation in areas representing greater investment return. This study used horizon scanning or early awareness and alert activity as a novel measure of innovation to determine whether new and emerging health technologies reported by international horizon scanning agencies reflected diseases constituting the greatest burden. METHODS: This was a retrospective observational study of the 20 member agencies of EuroScan (the International Information Network on New and Emerging Health Technologies), representing 17 developed countries. Burden of disease was defined as disability-adjusted life-years, taken from the 2004 World Health Organization Global Burden of Disease estimates. This analysis focused on 102 specific diseases within 21 broader groups. Horizon scanning output was measured as the number of technologies reported by EuroScan member agencies between 2000 and 2009. RESULTS: At best there was a weak association between innovation and burden of disease. An apparent high-level association was dependent on just three high-prevalence disease groups: malignant neoplasms, neuropsychiatric conditions, and cardiovascular disease. Disaggregating broader groups into specific diseases further weakened the association. Innovation is disproportionately strong in cancer and nonischemic heart disease and disproportionately weak in mental health. CONCLUSIONS: Innovations reported by early awareness and alert systems do not always reflect conditions accounting for the highest morbidity and mortality. The results do not support previous reports of a positive relationship between burden of disease and innovation, but accord with evidence of notable discrepancies among key groups. Factors other than disease burden drive innovation.

Emerging point of care tests for influenza: innovation or status quo.

BACKGROUND: Point of care tests (POCTs) for influenza potentially offer earlier diagnosis, enabling specific treatment, infection control measures and greater patient convenience and satisfaction. Current POCTs have limited sensitivity, some cannot distinguish influenza types, none differentiate subtypes and are relatively expensive. AIMS: To identify and characterise influenza POCTs expected to be available for clinical use in the U.K. by mid-2013, highlighting those with potential benefits over existing tests. METHODS: Potential developers of influenza POCTs were identified through known manufacturers' websites, Medical Technology trade associations, the EuroScan International Network, an expert advisory group and by searching relevant online sources. Identified companies were asked to provide standard information on relevant technologies. RESULTS: Fifty-six companies were identified, and 29 (52%) responded, identifying 57 potentially relevant technologies. Of these, 40 (70%) were already available or had undetermined status and 5 (9%) were excluded as time to results took over 60 minutes. Of the remaining 12 emerging POCTs, 10 (83%) reportedly enabled differentiation of influenza types and eight differentiation of A subtypes. Nasopharyngeal swabs were the most commonly acceptable sample type; the sample volume ranging from 80 µl to 1.4 ml. DISCUSSION: Most identified emerging influenza POCTs offered differentiation of influenza type and subtype. Tests claiming this capability include several incorporating reverse transcription polymerase chain reaction assays; though, these also had the longest time to result. However, whilst some identified POCTs exhibit high sensitivity and specificity, most lack published clinical data for assessment, and the overall costs of these technologies remains largely unknown.

Identification of innovation in public health.

BACKGROUND: The National Horizon Scanning Centre provides national policy-makers in England with forewarning about emerging and new health technologies. This includes public health interventions (PHIs) but identification of these interventions is not always easy. OBJECTIVES: The aim of this study was to explore the meaning and define innovation in public health. METHODS: We used a quasi-Delphi method with questionnaire 1 sent to 106 public health and horizon scanning professionals and decision-makers in June 2008. Questionnaire 2 was developed based on answers to questionnaire 1 and sent to all respondents. RESULTS: A definition of innovative PHIs was developed: 'Innovative PHIs are generally new and different to established interventions. They should be equitable, applicable to all in a population, cost-effective and may address health determinants in the non-health sector of society. A good evidence base is ideal, but sometimes it may be necessary to consider PHIs lacking evidence'. Sources suggested for identifying innovative PHIs were similar to those used for other types of health technologies. CONCLUSION: Our findings should help early awareness and alert systems distinguish innovative from non-innovative PHIs, although its application in practice needs trialling.

Information service on new and emerging health technologies: identification and prioritization processes for a European union-wide newsletter.

OBJECTIVES: EUnetHTA WP 7 (Strand B) aimed to promote sharing information on new and emerging technologies. The task was to develop a prototype of a newsletter and pilot the processes of production. METHODS: The EuroScan database served as information source on pertinent technologies. To prioritize, a set of criteria for scoring the potential impact and for selecting the technologies for articles was applied and a pilot newsletter was produced. RESULTS: Being objective and transparent about the content of a newsletter required a method for prioritizing health technologies. Using significance criteria, members of the prioritization panel selected twelve technologies for articles of different length and depth. Potential recipients, surveyed on relevance, content, timeliness, and readability responded mostly positive, but requested more information on cost effectiveness and criticized timeliness. CONCLUSIONS: Dissemination of an EU-wide newsletter would be feasible, but time-consuming. Although a newsletter appears to fulfill a need for information on emerging and new health technologies, it is not considered the right tool to avoid duplication of effort in the present international constellation of horizon scanning for new health technologies. Other options will be pursued as part of future collaborative actions, for example, a core set of early awareness information, or an on-demand electronic information system.

Early identification and assessment of new and emerging health technologies: actions, progress, and the future direction of an international collaboration--EuroScan.

OBJECTIVES: To report on a workshop, and subsequent discussions, that reviewed the achievements and progress of the EuroScan collaboration since its establishment in 1999 to share information on the methods and results of early identification and assessment of new and emerging health technologies; considered challenges to the collaboration; and discussed its possible future direction. METHODS: A workshop was held in Stockholm in September 2006, with thirty-two participants from ten countries and representatives from EuroScan member agencies, policy makers involved in policy or decision making relating to new technologies, and invited external commentators from international HTA networks. The workshop used a mix of presentations, panel and audience discussions, and small group work to consider the achievements and challenges put forward. RESULTS: EuroScan has developed as a sustainable network, and has made progress on all tasks in its initial action plan, with the EuroScan information sharing database on new and emerging technologies being one of the collaboration's key achievements. Identified immediate concerns for the network included consideration of the impact of its current name and membership model; acknowledgement and publication of the full range of benefits of membership; contribution to and development of the database to encourage increased information sharing; and EuroScan's ongoing interaction with the wider HTA world. CONCLUSIONS: The workshop was a useful mechanism for reviewing the work of EuroScan and for creating a platform to take the collaboration forward. The workshop affirmed the benefits of the network to individual members; posed some significant challenges to the network to consider; and acted as a stimulus for an interim name change to better represent the global membership, and a major review of the EuroScan database of identified and assessed emerging health technologies.

Effective early warning systems for new and emerging health technologies: developing an evaluation framework and an assessment of current systems.

OBJECTIVES: The aim of this study was to define an effective early warning system, to identify and rank the characteristics of an effective early warning system for emerging health technologies, and to evaluate current early warning systems against these characteristics. METHODS: An iterative Delphi-type process with the thirteen members of the International Information Network on New and Changing Health Technologies (EuroScan). We synthesized key characteristics that network members had graded. Members were then asked whether these characteristics were present or fulfilled in their system. RESULTS: The definition of an effective early warning system developed was the following: a system that identifies innovations in the field of health technology likely to have a significant impact; and disseminates information relevant to the needs of the customer which is timely, so as to enable appropriate decision making (such as resource allocation), facilitate appropriate adoption, and identify further research requirements. Five primary and eleven secondary components of effective early warning systems were identified. The five primary characteristics concerned relevance, independence, resourcing, a clear pathway for the outputs to reach decision makers, and defined customers. Although the primary characteristics were present or fulfilled to some extent in the majority of evaluated early warning systems, there was considerable variability in the presence of the secondary characteristics in the evaluated systems. CONCLUSIONS: Our study provides a definition for an effective early warning system and a shared understanding of the important characteristics and components of such systems. This work should provide guidance to those setting up new early warning systems as well as for those managing and reviewing current systems.

International diffusion of new health technologies: a ten-country analysis of six health technologies.

OBJECTIVES: The objective of this study was to examine and explain the differential international diffusion of six health innovations. METHODS: A retrospective diffusion study was undertaken of sildenafil, cyclooxygenase-II (COX II) inhibitors, beta interferon, verteporfin, deep brain stimulators, and drug-eluting coronary stents in ten countries-Australia, Canada, Denmark, France, The Netherlands, Norway, Spain, Sweden, Switzerland, and the United Kingdom. We plotted diffusion curves of daily defined doses per quarter, vials or implants per million population, and examined the association between diffusion and five key variables. RESULTS: Canada, Switzerland, and Sweden are generally high users of new technologies; Spain, Denmark, and particularly the United Kingdom are low users. Almost all countries experienced rapid adoption of sildenafil with diffusion to a similar level; there was variable adoption and diffusion of COX II inhibitors, verteporfin, and interferon beta; drug-eluting stents penetrated the market in a similar way in all but one country; and two countries had very different adoption patterns for deep brain stimulators. Above average health spending and the presence of health technology assessment (HTA) or other guidance reports are consistently associated with increased diffusion. Early warning activity and a national coverage decision being taken are more likely to be associated with a reduced diffusion. CONCLUSIONS: The significant differences in diffusion between different countries are not consistent with a neat evidence-based world. The tools available to policy makers to control diffusion (early warning systems, HTA, and a fourth hurdle) play some part in influencing diffusion but need close scrutiny of how successfully they operate.

Predicting the impact of new health technologies on average length of stay: development of a prediction framework.

OBJECTIVES: The aim of this study was to develop a framework to predict the impact of new health technologies on average length of hospital stay. METHODS: A literature search of EMBASE, MEDLINE, Web of Science, and the Health Management Information Consortium databases was conducted to identify papers that discuss the impact of new technology on length of stay or report the impact with a proposed mechanism of impact of specific technologies on length of stay. The mechanisms of impact were categorized into those relating to patients, the technology, or the organization of health care and clinical practice. RESULTS: New health technologies have a variable impact on length of stay. Technologies that lead to an increase in the proportion of sicker patients or increase the average age of patients remaining in the hospital lead to an increase in individual and average length of stay. Technologies that do not affect or improve the inpatient case mix, or reduce adverse effects and complications, or speed up the diagnostic or treatment process should lead to a reduction in individual length of stay and, if applied to all patients with the condition, will reduce average length of stay. CONCLUSIONS: The prediction framework we have developed will ensure that the characteristics of a new technology that may influence length of stay can be consistently taken into consideration by assessment agencies. It is recognized that the influence of technology on length of stay will change as a technology diffuses and that length of stay is highly sensitive to changes in admission policies and organization of care.