Bed Utilization Efficiency Research Articles

Comparison of effectiveness indicators before and during the COVID-19 pandemic in a university hospital

Objective: Our aim in this study is to reveal to what extent hospital efficiency indicators changed in a University Hospital between the period before the Covid 19 pandemic (2018-2019) and the period when the pandemic started and continued (2020-2021). Method: The study planned as a retrospective and descriptive type, data belongs to a 4-year period (2018-2021). The number of personnel for the years examined in the study, the number of applications to the outpatient clinic and emergency department calculated monthly and the number of deceased patients. Bed occupancy rate, inpatient rate, average patient stay days, bed turnover rate and bed turnover interval were used as hospital bed utilization efficiency indicators. Result: Among all years, April 2020 had the lowest number of emergency applications (n=1287) and total number of outpatient clinic applications (n=7530). The year with the highest bed occupancy rate was 2020 with 77.2±6.7. The highest inpatient rate was in 2020 with 6.7±2.1, the highest average day of stay was in 2021 with 10.8±2.2, the highest bed turnover rate was in 2018 and 2019 with 4.7±0.3 and the highest bed turnover interval was observed in 2021 with 5.2±2.2. April 2020 was the month with the highest inpatient rate at 11.8% and the highest bed turnover interval at 16.8. Conclusion: The number of patients applying to emergency departments and outpatient clinics decreased, the inpatient rate increased, the bed turnover rate decreased, the bed turnover interval extended and the average day of stay increased during the pandemic period.

Exploration of the adsorption and desorption performance of volatile organic compounds by activated carbon with different shapes based on fixed-bed experiments

Activated carbon (AC) has been widely used in volatile organic compounds (VOCs) treatment of industrial exhaust gases. Rather than modifying specific pore size distributions and surface properties, altering the shape of AC offers a more feasible approach to enhance its adsorption performance. This study investigates the adsorption-desorption performance of two different shaped ACs with highly similar properties for the removal of VOCs. The clover-shaped AC (CSAC) has a 27.46% lower internal void fraction and a 39.10% higher external void fraction compared to cylindrical AC (CAC), resulting in denser packing and longer contact time with VOCs. Adsorption experiments showed the CSAC has 40% longer adsorption breakthrough (BT) times for ethanol, ethyl acetate, and n-hexane on average, and 20% higher saturation adsorption capacity per unit volume. CSAC also has higher partition coefficients, with the highest values for ethanol, ethyl acetate, and n-hexane being 0.0187, 0.0382, and 0.0527 mol kg−1·Pa−1, respectively. The desorption process for selected VOCs is non-spontaneous and endothermic. Optimal desorption conditions were identified as an inlet space velocity of 3535 h−1, a desorption temperature of 150 °C, and a pulsed inlet method. To investigate the possibility of the application of CSAC in real-world scenarios, xylene was chosen as a representative industrial VOC. Results showed CSAC has 20% higher BT time and saturation adsorption capacity for xylene compared to CAC under different bed heights. The desorption efficiency for xylene on both ACs is below 40%. With increasing xylene inlet concentration, the mass transfer zone (MTZ) height initially increases but stabilizes beyond 1704 mg m−3. At identical bed heights, the MTZ height of CSAC is 29% shorter than CAC, indicating a higher bed utilization efficiency.

The Application of Microfibrous Entrapped Activated Carbon Composite Material for the Sarin Simulant Dimethyl Methylphosphonate Adsorption.

Granular activated carbon (GAC) has proven to be an effective adsorbent for removing the chemical warfare agent sarin (GB) and simulants like Dimethyl methylphosphonate (DMMP). However, it comes with certain limitations, including inadequate contact efficiency, notable mass transfer resistance, and lower bed utilization efficiency. This study synthesized steel fiber-entrapped activated carbon composites (SFEACs), which exhibited a maximum adsorption capacity of 285.3 mg/g at 303 K. Compared with the packed bed (PB) filled with GAC, while the adsorption capacity of SFEACS decreased, there was a substantial increase in the adsorption mass transfer rate. These SFEACs were combined with GAC to create a structural fixed bed (SFB), which demonstrated excellent performance in DMMP removal. Under identical experimental conditions, the DMMP breakthrough curve of SFB exhibited a steeper profile compared to the packed bed (PB) filled with GAC at the same bed height, and the breakthrough time against DMMP vapor could be extended by 13.8%. Furthermore, the adsorption rate constant of the Yoon-Nelson model increased by more than 17.6%, and the unused bed length, according to the Wheeler-Jonas model, decreased by more than 14%.

Efficiency and equity of bed utilization in China’s health institutions: based on the rank-sum ratio method

ObjectiveThe study aimed to analyze the efficiency and equity of bed utilization in Please check if the section headings are assigned to appropriate levels.China’s healthcare institutions and to compare and analyze the overall health resource utilization efficiency in recent years and some specific utilization conditions in 2021, to provide empirical experience for the allocation of health care resources in epidemic China.MethodsTo compare and analyze the overall health resource utilization efficiency of the whole country with that of the East, middle, and West in 2021, and to analyze the bed utilization efficiency of different types of healthcare institutions in China and the bed utilization efficiency of various types of specialist hospitals in the country in 2021 by using the rank-sum ratio method.ResultsIn 2021, the bed utilization rate of China’s health institutions was 69.82%, and the number of bed turnover times was 27.65 times; the bed utilization rate of hospitals was 74.6%, and the number of bed turnover times was 26.08 times. The number of hospital bed turnovers was highest in the western region, lowest in the central region, and close to the national average in the eastern region. The average length of stay for discharged patients was the highest in the central region, the lowest in the eastern region, and the same as the national average in the western region. The analysis of rank-sum ratio method shows that among different types of health institutions’ bed utilization efficiency (r = 0.935, P = 0.000), general hospitals and traditional Chinese medicine hospitals have the best bed utilization rate, and the bed utilization rate of community health service centers (stations) needs to be improved; while among various types of specialized hospitals’ bed utilization efficiency (r = 0.959, P = 0.000), oncology hospitals, thoracic hospitals, and hematology hospitals, children’s hospitals have high bed utilization efficiency; leprosy hospitals, cosmetic hospitals, and stomatology hospitals have low bed utilization efficiency. Health technicians per 1,000 population are highest in the western region, lowest in the central region, and lower in the eastern region than in the western region but slightly higher than the national average. The number of beds in health institutions per 1,000 population is the highest in the central region, the lowest in the eastern region, and slightly lower in the northwest than in the central region but higher than the national average.ConclusionChina’s investment in health funding in the field of health care has been on the rise in recent years. However, there still exists the situation of uneven investment in health expenses and inconsistent medical efficiency among regions. And change such a status quo can be further improved in terms of government, capital, human resources, technology, information system, and so on.

Dynamics of indicators of bed fund of offices of anesthesiology and resuscitation in the Russian Federation

Introduction. Efficient bed fund management is one of the most important conditions for an appropriate management of healthcare provision. The aim of the study is to analyze the trend in anesthesiologic and intensive care unit bed capacity in federal districts (FD) and subjects of the Russian Federation for 2014-2018. Material and methods. We analyzed the indicators of intensive care beds use (availability of beds to population, hospitalization rate, duration of patient’s stay in intensive care bed, occupancy, bed turnover, mortality) according to federal statistical observation - forms No. 14 and No. 30. Results. In Russia, the provision of beds in the health care sector has been decreasing over the last decade. At the same time, resuscitation beds were not affected by such changes, and from 2014 to 2018 the number of resuscitation beds tended to increase by 80.8%, which is associated, among other things, with the changes in the methodology of formation of the annual reporting form №30. The following changes in indicators of intensive care beds use were revealed in the trend in the Russian Federation as a whole for 2014-2018: the hospitalization rate slightly increased by 28.6% (from 0.5 to 0.7); provision of the population with intensive care beds (per 10,000 population) tends to increase by 45.8% population) tends to increase by 45.1% (from 1.1 to 2.0); length of stay of the patient on average increased by 23.9% (from 7.0 to 9.2 days); average occupancy (bed work) tends to decrease from 254 to 247 days; bed turnover tends to decrease from 36.1 to 26.9; mortality rate increases from 30.2 to 46.9%. Limitations. The results of the study of the dynamics of anesthesiologic and intensive care unit bed capacity are only valid for the Federal districts and Federal subjects of the Russian Federation. Conclusions. Additional studies are needed to further objectivize the assessment of ICU bed utilization efficiency.

Yoğun Bakım Yatak Kullanım Verimliliğinin Pabon Lasso Modeli İle Değerlendirilmesi

Hastanelerde sunulan sağlık hizmetleri, sağlık sistemlerinin en pahalı ve en önemli parçasıdır. Önemli maliyet girdileri oluşturmaktadır. Bu nedenle kıt olan kamu kaynaklarının etkin ve verimli kullanılması, atıl durumdaki kaynakların tespit edilmesi ve performans değerlendirmesinin yapılması önem arz etmektedir. Bu araştırmanın amacı, yoğun bakım yatak kullanım etkinliğinin Pabon Lasso modeli (PLM) ile incelenmesidir. Araştırma retrospektif ve kesitsel olarak 2017 ve 2018 yılını kapsamaktadır. Araştırmaya bir eğitim araştırma hastanesinde hizmet veren tüm yoğun bakım üniteleri (YBÜ) dâhil edilmiştir. Araştırmada yoğun bakım ünitelerinin yatak kullanımı etkinliğini tespit edebilmek için yatak doluluk oranı (YDO), yatak devir hızı (YDH) ve ortalama kalış süresi (OKS) değişken olarak kullanılmıştır. Araştırmada kullanılan iki yıllık veriler Temel Sağlık İstatistikler Modülünden (TSİM) elde edilmiştir. Verilerin analizinde Macromedia ve MS Excel yazılımlarından yararlanılmıştır. Araştırmadan elde edilen bulguları sonucunda yoğun bakım ünitelerinin yatak doluluk oranı, yatak devir hızı ve ortalama kalış sürelerinde 2017 yılına kıyasla 2018 yılında artış olduğu tespit edilmiştir. 2017 yılında yoğun bakımların %30’u verimli verimli bölgede iken, 2018 yılında %20’sinin verimli bölgede olduğu saptanmıştır. Yine 2017 yılında verimsiz olarak nitelendirilen 1. bölge yoğun bakımların %30’u yer alırken 2018 yılında bu oranın %20’ye düştüğü tespit edilmiştir. Her iki yılda bazı yoğun bakım ünitelerinin modelde değişken olarak kullanılan performans göstergeleri incelendiğinde ;en az biri açısında düşük performans gösterdiği saptanmıştır. Pabon Lasso modeli, yatak kullanım performansı hakkında hızlı ve anlamlı bilgiler vermektedir. Bu modelin yatak kullanım etkinliğinin ölçülmesinde diğer performans ölçüm yöntemlerinin yanı sıra kullanılması tavsiye edilmektedir.

Comprehensive evaluation on bed utilization efficiency of public TCM hospitals in 17 cities of Hubei province

To evaluate the bed utilization efficiency of public TCM hospitals in 17 cities of Hubei Province, the date of the bed utilization of public TCM hospitals in 17 cities of Hubei Province in 2017 was collected. Then, the entropy weight method was used to determine the weight of evaluation indicators, and the method of TOPSIS and RSR were used to evaluate bed utilization efficiency. The bed utilization efficiency of public TCM hospitals in 17 cities of Hubei Province can be divided into three levels. Ezhou, Yichang were in lower range, Huanggang, Enshi, Jingmen, Huangshi, Tianmen, Wuhan, Qianjiang, Xiangyang, Xianning, Shiyan, Shenlongjia, Xiantao were in midrange and Jingzhou, Suizhou, Xiaogan were in higher range. The method of entropy weight TOPSIS and RSR can reflect the bed utilization efficiency of public TCM hospitals in different cities objectively and comprehensively, and the results are scientific and reliable. There is a big gap in the bed utilization efficiency of public TCM hospitals in cities of Hubei Province. It is suggested that cities with low bed utilization efficiency should give full play to the characteristics and advantages of TCM to improve the core competitiveness of hospitals and to enhance the attractiveness of hospitals to patients. At the same time, public TCM hospitals should deepen the integration of TCM and Internet, and optimize the medical service process of TCM to improve the bed utilization efficiency.

Adsorptive filtration of lead by electrospun PVA/PAA nanofiber membranes in a fixed-bed column

Poly(vinyl) alcohol/poly(acrylic) acid (PVA/PAA) nanofiber membranes were fabricated using electrospinning and showed good water stability and mechanical strength. Their application in lead (Pb(II)) removal from water was evaluated in a continuous fixed-bed column under varying conditions. The filtration was more efficient with a low feed concentration and low flow rate in terms of the elevated adsorption capacity and better bed utilization efficiency. The dynamic adsorption process was independent of bed height, so the fibers can be used as multilayer membranes in a fixed-bed column. The saturated column material could be regenerated and reused. The breakthrough curves were well fitted with the dose-response model, and the maximum adsorption capacity was 288 mg/g with the initial Pb(II) concentration of 1 mg/L. When tap water was used, the amount of water that can be treated before the effluent reached 15 μg/L increased by three times compared to the treatment of NaCl solutions, and a very high improvement was observed at pH 7 (4.5 L) than pH 5 (2.0 L) in tap water. These differences were further confirmed by the extended X-ray absorption fine structure (EXAFS) spectroscopy, where a decreased coordination number and decreased interatomic distance between Pb and C were observed for tap water. This study provides valuable insights in the application of PVA/PAA nanofiber membranes in a dynamic system for Pb(II) removal, and sheds light on the interatomic behavior between Pb(II) and the nanofiber membranes in a flow-through system.

Sintered metal fibers@carbon molecular sieve membrane (SMFs@CMSM) composites for the adsorptive removal of low concentration isopropanol

Structured fixed-bed adsorber based on SMF@CMSM adsorbents show enhanced mass transfer and 3 bed utilization efficiency.

A mass transfer model for the fixed-bed adsorption of ferulic acid onto a polymeric resin: axial dispersion and intraparticle diffusion

ABSTRACTIn this study, amberlite XAD-16 (XAD-16) bed column system was used to remove ferulic acid (FA) from aqueous solutions. Laboratory-scale column experiments were conducted in downflow fixed bed at initial FA concentration of 1 g/L, initial pH 3, and 25°C. The performance of the adsorbent bed under different flow rates (1.3–7.7 mL/min) was studied. The bed utilization efficiency was in the range of 64.64–72.21% at the studied flow rates. A mass transfer model considering both axial dispersion and intraparticle diffusion was developed to predict the breakthrough curves of FA adsorption on XAD-16. This model predicted the experimental data better than Bohart–Adams model and Thomas model, based on the low deviation between predicted and experimental data. The axial dispersion coefficient value varied from 6.45 × 10−6 to 1.10 × 10−6 m2/s at flow rate from 1.3 to 7.7 mL/min, whereas the intraparticle diffusion coefficient was 1.04 × 10−10 m2/s, being this last resistance the rate-limiting step. In conclusion, axial dispersion and intraparticle diffusion phenomena play the major role in predicting the adsorption of FA onto XAD-16 in fixed-bed columns.

Hospital bed efficiency analysis of medical institutions in Henan province

Objective Different methods were used for the analysis of different medical and health institutions in Henan Province in 2012 of hospital bed utilization, to find bed utilization problems, and provide reference for the rational allocation of resources. Methods Static beds utilization model method(SBMA)and the method of rank sum ratio(RSR)were used for planning of data in2012 health statistics yearbook of Henan province, for comprehensive analysis of bed utilization efficiency. Results Among the medical and health institutions in Henan province in 2012, general hospitals, maternal and children hospitals(centers)are found with higher utilization of hospital beds, while other institutions(nursing homes), community health service centers(stations)are found lower. Conclusion Henan Province in 2012 was found on the whole with efficient utilization of hospital beds, yet with rooms of improvement for different medical institutions, especially those at the primary level. Key words: Static beds utilization model; Rank sum ratio; Hospital bed utilization efficiency

Using a Strong Anion‐Exchange Resin to Deacidify Red Palm Oil

AbstractThis work aims to evaluate the use of an alternative process to deacidify palm oil using a strong anion‐exchange resin (Amberlyst A26 OH). The effects of the feed flow rate and the free fatty acids content in the feed stream were investigated by measuring breakthrough curves for bleached palm oil dissolved in n‐propanol. The resin had sufficient capacity and affinity to remove palmitic and oleic acids (98–99 %). The bed utilization efficiency can be optimized by choosing lower flow rates for oils with low levels of acidity, while higher flow rates can be used for oils with higher free fatty acids content. The ion‐exchange process can be used to obtain deacidified red palm oil, while preserving carotenoid and tocopherol/tocotrienol content. This alternative process has the advantage of occurring under mild conditions (44.0 ± 0.8 °C and atmospheric pressure) when compared with the conditions used in molecular distillation (150.0–170.0 °C and 2.7–3.3 Pa).

Deacidification of Soybean Oil by Ion Exchange

This work investigated the deacidification of soybean oil by ion exchange using a fixed bed loaded with the strong anionic resin Amberlyst A26 OH. Degummed soybean oil was dissolved in isopropanol and the deacidification process was studied according to an experimental design based on two factors, the feed flow rate and its content of free fatty acids. The responses of interest were the solute recovery efficiency and the bed utilization efficiency, both calculated from breakthrough curves. Oil samples before and after deacidification by ion exchange, as well as samples deacidified in the industrial plant by the chemical method, were characterized according to the usual indexes for quality and identity. The results revealed that the flow rate was an important and statistically significant factor with 95 % of confidence. The deacidification by ion exchange decreased the oil acidity and also removed undesirable compounds, such as phospholipids and peroxides. However, a decrease in the concentration of tocopherol was also observed.

Hospital utilization, efficiency and access to care during and shortly after restructuring acute care in Newfoundland and Labrador

Since the 1990s restructuring, including regionalization and downsizing, has largely been driven by a desire for cost containment. Regionalization, hospital closure and changes in management processes occurred in Newfoundland and Labrador (NL), Canada between 1995 and 2000. The objectives of the current study were: to describe trends in the utilization of acute care hospital services by residents of NL during and shortly after restructuring; to examine trends in the efficiency of utilization of acute care beds in the province during the same time frame; and to compare the trends in St John's with the rest of the province, taking account of confounding events, in an attempt to understand the impact of aggregation of hospitals in this region. Hospital discharge and day surgical data were analysed for all facilities in NL from 1995/96 to 2000/01. Analyses were by facility of service and also by region of residence directly standardized to the provincial population for 1996. Efficiency of bed utilization was examined on three occasions by concurrent utilization review using a modified version of the Appropriateness Evaluation Protocol. Trends in the St John's region (where most tertiary services are located and greater aggregation of hospitals occurred) were compared with the rest of the province. Admissions declined by 14% in St John's facilities and by 17% elsewhere. Inpatient days fell by 9% in St John's and by 12% elsewhere. Average length of stay and Resource Intensity Weight changed little, apart from a rise in the final study year, with the largest change in St John's. Standardized hospital admission rates declined by 10% and inpatient days by 5.6% for residents of St John's region, and by 16% and 14% respectively for residents of other regions. There was no change over time in the use of day surgery. Efficiency of acute care bed use improved in 2002 in St John's, but was unchanged in other regions. Use of acute care beds by elderly patients for extended stay, or when an alternate level of care would have been appropriate, was greater in St John's with the disparity persisting over time. Waiting time for continuing care in the St John's region was unchanged comparing 1995/96 and 1999/00. The degree to which acute care restructuring or financial pressures and constraints imposed at the provincial level contributed to observed utilization trends is unclear. Aggregation of hospitals in the St John's region may have contributed to more efficient use of acute care beds. Restructuring as carried out did not integrate health care sectors, and problems at the acute care/continuing care boundary were not resolved in St John's, where access to continuing care remained difficult.

Quantification of factors contributing to length of stay in an acute psychogeriatric ward.

To identify variables that predict length of stay (LOS) in an acute psychogeriatric ward; quantify psychiatric, medical and social factors that contribute to LOS; and identify factors that prolong LOS. Prospective audit of admissions over 12 months. Acute psychogeriatric ward in teaching hospital. 73 consecutive patients with a total of 88 admissions. Main psychiatric, medical and social reasons for admission; Physical Health Schema; total LOS; number of days attributable to psychiatric, medical, social and treatment (non-response and adverse reactions) reasons; DSM-IV diagnosis; global clinical outcome; discharge living arrangements; discharge psychotropic medication. Presence of depressive symptoms was the most common psychiatric reason for admission and carer stress the main social reason for admission. Principal diagnosis of major depression and carer stress were significant predictors of LOS and accounted for 24.3% of the variance (p < 0.0001). Physical health and psychiatric comorbidity were not able to predict LOS. The proportion of psychiatric, medical and social reasons involved in LOS varied significantly by principal diagnosis (p < 0.001). Almost 42% of bed days were attributable to delays--for medical, social (eg placement problems), treatment (adverse events, non-response) or hospital system reasons. The quantification of factors contributing to LOS in an acute psychogeriatric unit allows for more accurate identification of issues that can be addressed to improve the efficiency of bed utilization.

Early "Step-Down" Transfer of Low-Risk Patients with Chest Pain

To determine whether providing private practitioners with triage criteria for their low-risk chest pain patients would safely enhance bed utilization efficiency in coronary and intermediate care units. Prospective, controlled, interventional trial using an alternate month study design. A large teaching community hospital. Cohort of 404 low-risk patients with chest pain for whom a diagnosis of myocardial infarction has been excluded and who have not sustained complications, required interventions, or developed unstable comorbidity. During intervention months, private practitioners caring for low-risk patients in the coronary and intermediate care units were contacted 24 hours after admission. Physicians were informed that the transfer of low-risk patients to nonmonitored beds could probably be done safely, based on the results of a pilot study. The practitioner had the option of agreeing to or deferring patient transfer. During control months, physicians were not contacted in this way. Use of the triage criteria by private practitioners reduced lengths of stay in the intermediate and coronary care units by 36% and 53%, respectively. Bed availability increased by 744 intermediate and 372 coronary care unit bed-days per year. Charges decreased by $2.6 million per year and profits improved by $390,000 per year. There were not significant differences in complications between control and intervention patients and in no case (95% CI, 0% to 1.6%) did the triage criteria adversely affect quality of care. The early transfer triage criteria may be a safe and efficacious decision aid for improving bed utilization in intermediate and coronary care units. In addition, this study shows the feasibility of and potential benefits from applying practice guidelines at a community hospital.

Improving the outcome and efficiency of intensive care: the impact of an intensivist.

Data from two 3-month time periods before and after the arrival of a pediatric intensivist were collected prospectively and compared to determine the intensivist's impact on ICU mortality, use of monitoring and therapeutic modalities, and efficiency of ICU bed utilization. Severity of illness and care modalities were determined daily for all patients with the Physiologic Stability Index and the Therapeutic Intervention Scoring System. The only major organizational change in the postintensivist period was the organization and implementation of a daytime ICU team. Case mix variables, including sex; medical/surgical, emergency/elective, and diagnostic distributions; and nursing hours/patient day, were equivalent in the pre-intensivist and postintensivist samples. After the intensivist's arrival, there was a significant decrease in admissions with very low severity of illness (Physiologic Stability Index less than 4; 52% vs. 34%; p less than .05) and a significant decrease in bed utilization by patients who received only monitoring services (27% vs. 17% of bed days; p less than .001). The severity of the illness-adjusted ICU mortality rate was significantly higher in the pre-intensivist period than in the postintensivist period (weighted mean mortality difference 5.3 +/- 2.6%; p less than .05). The incidence of both therapeutic and monitoring modalities increased in the postintensivist period. These results indicate that a pediatric intensivist can improve mortality rates and efficiency of bed utilization in the pediatric ICU.

Admissions from surgical waiting lists.

Many factors tend to reduce the efficiency of bed utilization in general hospitals. A numerically small, but clinically well-recognized, cause of wastage arises from the failure of waiting list patients to attend for admission when offered beds. The relative severity of the problem varies between clinical specialties, according to the proportions of total admissions accounted for by waiting list patients. In general medicine, such wastage is small, waiting list admissions being only about 16% of total admissions (Ministry of Health and General Register Office, 1963); in general surgery, gynae cology, and E.N.T. surgery, however, the corres ponding proportions are of the order of 45 %, 62 %, and 84%, respectively, so that the problem is potentially more serious. In a study involving two London hospitals, the reasons given by patients who failed to attend for admission were investigated (Croome, Ingram, and Qvist, 1964). Of 7,119 patients sent for, 1,630 (22-9%) failed to attend; and of the 1,630, 63% gave reasons which Croome et al. considered to be 'irresponsible'. In a more limited study at Mansfield, Ward-McQuaid (1964) reported a non-arrival rate of 25 % among general surgical patients. However, in a subsequent study of male patients undergoing repair of inguinal hernia in the Mansfield hospitals (Morris, Ward, and Handyside, 1968), the non arrival rate encountered was less than 11%. This apparently striking difference in behaviour between two groups drawn from the same population prompted further study of waiting list patients in this area. Method