Large anisotropy in the magnetic susceptibility of metallic carbon nanotubes

Through magnetic linear dichroism spectroscopy, the magnetic susceptibility anisotropy of metallic single-walled carbon nanotubes has been extracted and found to be 2-4 times greater than values for semiconducting nanotubes. This large anisotropy can be understood in terms of large orbital paramagnetism of metallic nanotubes arising from the Aharonov-Bohm-phase-induced gap opening in a parallel field, and our calculations quantitatively reproduce these results. We also compare our values with previous work for semiconducting nanotubes, which confirm that the magnetic susceptibility anisotropy does not increase linearly with the diameter for small-diameter nanotubes.

Patient perceived priorities between technical skills and interpersonal skills: their influence on correlates of patient satisfaction

OBJECTIVES

The study objective was to elucidate the differences in factors related to overall patient satisfaction levels among subgroups based on whether patients placed higher priorities on technical or interpersonal skills of health care personnel.

METHODS

This questionnaire survey targeted 2341 patients discharged from five Japanese hospitals in 2007. Patients were grouped based on whether they prioritized technical or interpersonal skills by chi-squared automatic interaction detection (CHAID) analysis. Multiple regression analysis was used to compare and evaluate differences in various factors related to patient satisfaction among the subgroups.

RESULTS

Survey respondent rate was 55.7% (1305 patients). CHAID analysis showed that patients, in particular those warded in surgery departments, tended to place a higher value on technical skills, although paediatric and rehabilitation patients also placed a high value on interpersonal skills. While it has been shown that non-surgical patients tended to prioritize interpersonal skills, our results revealed that patients warded in the surgery department who did not undergo operations still prioritized technical skills. These variation patterns among patient subgroups were further supported by regression analysis of overall patient satisfaction. In surgical patients, the 40- to 79-year-old subgroup regarded technical skills to be more important and the role of the doctor was found to be more associated with overall satisfaction. However, even among surgical patients, older patients placed higher values on interpersonal skills, and overall satisfaction was found to be more associated with health care professionals (besides doctors) and living arrangements.

CONCLUSIONS

We conclude that differences in patient satisfaction levels could be influenced by different perspectives on prioritized skills.

An outcome prediction model for adult intensive care

OBJECTIVE

To develop a prediction model of 28-day mortality in adult intensive care units using administrative data.

DESIGN, SETTING AND PARTICIPANTS

We obtained data from 33 ICUs in Japan on all adult patients discharged from ICUs in 2007. Three predictive models were developed using (i) the five variables of the Critical Care Outcome Prediction Equation (COPE) model (age, unplanned admission, mechanical ventilation, hospital category and primary diagnosis) (the C model); (ii) 11 variables, including the COPE variables and six additional variables (sex, reason for ICU entry, time between hospital admission and ICU entry, use of fresh frozen plasma or a platelet preparation, dialysis, and use of pressors/vasoconstrictors (the P+ model); and (iii) ten of the 11 variables, excluding primary diagnosis (the P- model). Data for 6758 patients were stratified at the hospital level and randomly divided into test and validation datasets. Using the test dataset, five, 10 or nine variables were subjected to multiple logistic regression analysis (sex was excluded [P > 0.05]).

MAIN OUTCOME MEASURE

Mortality at 28 days after the first ICU day.

RESULTS

Areas under the Receiver Operating Characteristic curve (AUROCs) for the test dataset in the C, P+ and P- models were 0.84, 0.89 and 0.87, respectively. Predicted mortality for the validation dataset gave Hosmer-Lemeshow chi2 values of 12.91 (P = 0.12), 10.76 (P = 0.22) and 13.52 (P = 0.1), respectively, and AUROCs of 0.84, 0.89 and 0.90, respectively.

CONCLUSIONS

Our P- model is robust and does not depend on disease identification. This is an advantage, as errors can arise in coding of primary diagnoses. Our model may facilitate mortality prediction based on administrative data collected on ICU patients.

Primary chemotherapy patterns for ovarian cancer treatment in Japan

AIMS

Evidence-based clinical practices can improve patient outcomes, especially in the area of chemotherapy. In Japan, it is not known how well physicians adhere to evidence-based chemotherapy guidelines. This study aimed to assess physician compliance with national guidelines for ovarian cancer primary chemotherapy in Japan.

METHODS

Using an administrative database, we analyzed 209 cases of surgical laparotomy without neoadjuvant chemotherapy as the primary intervention for adnexal cancer. Cases were identified across seven teaching hospitals between 2003 and 2006.

RESULTS

Of the 136 patients receiving inpatient chemotherapy, 101 cases (74%) were treated with platinum-taxane therapy. In five hospitals, platinum-taxane therapy was used in more than 75% of patients, compared to 56% and 32% in the other two hospitals, respectively. The proportion of patients receiving paclitaxel and carboplatin concomitant therapy (TC therapy) was 67%, although significant variation was noted between hospitals (range 32% to 94%, P < 0.001). Of the 91 patients receiving TC therapy, 59 (65%) were given full-dose monthly regimens, while 32 cases (35%) were treated with divided doses weekly. Weekly TC therapy was more frequently provided in hospitals with a low volume of patients receiving TC therapy. Patients under the age of 65 receiving inpatient chemotherapy were more likely to receive full-dose regimens than patients 65 or older (68% vs 43%, P = 0.005). Publication of national treatment guidelines did not appear to substantially impact chemotherapy practice patterns.

CONCLUSIONS

Adherence to standardized chemotherapy was comparable to rates in European countries, although rates among hospitals differed significantly. Elderly patients were more likely to receive divided-dose regimens.

Risk-adjusted increases in medical resource utilization associated with health care-associated infections in gastrectomy patients

RATIONALE, AIMS AND OBJECTIVES

Quantifying the impact of health care-associated infections (HAIs) on medical resource utilization is necessary for payers and providers to appropriately allocate limited resources for interventions. However, previous studies tend to involve single institutions and do not take into account patient and practice variations between several hospitals. The objective of this study was to conduct a multi-institutional risk-adjusted comparison of HAI-associated impact on medical resources in gastrectomy patients in Japan.

METHODS

Health care-associated infections were identified using a combination of International Classification of Diseases-10 codes and antibiotic utilization patterns in 1058 gastrectomy patients from 10 Japanese hospitals. Multiple linear regression models and risk adjustment were used to analyse the impact of HAIs on: (1) total hospital costs; (2) antibiotic costs; and (3) post-surgical length of stay (LOS).

RESULTS

Overall HAI incidence for the database was 20.3%, with a range of 8.8-29.6% among the 10 hospitals. Regression models showed that HAIs were significantly associated with increases in all three indicators. Risk-adjusted comparisons revealed that HAIs were associated with an increase of US$2767 (range: US$1035-6513) in overall hospital cost, US$202 (US$98.8-764.6) antibiotic costs and 10.6 (4.7-24 days) post-surgical LOS days.

CONCLUSIONS

Even after adjusting for patient characteristics and other variables, there was still a high degree of variation observed in the impact of HAIs on total hospital costs and antibiotic costs from a third-party payer's perspective and post-surgical LOS among the 10 hospitals. This information can increase the efficiency of allocation of resources for interventions to reduce HAIs.

Difference in lifetime medical expenditures between male smokers and non-smokers

OBJECTIVES

It is controversial whether smokers have higher lifetime medical expenditures than non-smokers, because smokers have high annual medical expenditures but comparatively short lives. We examined differences in lifetime medical expenditures between them.

METHODS

We constructed life tables for male smokers and non-smokers from 40 years of age. We calculated average annual medical expenditures of them categorized by survivors and deceased, which were used to examine differences in lifetime medical expenditures between them and perform sensitivity analyses.

RESULTS

Smokers had a higher mortality rate, shorter life expectancy, and generally higher annual medical expenditures than non-smokers. We also observed tendencies for smokers to have higher inpatient expenditures, but non-smokers to have higher outpatient expenditures. Although non-smokers had lower long-term cumulative medical expenditures between 64 and 81 years of age, their lifetime medical expenditures were higher by a minimal amount. Sensitivity analyses did not change this result.

CONCLUSIONS

Smoking may not cause increases in lifetime medical expenditures because smokers had lower lifetime medical expenditures than non-smokers. However, it was clear that smokers, especially survivors, often had higher annual medical expenditures than non-smokers. The importance of tobacco control is still relevant.

Change in clinical practice after publication of guidelines on breast cancer treatment

OBJECTIVE

Several studies raise questions about whether clinical practice guidelines actually guide practice. We evaluated patterns of use of breast-conserving surgery (BCS) over time to examine the effect of guideline publication.

DESIGN

Retrospective analysis of time-series data on breast cancer treatment. Multiple logistic regression analysis was performed, adjusting for covariates including the patient's age, comorbidity status and admission year, to assess whether the use of BCS was higher after publication of treatment guidelines.

SETTING

Five teaching hospitals participating in the Quality Improvement/Indicator Project (QIP) in Japan.

PARTICIPANTS

Female breast cancer patients who received surgical treatment at five teaching hospitals from January 1996 through December 2007 (n = 2199).

MAIN OUTCOME MEASURE

Rates of use of BCS.

RESULTS

The proportion of BCS use increased from 26.4% before guideline publication to 59.9% after guideline publication in Japan. After controlling for other characteristics, the use of BCS has increased significantly over time, especially since 2001. Women aged 70 years and older (P=0.004) and those with any comorbidity (P < 0.001) were significantly less likely to receive BCS.

CONCLUSIONS

This study demonstrated that the adjusted proportion of BCS has increased dramatically since 2001, 2 years after guideline publication in Japan and this is consistent with a relationship between guideline publication and a change in this clinical practice.

Development and analysis of a nationwide cost database of acute-care hospitals in Japan

OBJECTIVES

Understanding of hospital cost is crucial to achieve an ideal balance between the assurance and improvement of patient safety and quality, and efficient use of finite resources. However, neither a standardized calculation methodology nor a large-scale database of costs in acute-care hospitals exists in Japan. This study aims to develop a standardized methodology, construct a nationwide cost database in Japan, analyse the characteristics of the database and examine the relationship between the cost and the charge from the viewpoint of an appropriate reflection of the cost to the price.

METHOD

We designed the costing framework, gathered the data for patients discharged from 139 acute-care hospitals in Japan between July 2004 and October 2004 and constructed a database containing information on 284,730 patients. The characteristics of the database and the relationship between the cost and the charge were investigated.

RESULTS

In the nationwide database we constructed, a wide range in the average cost per hospitalization and average cost per diem was observed. A wide variation of cost components was seen across major diagnostic categories. Moreover, there was a high correlation between the cost and the charge (Correlation coefficient = 0.94).

CONCLUSIONS

After designing a costing framework, a nationwide database comprised of individual case-level costs with components for acute-care hospitals in Japan was successfully developed. We hope this study contributes to appropriate decision making and helps motivate further research geared towards efficient hospital management and a rational payment system in Japan.

Assessment of transparency of cost estimates in economic evaluations of patient safety programmes

OBJECTIVES

Transparency of costing is essential for decision-makers who require information on the efficiency of a health care programme, because effective decisions depend largely on applicability to their settings. The main objectives of this study were to assess published studies for transparency of cost estimates.

METHODS

We first developed criteria with two axes by reviewing publications dealing with economic evaluations and cost accounting studies: clarification of the scope of costing and accuracy of method evaluating costs. We then performed systematic searches of the literature for studies which estimated prevention costs and assessed the transparency and accuracy of costing based on our criteria.

RESULTS

Forty studies met the inclusion criteria. Half of the studies reported data for both the quantity and unit price of programmes in regard to prevention costs. Although 30 studies estimated costs of adverse events, 19 of these described the scope of costing only, and just five studies used a micro-costing method. Among 30 studies that estimated 'gross cost savings' and 'net cost savings', there was a huge discrepancy in labels.

CONCLUSIONS

Even if a cost study was conducted in accordance with existing techniques of economic evaluation which mostly paid attention to internal validity of cost estimates, without adequate explanation of the process of costing, reproducibility cannot be assured and the study may lose its value as scientific information. This study found that there is tremendous room for improvement.

Work stress and workload of full-time anesthesiologists in acute care hospitals in Japan

PURPOSE

The number of anesthesiologists per population in Japan is small compared with that in Europe and North America. While there is a growing concern that hard work causes anesthesiologists' fatigue and may compromise patient safety, the workload and physical stress, as well as the impact of staff support on physicians' stress have not been assessed in detail. The goal of this study was to evaluate the working environment, anesthesia workload, and occupational stress of anesthesiologists in Japan.

METHODS

A questionnaire survey was performed targeting 1010 members of the Japanese Society of Anesthesiologists working as anesthesiologists affiliated with acute care hospitals in Japan. Data on background information, working environment, operation anesthesia duties, and stress were collected, and the relationship of work stress with background, environment, and anesthesia duties was evaluated by linear regression analysis.

RESULTS

Responses were obtained from 383 full-time anesthesiologists (response rate, 43.9%). The total anesthesia time per week was 23.6 h on average. The work stress score was 114.3 +/- 30.2 (mean +/- SD) when the average workers' work stress score in Japan was 100. The work stress score was significantly associated with "years of experience" (with experience < 10 years considered as the reference; 10-19 years: beta = -0.18, P = 0.02, > or = 20 years: beta = -0.15, P = 0.04), "hospital with > or = 500 beds" (with a hospital with < or = 299 beds considered as the reference; beta = 0.15, P = 0.04), "total time of anesthesia per week" (beta = 0.18, P.02), "estimated annual cases managed by an anesthesiologist" (beta = 0.12, P = 0.04) and "no-support stress" (beta = 0.21, P < 0.01) on linear regression analysis (R(2) = 0.12).

CONCLUSION

Our results provide a quantitative assessment of the duties of anesthesiologists and show that work stress among anesthesiologists is related to workload and other factors.

Possible phase transition deep inside the hidden order phase of ultraclean URu2Si2

To elucidate the underlying nature of the hidden order (HO) state in heavy-fermion compound URu(2)Si(2), we measure electrical transport properties of ultraclean crystals in a high field, low temperature regime. Unlike previous studies, the present system with much less impurity scattering resolves a distinct anomaly of the Hall resistivity at H;{*} = 22.5 T, well below the destruction field of the HO phase = or approximately 36 T. In addition, a novel quantum oscillation appears above a magnetic field slightly below H;{*}. These results indicate an abrupt reconstruction of the Fermi surface, which implies a possible phase transition well within the HO phase caused by a band-dependent destruction of the HO parameter.

The subjective incremental cost of informed consent and documentation in hospital care: a multicentre questionnaire survey in Japan

OBJECTIVE

To reveal the amount of time and financial cost required to obtain informed consent and to preserve documentation.

METHODS

The questionnaire was delivered to all staff in six acute care public hospitals in Japan. We examined health care staff perceptions of the time they spent obtaining informed consent and documenting information. All data were collected in 2006 and estimates in the past week in 2006 were compared to estimates of time spent in a week in 1999. We also calculated the economic costs of incremental amounts of time spent in these procedures.

RESULTS

In 2006, health care staff took about 3.89 hours [95% Confidence Interval (CI) 3.71-4.07] per week to obtain informed consent and 6.64 hours (95% CI 6.40-6.88) per week to write documentation on average. Between 1999 and 2006, the average amount of time for conducting informed consent was increased to 0.67 (P < 0.001) hours per person-week, and the average amount of time for documentation was increased to 0.70 (P < 0.001) hours per person-week. The annual economic cost of activities for informed consent and documentation in a 100-bed hospital increased from 117 755 to 449 402 US dollars.

CONCLUSIONS

We found a considerable increase in time spent on informed consent and documentation, and associated cost over a 7-year time period. Although greater attention to the informed consent process should be paid to ensure the notions of patient autonomy and self-determination, the increased resources devoted to these practices must be considered in light of current cost containment policies.

Factors associated with system-level activities for patient safety and infection control

Objective

We examined the relationship between hospital structural characteristics and system-level activities for patient safety and infection control, for use in designing an incentive structure to promote patient safety.

Methods

This study utilized a questionnaire to collect institutional data about hospital infrastructure and volume of patient safety activities from all 1039 teaching hospitals in Japan. The patient safety activities were focused on meetings and conferences, internal audits, staff education and training, incident reporting and infection surveillance. Generalized linear modeling was used.

Results

Of the 1039 hospitals surveyed, 418 (40.2%) hospitals participated. The amount of activities significantly increased by over 30% in hospitals with dedicated patient safety and infection control full-time staff (P < 0.001 and P < 0.01, respectively). High profit margins also predicted the increase of patient safety programs (P < 0.01). Perceived lack of administrative leadership was associated with reduced volume of activities (P < 0.05), and the economic burden of safety programs was found to be disproportionately large for small hospitals (P < 0.05).

Conclusions

Hospitals with increased resources had greater spread of patient safety and infection control activities. To promote patient safety programs in hospitals, it is imperative that policy makers require the assignment of dedicated full-time staff to patient safety. Economic support for hospitals will also be required to assure that safety programs are sustainable.

Economic evaluations of maintaining patient safety systems in teaching hospitals

OBJECTIVE

The aim of this study was to assess the status and the cost of hospital patient safety systems.

METHODS

We conducted a national questionnaire survey of all the 1039 teaching hospitals in Japan. The study was constructed to evaluate the costs of the systems for patient safety focused on staff assignment, meetings and conferences, internal audit, staff education and training, incident reporting, infection surveillance, infectious disposal, management of medication use, clinical engineering, and patient counseling.

RESULTS

The status to maintain patient safety systems might be at least as decent. The mean estimated total cost of systems for patient safety was US$ 20,449 (95% confidence interval [CI], 19,632-21,266) per 100 bed-months or US$ 8.52 (95% CI, 8.18-8.86) per inpatient-day. The ratio of costs to revenue was 1.68% (95% CI, 1.61-1.75). The annual necessary costs occurring in hospitals where the costs of patient safety were under the average level across all the 1032 teaching hospitals in Japan was US$ 259.7 million.

CONCLUSIONS

Our results show that hospital-wide activities for patient safety pose significant costs to hospitals and national healthcare systems. Our data may provide financial information for designing and improving patient safety systems.

Comparisons of risk-adjusted clinical outcomes for patients with aneurysmal subarachnoid haemorrhage across eight teaching hospitals in Japan

OBJECTIVES

To assess predictive value of patient characteristics and severity of aneurysmal subarachnoid haemorrhage (SAH) patients for clinical outcomes, and thereby estimate risk-adjusted clinical outcomes and compare the outcomes across hospitals.

METHODS

We selected 256 aneurysmal SAH patients from eight teaching hospitals in Japan. The clinical outcomes of patients at the time of discharge were assessed by the Glasgow Outcome Scale (GOS). A multiple logistic regression analysis was performed to identify predictors for the GOS status at the time of discharge. The risk-adjusted proportion of patients with a favourable GOS outcome was then estimated for each facility and compared across hospitals.

RESULTS

The logistic regression analysis revealed that younger age (P < 0.001), patients with good World Federations of Neurological Surgeons grade at admission (P < 0.001) and absence of chronic renal failure or ischaemic heart disease as a comorbid condition (P < 0.001) were identified as significant predictors for favourable GOS outcome at the time of discharge among aneurysmal SAH patients (C statistic = 0.88). We found that one hospital had significantly better outcomes than the others.

CONCLUSION

After comparison of risk-adjusted values across hospitals, the clinical management methods of the hospital that showed the best performance were examined and shared among providers.

Cost of open versus laparoscopic appendectomy

AIMS

There are several literatures on outcome variations between patients treated with an open appendectomy (OA) and a laparoscopic appendectomy (LA). However, there are no studies assessing differences in cost and outcome that adjust for age and hospital function or region. This study examines the differences in cost and procedure-related complications of OA and LA procedures.

MATERIALS AND METHODS

This study contains 1703 appendectomy patients treated for appendicitis in 76 academic hospitals and 80 community hospitals. Demographic variables, clinical variables, length of stay (LOS), total charges (TC; US$) and complication rates were analyzed for both OA and LA procedures. The specific contributions of LA to LOS, TC, and complication rate were identified using multivariate analysis.

RESULTS

1469 (86.3%) patients underwent OA and 234 (13.7%) underwent LA. Complicated appendicitis was diagnosed in 13.1% of OA cases and 15.4% of LA cases. The complication rates were 3.4% in OA and 2.6% in LA (p=0.504). There were significant differences in LOS and TC by severity of appendicitis and by procedure type. After risk adjustment for the other study variables, LA was associated with a higher TC than OA ($1458, p0.001). However there were no significant differences in LOS or complication rates between the two treatment groups.

CONCLUSIONS

This study suggests that LA increases cost, but has no significant impact on LOS or complication rates. However, other outcomes such as quality of life or subgroup analysis for obese patients are needed for a more complete economic analysis of OA and LA.

Cost of hospital-wide activities to improve patient safety and infection control: a multi-centre study in Japan

OBJECTIVE

The aim of this study was to assess the financial costs to hospitals for the implementation of hospital-wide patient safety and infection control programs.

METHODS

We conducted questionnaire surveys and structured interviews in seven acute-care teaching hospitals with an established reputation for their efforts towards improving patient safety. We defined the scope of patient safety activities by use of an incremental activity measure between 1999 and 2004. Hospital-wide incremental manpower, material, and financial resources to implement patient safety programs were measured.

RESULTS

The total incremental activities were 19,414-78,540 person-hours per year. The estimated incremental costs of activities for patient safety and infection control were calculated as US$ 1.100-2.335 million per year, equivalent to the employment of 17-40 full-time healthcare staff. The ratio of estimated costs to total medical revenue ranged from 0.55% to 2.57%. Smaller hospitals tend to shoulder a higher burden compared to larger hospitals.

CONCLUSIONS

Our study provides a framework for measuring hospital-wide activities for patient safety. Study findings suggest that the total amount of resources is so great that cost-effective and evidence-based health policy is needed to assure the sustainability of hospital safety programs.

Impact of hospital accreditation on infection control programs in teaching hospitals in Japan

BACKGROUND

In Japan, hospital infection control (IC) programs are frequently under-resourced, whereas their improvement is considered a pressing issue. Hospital accreditation may have a positive impact on IC program performance. The Japan Council for Quality Health Care (JCQHC) is a hospital accreditation organization that now prescribes broad elements of IC as part of its accreditation standards.

METHODS

We sent questionnaire surveys to all teaching hospitals in Japan to characterize the current situation of hospital IC activities and identify the impact of accreditation on IC infrastructure and performance. The self-administered questionnaire that we used was developed based on the JCQHC accreditation standards. Surveys were sent to all institutions in 2004 and again in 2005.

RESULTS

Of the 638 hospitals surveyed, 335 (52%) answered in both years. Most IC practitioners in Japanese teaching hospitals were working part time and spent limited hours performing IC duties. Surveillance was poorly implemented in Japan, and IC activities without evidence of effectiveness were widely performed. Surveillance was implemented more frequently in hospitals with adequate IC staffing. Improvement in IC infrastructure and performance between the surveys was larger in the newly accredited hospitals than the others.

CONCLUSIONS

Hospital accreditation had a significant impact on hospitals' IC infrastructure and performance.

Impact of age and procedure on resource use for patients with ischemic heart disease

OBJECTIVES

Impact of age on healthcare expenditures should be assessed by targeting on specific diseases and controlling for procedures and severity of illness. Relationship between age and resource use in patients receiving acute care medicine for ischemic heart disease (IHD) was examined.

METHODS

We analyzed 19,874 IHD patients treated in 82 academic and 92 community hospitals. Length of stay (LOS), total charges (TC), and high outliers of LOS and TC were analyzed for every age group (under 65 years, 65-74 years, 75 years or older). Independent effects of age on LOS, TC, and high outliers of LOS and TC were determined using multivariate analysis.

RESULTS

7863 (39.6%) patients were under 65 years, 7181 (36.1%) between 65 years and 74 years, and 4830 (24.3%) aged 75 years or older. Proportion of angina or non-medical treatment was significantly different among three age categories (angina 72%, 75%, 71.4%; non-medical 37.3%, 40.9%, 38.9%, respectively). Significant association with LOS or TC was identified in patients receiving coronary artery bypass graft surgery with percutaneous intracoronary intervention, who were most associated with TC high outlier.

CONCLUSIONS

Age had a modest impact on resource use, as compared with procedures. Policy makers need to acknowledge the impact of procedures on healthcare spending.

The effect of age and procedure on resource use for patients with cerebrovascular disease

Objective

Many studies have described the impact of population ageing on health care expenditures, but few have assessed its impact on specific diseases adjusted for severity and procedure. This study examined the relationship between an ageing population and resource use in patients with cerebrovascular disease (CVD).

Methods

A total of 13,856 CVD patients were treated in 82 academic and 92 community hospitals. Demographic variables, clinical variables, length of stay (LOS) and total charges were analysed by age group (under 65 years, 65-74 years and 75 years or older). The independent effects of age on LOS and total charge were determined using multivariate analysis.

Results

There were 5172 (37%) patients under 65 years of age, 4096 (30%) 65-74 years and 4588 (33%) 75 years or older. Intracranial infarction or ischaemia was diagnosed in 69% of the patients, haemorrhage in 23% and subarachnoid haemorrhage in 9%. The overall mortality was 6% (5% in under 65 years, 5% in 65-74 years and 9% in 75 years or older; P < 0.001). There were significant differences in the proportion of procedures performed in each age category. Age and procedure were significantly associated with LOS, particularly the latter. Age had no significant association with total charge, but procedure was highly associated.

Conclusions

Ageing has no significant impact on total charge. Instead policy-makers should acknowledge the effect of procedures on health care costs, conduct economic evaluations and monitor use of procedures.

Measuring hospital-wide activity volume for patient safety and infection control: a multi-centre study in Japan

Background

In Japan, as in many other countries, several quality and safety assurance measures have been implemented since the 1990's. This has occurred in spite of cost containment efforts. Although government and hospital decision-makers demand comprehensive analysis of these activities at the hospital-wide level, there have been few studies that actually quantify them. Therefore, the aims of this study were to measure hospital-wide activities for patient safety and infection control through a systematic framework, and to identify the incremental volume of these activities implemented over the last five years.

Methods

Using the conceptual framework of incremental activity corresponding to incremental cost, we defined the scope of patient safety and infection control activities. We then drafted a questionnaire to analyze these realms. After implementing the questionnaire, we conducted several in-person interviews with managers and other staff in charge of patient safety and infection control in seven acute care teaching hospitals in Japan.

Results

At most hospitals, nurses and clerical employees acted as the main figures in patient safety practices. The annual amount of activity ranged from 14,557 to 72,996 person-hours (per 100 beds: 6,240; per 100 staff: 3,323) across participant hospitals. Pharmacists performed more incremental activities than their proportional share. With respect to infection control activities, the annual volume ranged from 3,015 to 12,196 person-hours (per 100 beds: 1,141; per 100 staff: 613). For infection control, medical doctors and nurses tended to perform somewhat more of the duties relative to their share.

Conclusion

We developed a systematic framework to quantify hospital-wide activities for patient safety and infection control. We also assessed the incremental volume of these activities in Japanese hospitals under the reimbursement containment policy. Government and hospital decision makers can benefit from this type of analytic framework and its empirical findings.

Meta-analysis comparing clinical effectiveness of drug-eluting stents, bare metal stents and coronary artery bypass surgery

Objective  To compare clinical outcomes among patients receiving drug-eluting stents, bare metal stents, or coronary artery bypass grafting surgery (CABG) to treat coronary artery disease. Data sources  Randomised controlled trials were systematically selected from electronic database for head-to-head comparisons. The results from these head-to-head comparisons were used for an adjusted indirect comparison. Methods  Published randomised controlled trials were reviewed for outcome data in patients treated for coronary artery disease with drug-eluting stents, bare metal stents, or CABG. Head-to-head comparisons were conducted for drug-eluting stents versus bare metal stents and for CABG versus bare metal stents. Adjusted indirect comparison was used to compare drug-eluting stents and CABG. Mid-term clinical outcomes (range: 6-12 months) were investigated and included rates of mortality, myocardial infarction, thrombosis, target lesion revascularisation, target vessel revascularisation, restenosis and major adverse cardiac events. Results  Systematic literature search identified 23 randomised controlled trials (15 for drug-eluting stents vs. bare metal stents, 8 for CABG vs. bare metal stents). Head-to-head comparisons for both single and multiple vessel disease demonstrated that compared with bare metal stents, drug-eluting stents had better outcomes for target lesion revascularisation, target vessel revascularisation, restenosis and major adverse cardiac events. Except target lesion revascularisation, data were similarly favourable for CABG when compared with bare metal stents. Adjusted indirect comparison between drug-eluting stents and CABG in single vessel disease failed to detect significant differences in any of the measured outcomes. Multiple vessel disease data analysis demonstrated that target vessel revascularisation (odds ratio 3.41 [95% CI 2.29-5.08]) and major adverse cardiac events (1.89 [1.28-2.79]) were superior to drug-eluting stents in patients undergoing CABG. Conclusions  Drug-eluting stents and CABG were superior to bare metal stents in terms of target lesion revascularisation (drug-eluting stents only), target vessel revascularisation, restenosis and major adverse cardiac events. There was no difference in clinical outcomes when comparing CABG and drug-eluting stents in patients with single vessel disease, and CABG may be superior to drug-eluting stents for target vessel revascularisation and major adverse cardiac events in patients with multiple vessel disease. However, results may vary between subpopulations with different clinical or socioeconomic differences.

Lag time in an incident reporting system at a university hospital in Japan

BACKGROUND

Delays and underreporting limit the success of hospital incident reporting systems, but little is known about the causes or implications of delayed reporting.

SETTING AND METHODS

The authors examined 6880 incident reports filed by physicians and nurses for three years at a national university hospital in Japan and evaluated the lag time between each incident and the submission of a report.

RESULTS

Although physicians and nurses reported nearly equal numbers of events resulting in major injury (32 v 31), physicians reported far fewer minor incidents (430 v 6387) and far fewer incidents overall (462 v 6418). In univariate analyses, lag time was significantly longer for physicians than nurses (3.79 v 2.20 days; p<0.001). In multivariate analysis, physicians had adjusted reporting lag time 75% longer than nurses (p<0.001) and lag time for major injuries was 18% shorter than for minor injuries (p = 0.011). Adjusted lag time in 2002 and 2004 were 34% longer than in 2003 (p<0.001).

CONCLUSIONS

Physicians report fewer incidents than nurses and take longer to report them. Quantitative evaluation of lag time may facilitate improvements in incident reporting systems by distinguishing institutional obstacles to physician reporting from physicians' lesser willingness to report.

Functional mapping of hospitals by diagnosis-dominant case-mix analysis

BACKGROUND

Principles and methods for the allocation of healthcare resources among healthcare providers have long been health policy research issues in many countries. Healthcare reforms including the development of a new case-mix system, Diagnosis Procedure Combination (DPC), and the introduction of a DPC-based payment system are currently underway in Japan, and a methodology for adequately assessing the functions of healthcare providers is needed to determine healthcare resource allocations.

METHODS

By two-dimensional mapping of the rarity and complexity of diagnoses for patients receiving treatment, we were able to quantitatively demonstrate differences in the functions of different healthcare service provider groups.

RESULTS

On average, inpatients had diseases that were 3.6-times rarer than those seen in outpatients, while major teaching hospitals treated inpatients with diseases 3.0-times rarer on average than those seen at small hospitals.

CONCLUSION

We created and evaluated a new indicator for DPC, the diagnosis-dominant case-mix system developed in Japan, whereby the system was used to assess the functions of healthcare service providers. The results suggest that it is possible to apply the case-mix system to the integrated evaluation of outpatient and inpatient healthcare services and to the appropriate allocation of healthcare resources among health service providers.

Risk adjusted resource utilization for AMI patients treated in Japanese hospitals

Though risk adjustment is necessary in order to make equitable comparisons of resource utilization in the treatment of acute myocardial infarction patients, there is little in the literature that can be practically applied without access to clinical records or specialized registries. The aim of this study is to show that effective models of resource utilization can be developed based on administrative data, and to demonstrate a practical application of the same models by comparing the risk-adjusted performance of the hospitals in our dataset. The study sample included 1748 AMI cases discharged from 10 large, private teaching hospitals in Japan, between 10 April 2001 and 30 June 2004. Explanatory variables included procedures (CABG and PCI), length of stay, outcome, patient demographics, diagnosis and comorbidity status. Multiple linear regression models constructed for the study were able to account for 66.5, 27.7, and 58.4% of observed variation in total charges, length of stay and charges per day, respectively. The performance of models constructed for this study was comparable to or better than performance reported by other studies that made use of explanatory variables extracted from clinical data. The use of administrative data in risk adjustment makes broad scale application of risk adjustment feasible.

Profiling of resource use variation among six diseases treated at 82 Japanese special functioning hospitals, based on administrative data

BACKGROUND

Profiling treatment in Japanese hospitals has rarely been conducted systematically with an administrative database. The study aims to present descriptive statistics of medical profiling and to examine the sources of variation in resource used for six common diseases.

METHODS

Administrative records for 266,677 patients were analyzed to examine variation in length of stay (LOS) and total charge (TC) by hierarchical multiple linear regression for cases of ischemic stroke, ischemic heart disease (IHD), great vessel disease (GVD), respiratory neoplasm, gastric neoplasm and colonic neoplasm.

RESULTS

Average LOS and TC increased with disease severity and invasiveness of surgical procedure. The coefficient of determination of the full model was highest for LOS in IHD (0.432), and for TC that was highest in GVD (0.702). Among various variable sets examined, surgical procedures explained largest variance in resource use.

CONCLUSION

With a standardized database derived from claims data, wide audience of stakeholders in Japanese healthcare will be able to access the profiling of practice or disease variation concerned.

Why are physicians not persuaded by scientific evidence? A grounded theory interview study

Background

The government-led "evidence-based guidelines for cataract treatment" labelled pirenoxine and glutathione eye drops, which have been regarded as the standard care for cataracts in Japan, as lacking evidence of effectiveness, causing great upset among ophthalmologists and professional ophthalmology societies. This study investigated the reasons why such "scientific evidence of treatment effectiveness" is not easily accepted by physicians, and thus, why they do not change their clinical practices to reflect such evidence.

Methods

We conducted a qualitative study based on grounded theory to explore physicians' awareness of "scientific evidence" and evidence-supported treatment in relation to pirenoxine and glutathione eye drops, and to identify current barriers to the implementation of evidence-based policies in clinical practice. Interviews were conducted with 35 ophthalmologists and 3 general practitioners on their prescribing behaviours, perceptions of eye drop effectiveness, attitudes toward the eye drop guideline recommendations, and their perceptions of "scientific evidence."

Results

Although few physicians believed that eye drops are remarkably effective, the majority of participants reported that they prescribed eye drops to patients who asked for them, and that such patients accounted for a considerable proportion of those with cataracts. Physicians seldom attempted to explain to patients the limitations of effectiveness or to encourage them to stop taking the eye drops. Physicians also acknowledged the benefits of prescribing such drugs, which ultimately outweighed any uncertainty of their effectiveness. These benefits included economic incentives and a desire to be appreciated by patients. Changes in clinical practice were considered to bring little benefit to physicians or patients. Government approval, rarity of side effects, and low cost of the drops also encouraged prescription.

Conclusion

Physicians occasionally provide treatment without expecting remarkable therapeutic effectiveness, as exemplified by the use of eye drops. This finding highlights that scientific evidence alone cannot easily change physicians' clinical practices, unless evidence-based practices are accepted by the general public and supported by health policy.

Quality and productive efficiency in simple laceration treatment

OBJECTIVES

The surgical management and outcome of outpatient care for patients with simple lacerations were compared across three institutions. We examined the variations in wound infection rate, total charge and medical resource use in terms of prophylactic antibiotic prescription, frequency of outpatient visits and required days for stitch removal.

DESIGN

Retrospective and consecutive chart review.

STUDY PARTICIPANTS

Patients receiving treatment for simple lacerations in the outpatient departments of three institutions in Japan between June 2000 and August 2001. OUTCOME MEASURES AND METHOD: The basic patient characteristics, treatment method for the laceration and incidence of wound infection were collected. Variations in the wound infection rate were examined across the institutions. We then examined the variations in the medical resource use and total charge for patients without wound infection among the institutions by multiple linear regression model.

RESULTS

A total of 479 patients were reviewed. The proportion of patients with blunt injury, patients with simple lacerations to the head or face, and those with underlying medical disease were significantly different among the three institutions. The wound infection rate did not significantly differ (1.9% in Institution A, 1.3% in B, 3.0% in C, P = 0.555). The medical resource use for patients without wound infection was significantly different and small in Institution A.

CONCLUSION

We identified variations in the resource use for completing wound care among three institutions, whereas the wound infection rate revealed no significant difference among the institutions. There existed some room for improvement in the productive efficiency of simple laceration treatment.

Impact of treatment policies on patient outcomes and resource utilization in acute cholecystitis in Japanese hospitals

Background

Although currently available evidence predominantly recommends early laparoscopic cholecystectomy (LC) for the treatment of acute cholecystitis, this strategy has not been widely adopted in Japan. Herein, we describe a hospital-based study of patients with acute cholecystitis in 9 Japanese teaching hospitals in order to evaluate the impact of different institutional strategies in treating acute cholecystitis on overall patient outcomes and medical resource utilization.

Methods

From an administrative database and chart review, we identified 228 patients diagnosed with acute cholecystitis who underwent cholecystectomy between April 2001 and June 2003. In order to examine the relationship between hospitals' propensity to perform LC and patient outcomes and/or medical resource utilization, we divided the hospitals into three groups according to the observed to expected ratio of performing LC (LC propensity), and compared the postoperative complication rate, length of hospitalization (LOS), and medical charges.

Results

No hospital adopted the policy of early surgery, and the mean overall LOS among the subjects was 30.9 days. The use of laparoscopic surgery varied widely across the hospitals; the adjusted rates of LC to total cholecystectomies ranged from 9.5% to 77%. Although intra-operative complication rate was significantly higher among patients whom LC was initially attempted when compared to those whom OC was initially attempted (9.7% vs. 0%), there was no significant association between LC propensity and postoperative complication rates. Although the postoperative time to oral intake and postoperative LOS was significantly shorter in hospitals with high use of LC, the overall LOS did not differ among hospital groups with different LC propensities. Medical charges were not associated with LC propensity.

Conclusion

Under the prevailing policy of delayed surgery, in terms of the postoperative complication rate and medical resource utilization, our study did not show the superiority of LC in treating acute cholecystitis patients. The timing of surgery and discharge was mainly determined by the institutional policy in Japan, rather than by the clinical course of the patient; however, considering the substantially less postoperative pain and shorter recovery time of LC compared to OC, LC should be actively applied for the treatment of acute cholecystitis. If the policy of early surgery were universally applied, the advantage of LC over OC may be more clearly demonstrated.

Self-rated health and social role as predictors for 6-year total mortality among a non-disabled older Japanese population

We examined whether social role and self-rated health in an older population were predictors for 6-year total mortality among a non-disabled community-dwelling older population in Saku City, Nagano Prefecture, Japan, surveyed in 1992 and 1998. A total of 8090 men and women aged 65-99 years who reported no disability in performing activities of daily living (ADL) at the time of the survey in 1992 and provided information on their survival status at follow-up 6 years later were analyzed in this study. One dependent variable was survival status in 1998 and independent variables were various factors potentially associated with total mortality, which were obtained from a questionnaire survey at the baseline. During the 6-year interval, having poor self-rated health and poor social roles were identified as significant predictors for total mortality among both men and women. This study revealed that social role and self-rated health are independent predictors for 6-year total mortality for non-disabled Japanese aged 65 years or older.

Inequity in the price of physician activity across surgical procedures

OBJECTIVES

A rational payment system is being sought in Japanese health care-one that accurately reflects the required time and the level of technical difficulty when valuing physician activity. The objective of this study is to examine the current surgical payment system in Japan by clarifying the hourly values allocated to physician activity.

METHODS

This study focused on the 22 surgical procedures most frequently registered in our study database of administrative data gathered from 11 teaching hospitals in Japan. The current fee-for-service reimbursement system does not formally define which cost components surgical fees cover. It was therefore necessary for us to examine directly each reimbursement item to determine which component it represented. Next we examined the current system from the following viewpoints: (1) variation in the hourly values allocated to physician activity, for an individual surgeon or a surgical team, among types of surgery by using the actual data; (2) the association between the hourly values and the operation time or the level of technical difficulty.

RESULTS

The hourly values allocated to physician activity were low (US dollars 61.0 and 121.5 per surgeon: means of case 1 and case 2 estimations). The hourly values varied inequitably among types of surgery (from US dollars -28 to 237 and from US dollars 6 to 328: ranges in the case 1 and case 2 estimations). When long surgeries were excluded, shorter surgeries tended to have higher hourly values. The association between the hourly values and the difficulty level was less clear and their variation was large even at the same difficulty level.

CONCLUSION

In the current payment system, the surgical fee is deemed to include fee for physician activity as well as materials, equipment and so on. To develop a rational payment system, first, the scope of the surgical fee and that of the physician activity fee should be separated and clearly defined. Second, the latter should be modeled to reflect the manpower volume and the level of technical difficulty needed for each surgical procedure. Third, fees should be set by utilizing the cost estimates with empirical data.

Effects of cognitive function on functional decline among community-dwelling non-disabled older Japanese

This study examined whether cognitive impairment, falls, and urinary incontinence (UI) were independent predictors of functional decline using a 2-year observation of a non-disabled older Japanese cohort living in a community from 1999 to 2001. A total of 139 men and 214 women aged 70-94 years at the baseline who were independent in both activities of daily living (ADL) and instrumental activities of daily living (IADL) were analyzed in this study. Independent variables, such as cognitive impairment, falls, UI, and other possible factors associated with functional decline were obtained from an interview survey at the baseline. A dependent variable was functional status in ADL and IADL obtained at the time of the 2-year follow-up. During the 2-year follow-up, cognitive function was a significant predictor for both IADL dependence and ADL and/or IADL dependence. Using a group of subjects with Mini Mental State Examination (MMSE) scores of 30-27 points as a reference group, a significant correlation was identified between lower MMSE scores and an increased odds ratio for functional decline. Lower cognitive function was a significant predictor of functional decline, even among those older Japanese whose cognitive function was deemed to be within the normal range.

Determinants of the diffusion of computed tomography and magnetic resonance imaging

OBJECTIVES

The aim of this study is to explain factors influential to the diffusion of computed tomography (CTs) and magnetic resonance imaging (MRIs).

METHODS

Variables were identified from a review of the literature on the diffusion of health technologies. A formal process was applied to build a conceptual model of the mechanism that drives technology diffusion. Variables for the analysis were classified as predisposing, enabling, or reinforcing factors, in keeping with a model commonly used to explain the diffusion of health behaviors. Multiple regression analysis was conducted using year 2000 OECD data.

RESULTS

The results of this study showed that total health expenditure per capita (p < .01, both CTs and MRIs) and flexible payment methods to hospitals (p < .05, both CTs and MRIs) were significantly associated with the diffusion of CTs and MRIs (adjusted R2 = 0.477, 0.656, respectively).

CONCLUSIONS

This study presents a systematically developed model of the mechanism governing technology diffusion. Important findings from the study show that purchasing power, represented by total health expenditure per capita and economic incentives to hospitals in the form of flexible payment methods, were positively correlated with diffusion. Another important achievement of our model is that it accounts for all thirty OECD member countries without excluding any as outliers. This study shows that variation across countries in the diffusion of medical technology can be explained well by a logical model with multiple variables, the results of which hold profound implications for health policy regarding the adoption of innovations.

Profiling Hospital Performance of Laparoscopic Cholecystectomy Based on the Administrative Data of Four Teaching Hospitals in Japan

Over the last decade in Japan, laparoscopic cholecystectomy (LC) has replaced traditional open cholecystectomy as the standard of elective surgery for cholelithiasis. The laparoscopic approach has a clinical course relatively easier to standardize among the different types of intraabdominal surgery. However, significant practice variation is suspected in Japan, but there has been little demonstration or discussion based on empirical data. Through the analysis of 1589 elective LC cases from four leading teaching hospitals in Japan between 1996 and 2000, this study aims to demonstrate the surgical variations and to investigate their determinants regarding the length of hospital stay and the health care charge. Substantially and significantly large variation existed among the hospitals in terms of the length of hospital stay and the total health care charge, even after the differences in patient factors were adjusted. Particularly, the combined drug and exam charge per day was strikingly different among the four hospitals, which indicated that the daily process also varied widely, as did the total course of inpatient care. In addition, intra-hospital variation was also remained very large even after adjusting for all the potential correlates studied. This study alarmingly points out great room for improvement in the efficiency of health care resource use and potentially in the quality of care through standardization of LC. It has serious implications for the national policy and individual providers under the on-going health care reforms directed toward higher efficiency and quality.

The effect of aging on functional decline among older Japanese living in a community: a 5-year longitudinal data analysis

BACKGROUND AND AIMS

Using longitudinal data analyses, we examined the effects of aging on functional decline, based on activities of daily living (ADL) and instrumental activities of daily living (IADL) during a 5-year follow-up among older people living in a community in Japan.

METHODS

The baseline survey in July 1988 involved all elderly residents aged 60 or older in Saku City, Nagano, Japan (N=13418). All survivors of this cohort were asked to participate in follow-up surveys conducted in 1989, 1990, 1991, 1992 and 1993. Five items of ADL and five of IADL were measured on each survey. A generalized estimating equations (GEE) analysis was used to examine the effects of aging on the increase of the proportion of subjects with functional dependence.

RESULTS

These results indicated that the proportion of subjects who were dependent in ADL increased during the 5-year period by 2.2 times (p<0.001) and the proportion of those who were dependent in either ADL or IADL increased during the same period by 1.8 times (p<0.001). Gender did not appear to be significantly associated with functional decline.

CONCLUSIONS

The GEE analysis in this study identified the statistically significant effect of aging on the increase of the proportion of subjects with functional dependence based on ADL and IADL.

Practice variation in perioperative antibiotic use in Japan

OBJECTIVE

Under the fee-for-service system, the overuse and misuse of perioperative antibiotics have become serious concerns in Japan. The objective of the present study is to investigate practice variations of perioperative antimicrobial prophylaxis between and within hospitals, and to identify any opportunities for improvement.

METHODS

We polled 319 surgeons in six specialties employed by 11 teaching hospitals in Japan. We developed questionnaires with vignettes, asking physicians about their practice of antimicrobial prophylaxis in six surgical procedures (gastrectomy, hysterectomy, cataract surgery, clipping of cerebral aneurysm, hip fracture surgery, and coronary artery bypass graft) and utilization of institutional clinical pathways.

RESULTS

Average durations of prophylaxis varied by procedure, from 1.6 days for cataract surgery to 5.8 days for clipping surgery. Variation was also observed between institutions for the same procedure, e.g. institutional averages for the duration of prophylaxis for gastrectomy ranged from 2.3 to 7 days. Large intra-institutional variation in prophylaxis duration and inconsistent use of clinical pathways were observed in the cases of gastrectomy, hip fracture surgery, and clipping surgery. At one hospital, 20% of physicians performing gastrectomy indicated the use of an institutional clinical pathway, and prophylaxis duration ranged from 3 to 6 days. For cataract surgery and hysterectomy, clinical pathways were universally applied and intra-institutional practice variation was small, yet prophylaxis duration varied widely between hospitals and third-generation cephalosporins were used extensively. Average length of prophylaxis for hysterectomy ranged from 1.8 to 6 days and 43% of respondents prescribed third-generation cephalosporins.

CONCLUSIONS

In Japan, perioperative antimicrobial prophylaxis lacks standardization. Efforts to strengthen an evidence-based approach to antimicrobial prophylaxis need to be made a priority at both the national and institutional levels.

[Surgeons' fees--What they should be?]

Changes in medical technology and economic conditions in Japan require that we reexamine the allocation of medical resources and the structure of surgeon's fees. A new payment system based on Diagnosis Procedure Combination (DPC) and an associated cost accounting system went in to use in 2001. Through quantitative analysis and critique of data gathered by these new systems, it might be possible to establish fair surgeons' fees and to improve the efficiency of the medical care delivery system. For its social responsibility and autonomy, the profession of medicine should take an active leadership role in current health care reforms.

Estimation of the impact of providing outpatients with information about SARS infection control on their intention of outpatient visit

To examine the effect of provision of information about the infection control in the specific infection disease treatment unit in a city hospital on the outpatient’s intention of outpatient service use, respondents who underwent outpatient medical care at the hospital (N = 821) were asked whether or not they intended to continue the outpatient visit at the hospital if a severe acute respiratory syndrome (SARS) patient was admitted to the unit. Although 56% of respondents replied that they could continue to visit the department if a SARS patient was admitted to the unit in the hospital before they read the information, the proportion of those who intended to continue outpatient care significantly increased by 15% after they read it. The logistic regression analyses revealed that respondents who had frequently visited the outpatient department (P < 0.001), those who felt relieved by reading the information about the unit (P < 0.001), and those who did not worry about nosocomial SARS infection inside the hospital (P < 0.001) were significantly more likely to reply that they would continue outpatient visits. We estimated that admission of a SARS patient to the unit would result in a 20% decrease in the cumulative total number of outpatients in the hospital during a 180-day interval after admission of a SARS patient to the unit, and the cumulative total number of outpatients increased by 7% after they read the information. This study suggests that providing outpatients with appropriate information about SARS infection control in the hospital had a statistically significant and substantial impact on the outpatients’ intention to continue outpatient visits at the hospital.

Association of hospital resource use with comorbidity status and patient age among hip fracture patients in Japan

OBJECTIVES

This study examined the association of resource use with comorbidity status and patient age among hip fracture patients who underwent surgical treatment.

DESIGN

We used a database from the Voluntary Hospitals of Japan Quality Indicator Project that involved 10 privately owned leading teaching hospitals in Japan.

SETTING

Four of these hospitals in Japan.

PARTICIPANTS

We selected 778 operable hip fracture patients aged 65 or older who were admitted to these hospitals between January 1996 and August 2000 (mean age: 80.3 +/- 7.3 years).

MEASUREMENTS

A linear mixed model was performed to identify factors associated with the resource use, such as total length of stay (LOS), LOS before surgery, LOS after surgery, total hospital charges, charges for diagnostic examinations, charges for surgery, and length of theater time, among operable hip fracture patients.

RESULTS

The mean LOS was 45.9 days, and the mean total hospital charges were US dollars 14,495.0. Results from linear mixed models revealed that higher age was significantly associated with shorter length of theater time (P < 0.01), and that the presence of comorbidity among hip fracture patients was significantly associated with longer total LOS (P < 0.01), longer LOS after surgery (P < 0.001), higher charges for diagnostic examinations (P < 0.001), and shorter length of theater time (P < 0.01).

CONCLUSION

These results suggest that the presence of comorbidity among operable hip fracture patients requires greater resource use during their hospital stay, but higher age is not significantly associated with greater resource use at all.