The need for acute, subacute and nonacute care at 105 general hospital sites in Ontario. Joint Policy and Planning Committee Non-Acute Hospitalization Project Working Group

BACKGROUND

Previous studies of hospital utilization have not taken into account the use of acute care beds for subacute care. The authors determined the proportion of patients who required acute, subacute and nonacute care on admission and during their hospital stay in general hospitals in Ontario. From this analysis, they identified areas where the efficiency of care delivery might be improved.

METHODS

Ninety-eight of 189 acute care hospitals in Ontario, at 105 sites, participated in a review that used explicit criteria for rating acuity developed by Inter-Qual Inc., Marlborough, Mass. The records of 13,242 patients who were discharged over a 9-month period in 1995 after hospital care for 1 of 8 high-volume, high-variability diagnoses or procedures were randomly selected for review. Patients were categorized on the basis of the level of care (acute, subacute or nonacute) they required on admission and during subsequent days of hospital care.

RESULTS

Of all admissions, 62.2% were acute, 19.7% subacute and 18.1% nonacute. The patients most likely to require acute care on admission were those with acute myocardial infarction (96.2% of 1826 patients) or cerebrovascular accident (84.0% of 1596 patients) and those admitted for elective surgery on the day of their procedure (73.4% of 3993 patients). However, 41.1% of patients awaiting hip or knee replacement were admitted the day before surgery so did not require acute care on admission. The proportion of patients who required acute care on admission and during the subsequent hospital stay declined with age; the proportion of patients needing nonacute care did not vary with age. After admission, acute care was needed on 27.5% of subsequent days, subacute care on 40.2% and nonacute care on 32.3%. The need for acute care on admission was a predictor of need for acute care during subsequent hospital stay among patients with medical conditions. The proportion of patients requiring subacute care during the subsequent hospital stay increased with age, decreased with the number of inpatient beds in each hospital and was highest among patients with congestive heart failure, chronic obstructive pulmonary disease and pneumonia.

INTERPRETATION

In 1995, inpatients requiring subacute care accounted for a substantial proportion of nonacute care days in Ontario's general hospitals. These findings suggest a need to evaluate the efficiencies that might be achieved by introducing a subacute category of care into the Canadian health care system. Generally, efforts are needed to reduce the proportion of admissions for nonacute care and of in-hospital days for other than acute care.

Predicting mortality after coronary artery bypass surgery: what do artificial neural networks learn? The Steering Committee of the Cardiac Care Network of Ontario

OBJECTIVE

To compare the abilities of artificial neural network and logistic regression models to predict the risk of in-hospital mortality after coronary artery bypass graft (CABG) surgery.

METHODS

Neural network and logistic regression models were developed using a training set of 4,782 patients undergoing CABG surgery in Ontario, Canada, in 1991, and they were validated in two test sets of 5,309 and 5,517 patients having CABG surgery in 1992 and 1993, respectively.

RESULTS

The probabilities predicted from a fully trained neural network were similar to those of a "saturated" regression model, with both models detecting all possible interactions in the training set and validating poorly in the two test sets. A second neural network was developed by cross-validating a network against a new set of data and terminating network training early to create a more generalizable model. A simple "main effects" regression model without any interaction terms was also developed. Both of these models validated well, with areas under the receiver operating characteristic curves of 0.78 and 0.77 (p > 0.10) in the 1993 test set. The predictions from the two models were very highly correlated (r=0.95).

CONCLUSIONS

Artificial neural networks and logistic regression models learn similar relationships between patient characteristics and mortality after CABG surgery.

Analysis of deaths while waiting for cardiac surgery among 29,293 consecutive patients in Ontario, Canada. The Steering Committee of the Cardiac Care Network of Ontario

OBJECTIVES

To assess death rates among patients waiting for cardiac valve surgery or isolated coronary artery bypass surgery (CABG), and to determine independent risk factors for death while waiting for isolated CABG.

DESIGN

Prospective cohort analysis based on an inclusive registry.

SETTING

Nine cardiac surgical units in Ontario, Canada.

PATIENTS

29,293 consecutive patients scheduled for cardiac surgery between October 1991 and June 1995.

MAIN OUTCOME MEASURES

Death rates while waiting for surgery were determined among patients scheduled for isolated CABG, isolated valve surgery, or combined procedures. Predictors of death among patients with isolated CABG were determined from multivariate analysis.

RESULTS

There were 141 deaths (0.48%) among 29,293 patients. Adjusting for age, sex, and waiting time, patients waiting for valve surgery had a significantly increased risk of death compared with patients waiting for CABG alone (adjusted odds ratio 1.88, 95% confidence interval (CI) 1.23 to 2.88, p = 0.004). Results were similar for patients waiting for combined valve and CABG procedures compared with those who were waiting for isolated CABG. Independent risk factors for death while waiting for isolated CABG included: impaired left ventricular function (odds ratio 2.47, 95% CI 1.59 to 3.84, p < 0.001); advancing age (for each decade, odds ratio 1.41, 95% CI 1.10 to 1.80, p = 0.007); male sex (odds ratio 1.95, 95% CI 1.00 to 3.81, p = 0.05); and waiting longer than the maximum time recommended in Canadian guidelines for a patient's clinical profile (odds ratio 1.59, 95% CI 1.01 to 2.51, p = 0.044). After scaling waiting time to surgery or death continuously in days, the same predictors emerged.

CONCLUSIONS

Patients waiting for valve surgery have a higher risk of death than patients waiting for isolated CABG. Guidelines to promote safer and fairer queuing for non-CABG cardiac surgery are needed. Shorter waiting lists, better compliance with existing guidelines, and guideline revisions to upgrade patients with left ventricular dysfunction could generate additional reductions in the already low risk of death for patients waiting for isolated CABG.

Fifteen-year trends in risk severity and operative mortality in elderly patients undergoing coronary artery bypass graft surgery

BACKGROUND

Trends in risk-severity and operative mortality (OM) were examined in 3330 consecutive patients aged 70 years and older who underwent isolated coronary artery bypass graft surgery (CABG) between 1982 and 1996.

METHODS AND RESULTS

The proportion of elderly patients rose significantly over time (P<.001). Crude OM among the elderly was 7.2% in 1982 to 1986, fell to 4.4% in 1987 to 1991, but did not improve thereafter. Logistic regression analysis of OM was used to construct relative risk groups (low, medium, or high). The prevalence of high-risk elderly patients rose significantly over time (P=.001) from 16.2% in 1982 to 1986 to 19.5% in 1987 to 1991 and 26.9% in 1992 to 1996. OM in high-risk patients fell significantly (P=.044) from 17.2% in 1982 to 1986 to 9.1% in 1987 to 1991 and was 8.9% in 1992 to 1996. Contemporary independent predictors of OM among elderly patients were poor ventricular function (LV grade 2 to 3, odds ratio [OR], 2.6; 95% confidence interval [CI], 1.3 to 5.2; and LV grade 4, OR, 10.7; 95% CI, 4.4 to 26); previous CABG (OR, 3.7; 95% CI, 2.0 to 7.0), female sex (OR, 1.8; 95% CI, 1.1 to 2.8), peripheral vascular disease (OR, 1.8; 95% CI, 1.1 to 2.8), and diabetes (OR, 1.7; 95% CI, 1.1 to 2.7). Previous angioplasty was protective (OR, 0.3; 95% CI, 0.1 to 0.9).

CONCLUSIONS

OM in elderly patients has declined significantly in recent years despite an increase in the prevalence and severity of their risk factors. A careful weighing of risk, rather than advanced age alone, should determine who is offered surgical revascularization. In this regard, poor ventricular function and repeat CABG continue to have the greatest impact on OM in elderly patients.

Self-perceived health status of women three to five years after the diagnosis of gestational diabetes: a survey of cases and matched controls

OBJECTIVE

Our purpose was to determine the long-term effect on self-perceived health status and maternal perceptions of the offspring's health status after women had been labeled with a diagnosis of gestational diabetes.

STUDY DESIGN

We designed a mail survey of women who had participated in a large cohort study 3 to 5 years earlier. A tentative address list was developed for 139 women diagnosed with gestational diabetes and 406 matched controls; 33 and 89 questionnaires, respectively, were returned as "wrong address," but 106 case and 317 control addresses were potentially valid. The primary analysis compared cases and controls on the general health scale of the SF-36. Secondary outcomes included comparisons of the groups' mean results on a worry scale, ratings of the health of the child born in the index pregnancy, disability days, physician visits, diabetes preventive behaviors, and diabetes risk appraisal.

RESULTS

The usable response rates were 65 of 106 (61.3%) and 197 of 317 (62.1%), with no meaningful demographic differences found between respondents and nonrespondents. For general health, the mean score for cases was 68.9 (SD 22.34) vs 73.8 (SD 19.86) for controls, p = 0.05 (prespecified, one-tailed). After factors found to be independently related to health perception (age, race, birth place, and comorbidity) were controlled, the differences narrowed, with a mean score for cases of 70.09 versus 73.38 for controls, p = 0.11, two-tailed. Compared with controls, cases were more worried about their own health (p = 0.02, two-tailed), rated their children as less healthy (p = 0.005, two-tailed), and perceived themselves as more likely to have diabetes (p < 0.0001, two-tailed).

CONCLUSION

The diagnosis of gestational diabetes may lead to long-term changes in how women view their own health status and that of the child born during the affected pregnancy.

In the queue for total joint replacement: patients' perspectives on waiting times. Ontario Hip and Knee Replacement Project Team

We assessed patients on the waiting lists of a purposive sample of orthopaedic surgeons in Ontario, Canada, to determine patients' attitudes towards time waiting for hip or knee replacement. We focused on 148 patients who did not have a definite operative date, obtaining complete information on 124 (84%). Symptom severity was assessed with the Western Ontario/McMaster Osteoarthritis Index and a disease-specific standard gamble was used to elicit patients' overall utility for their arthritic state. Next, in a trade-off task, patients considered a hypothetical choice between a 1-month wait for a surgeon who could provide a 2% risk of post-operative mortality, or a 6-month wait for joint replacement with a 1% risk of post-operative mortality. Waiting times were then shifted systematically until the patient abandoned his/her initial choice, generating a conditional maximal acceptable wait time. Patients were divided in their attitudes, with 57% initially choosing a 6-month wait with a 1% mortality risk. The overall distribution of conditional maximum acceptable wait time scores ranged from 1 to 26 months, with a median of 7 months. Utility values were independently but weakly associated with patients' tolerance of waiting times (adjusted R-square = 0.059, P = 0.004). After splitting the sample along the median into subgroups with a relatively 'low' and 'high' tolerance for waiting, the subgroup with the apparently lower tolerance for waiting reported lower utility scores (z = 2.951; P = 0.004) and shorter times since their surgeon first advised them of the need for surgery (z = 3.014; P = 0.003). These results suggest that, in the establishment and monitoring of a queue management system for quality-of-life-enhancing surgery, patients' own perceptions of their overall symptomatic burden and ability to tolerate delayed relief should be considered along with information derived from clinical judgements and pre-weighted health status instruments.

The HIV-specific advance directive

OBJECTIVE

To determine whether persons living with HIV find a disease-specific advance directive more acceptable than a generic directive.

DESIGN

Randomized clinical trial.

SETTING

HIV consumer organization and hospital-based HIV clinic.

PARTICIPANTS

Volunteer sample of persons with HIV.

INTERVENTIONS

The disease-specific HIV Living Will, the generic Centre for Bioethics Living Will, or both.

MEASUREMENTS AND MAIN RESULTS

Of 101 participants who received both advance directives, 78 (77.2%) preferred the disease-specific HIV Living Will and 23 (22.8%) preferred the generic Centre for Bioethics Living Will (p < .001). Most participants who preferred the HIV Living Will did so because it was more specific or relevant to their situation.

CONCLUSIONS

Persons living with HIV prefer a disease-specific to a generic advance directive. They should be offered a disease-specific advance directive. Our findings should also encourage investigators to develop and evaluate disease-specific advance directives in other clinical settings.

Selective screening for gestational diabetes mellitus. Toronto Trihospital Gestational Diabetes Project Investigators

BACKGROUND

The usual approach to detecting gestational diabetes mellitus is to screen all pregnant women by measuring their plasma glucose after a 50-g oral glucose load at 24 to 28 weeks' gestation. Women are referred for an oral glucose-tolerance test if the plasma glucose concentration one hour later is > or = 140 mg per deciliter (7.8 mmol per liter). We hypothesized that the efficiency of screening could be enhanced by considering women's risks of gestational diabetes on the basis of their clinical characteristics.

METHODS

We studied 3131 pregnant women who underwent both the screening and the diagnostic tests. We randomly selected data on half the women and used them to derive new screening strategies. We categorized each woman's risk of gestational diabetes mellitus on the basis of her age, body-mass index before pregnancy, and race. We developed strategies that entailed no screening for low-risk women, usual care for intermediate-risk women, and universal screening with lower thresholds -- plasma glucose values of 130 mg per deciliter (7.2 mmol per liter) or 128 mg per deciliter (7.1 mmol per liter) -- for high-risk women. The strategies were validated with data on the other half of the women.

RESULTS

The new strategies allowed a 34.6 percent reduction in the number of screening tests performed (95 percent confidence interval, 32.3 to 37.0) and detected 81.2 to 82.6 percent of the women with gestational diabetes as compared with the 78.3 percent detected through usual care. The percentage of false positive screening tests was significantly reduced, from 17.9 percent with usual care to 16.0 per cent (P=0.02) or 15.4 percent (P<0.001) with the new strategies, depending on the threshold values for high-risk women.

CONCLUSIONS

Consideration of women's clinical characteristics allows efficient selective screening for gestational diabetes.

Assessing the outcomes of coronary artery bypass graft surgery: how many risk factors are enough? Steering Committee of the Cardiac Care Network of Ontario

OBJECTIVES

We sought to determine whether more comprehensive risk-adjustment models have a significant impact on hospital risk-adjusted mortality rates after coronary artery bypass graft surgery (CABG) in Ontario, Canada.

BACKGROUND

The Working Group Panel on the Collaborative CABG Database Project has categorized 44 clinical variables into 7 core, 13 level 1 and 24 level 2 variables, to reflect their relative importance in determining short-term mortality after CABG.

METHODS

Using clinical data for all 5,517 patients undergoing isolated CABG in Ontario in 1993, we developed 12 increasingly comprehensive risk-adjustment models using logistic regression analysis of 6 of the Panel's core variables and 6 of the Panel's level 1 variables. We studied how the risk-adjusted mortality rates of the nine cardiac surgery hospitals in Ontario changed as more variables were included in these models.

RESULTS

Incorporating six of the core variables in a risk-adjustment model led to a model with an area under the receiver operating characteristic (ROC) curve of 0.77. The ROC curve area slightly improved to 0.79 with the inclusion of six additional level 1 variables (p = 0.063). Hospital risk-adjusted mortality rates and relative rankings stabilized after adjusting for six core variables. Adding an additional six level 1 variables to a risk-adjustment model had minimal impact on overall results.

CONCLUSIONS

A small number of core variables appear to be sufficient for fairly comparing risk-adjusted mortality rates after CABG across hospitals in Ontario. For efficient interprovider comparisons, risk-adjustment models for CABG could be simplified so that only essential variables are included in these models.

Breast cancer patients' attitudes about rationing postlumpectomy radiation therapy: applicability of trade-off methods to policy-making

PURPOSE

Along with evidence, clinical policies must take patients' values into account. Particularly where evidence is limited and where assumptions of utility-maximizing behavior may not be valid, new methods such as trade-off techniques (TOTs), which allow elicitation of patients' treatment alternatives, might be useful in policy formulation. We used TOTs to assess breast cancer patients' attitudes toward two clinical policies designed to ration adjuvant postlumpectomy breast radiation therapy.

METHODS

Cross-sectional interviews were performed in a tertiary cancer center. A total of 102 patients were presented with information about the side effects and benefits associated with two hypothetical decisions: (1) willingness to receive treatment elsewhere to shorten the wait for radiation therapy, and (2) foregoing radiation therapy in the face of small marginal benefits. For each scenario, a TOT was used to identify the maximal acceptable wait time (MAWT) for therapy and the benefit threshold at which the patient would forego therapy. Associations of clinical and demographic factors with these decisions were determined by regression analysis.

RESULTS

Patients would be willing to wait, on average, 7 weeks before wanting to leave their city for radiation therapy, less than the 13-week delay our patients actually faced. Older patients were less willing to wait (P = .013); 46% of patients would not give up radiation therapy, even in the face of no stated benefit. Willingness to give up radiation therapy was predicted by willingness to accept delay (odds ratio [OR], 1.84; 95% confidence interval [CI], 1.05 to 3.37) and being employed (OR, 2.61; 95% CI, 1.08 to 6.54). Patients with larger tumors were less willing to give up radiation therapy (OR, 0.57; 95% CI, 0.31 to 0.97).

CONCLUSION

Even in difficult decisions such as rationing postlumpectomy breast cancer radiation therapy, TOTs can inform policy formulation by indicating the distributions of patients' preferences.

Distributional dilemmas in health policy: large benefits for a few or smaller benefits for many?

OBJECTIVES

To examine funding priorities assigned by health ministry officials when choosing between clinical programs that offer similar overall benefits distributed in different ways (e.g. large gains for a few versus small gains for many), and to compare the relative magnitude of any distributional bias to age biases.

METHODS

A survey consisting of paired hypothetical health care programs was mailed to the 135 most senior officials of the Health Ministry in Ontario, Canada (population 11.5 million). Respondents were asked to assume they were members of a panel allocating a fixed sum of money to one of two programs in each pair. All program descriptions included the number of persons affected each year by a given disease and the average survival gains from the hypothetical programs. Some scenarios also mentioned the side-effects associated with programs and/or the average age of the beneficiaries.

RESULTS

Four respondents had retired/died. Of 131 eligible respondents, 80/131 (61%) provided usable responses. Asked to choose between providing large benefits to a few citizens and small benefits to a great many, 23% (95% CI: 14%, 33%) of respondents were unable to decide, but 55.8% (95% CI: 47%, 70%) favored providing large benefits to fewer patients. Eliminating the 23% unable to decide, 47/62 or 76% (CI 63%, 86% expressed a distributional preference. With a smaller distributional discrepancy, indecision increased, with 35% of respondents having no preference and the remainder split almost evenly between the two programs. Other scenarios showed that health officials' pro-youth biases were only slightly larger than their distributional preferences and that distributional preferences were magnified when combined with minor differences in average ages of beneficiaries.

CONCLUSIONS

A substantial minority of health care decision-makers had difficulty choosing between programs with similar overall gains and distributional differences--a result consistent with the utilitarian assumptions of cost-effectiveness analysis. However, when distributional differences were large, decision-makers clearly favored large gains for a few beneficiaries rather than small gains for many. Policy analysts should explicitly weigh distributional issues along with aggregate health gains when addressing resources allocation problems.