Powerful Predictor Of Mortality Research Articles

Role of Adipose Tissue in Determining Muscle Mass in Patients With Chronic Kidney Disease

Malnutrition is a powerful predictor of mortality in chronic kidney disease (CKD). However, its etiology is unclear. We hypothesized that the adipocyte-derived proteins leptin and adiponectin, inflammation (as measured by C-reactive protein, CRP), and insulin resistance (as measured by homeostasis model assessment, HOMA), implicated in the malnutrition-inflammation complex syndrome commonly seen in maintenance dialysis patients, would be associated with the loss of muscle mass in earlier stages of CKD. Arm muscle area was used as an indicator of muscle mass. The Modification of Diet in Renal Disease Study cohort of people with CKD stages 3 and 4 was used for analysis (N = 780). Regression models were carried out to examine the relationships of leptin, adiponectin, CRP, and HOMA with arm muscle area (the main study outcome). Arm muscle area was 39 +/- 15 cm(2) (mean +/- SD), and adiponectin levels were 13 +/- 7 microg/mL. Median and interquartile range (IQR) concentrations were: 9.0 (13.6) ng/mL for leptin, 2.3 (4.9) mg/L for CRP, and 2.4 (2.0) for HOMA. Higher leptin (beta coefficient and 95% confidence interval, -6.9 [-8.7 to -5.1], P < .001) and higher CRP (beta coefficient and 95% confidence interval, -2.7 [-3.9 to -1.4], P < .001) were associated with lower arm muscle area. There was a trend toward lower arm muscle area with higher adiponectin (P = .07), but no association with HOMA (P = .80). Leptin and CRP were associated with lower muscle mass in subjects with CKD at stages 3 and 4. Further studies are needed to understand the mechanisms underlying these associations, and to develop targeted interventions for this patient population.

Prognostic importance of plasma NT‐pro BNP in chronic heart failure in patients treated with a β‐blocker: Results from the Carvedilol Or Metoprolol European Trial (COMET) trial

Plasma levels of N-terminal pro-brain natriuretic peptide (NT-pro BNP) are increased in patients with chronic heart failure (CHF). Beta-blockers (BB) may influence these levels but it is unclear whether changes in NT-pro BNP reflect concomitant changes in prognosis. To assess the prognostic importance of NT-pro BNP at baseline and during follow-up, in patients in whom beta-blocker therapy is initiated. In COMET, 3029 patients with CHF in NYHA class II-IV and EF<35% were randomised to carvedilol or metoprolol tartrate and were followed for an average of 58 months. Blood samples were collected for the measurement of NT-pro BNP at baseline (n=1559) and during follow-up (n=309). Baseline plasma concentrations of NT-pro BNP above the median (1242 pg/ml) were associated with higher all-cause mortality (RR 2.77; 95% CI 2.33-3.3, p<0.001). Patients who achieved NT-pro BNP levels<400 pg/ml during follow-up had a lower subsequent mortality (RR 0.32; 95% CI 0.15-0.69, p=0.004). The plasma concentration of NT-pro BNP is a powerful predictor of mortality in patients with CHF. Patients who achieve an NT-pro BNP of <400 pg/ml subsequent to treatment with a beta-blocker have a favourable prognosis.

Prognostic value of the New York Heart Association classification in end-stage renal disease

The New York Heart Association (NYHA) classification is a strong predictor of mortality and an established instrument for risk stratification in patients with heart disease but data on the validity of this classification in end-stage renal disease (ESRD) are sparse. In this study, we tested the predictive value of the NYHA in patients with ESRD and compared it with that of two established indexes of disease severity, i.e. the Khan index and the renal disease severity score (RDSS). The study cohort was composed of 1322 incident patients in a dialysis registry (772 male and 550 female, age 61+/-16 years). During the follow-up period (41+/-27 months) 551 patients died. A multivariate COX model including the NYHA classification explained 39% of the variation in mortality, a figure almost identical to that of a model based on the RDSS (37%) and superior (P<0.001) to that provided by the Khan index-based model (32%). The area under the receiver operating characteristic curve of NYHA classification, as related to all-cause mortality, was 0.74 (95% CI: 0.71-0.77, P<0.001). Again, RDSS had a predictive value for mortality (0.74, 95% CI: 0.72-0.77) identical to that of NYHA and higher than that of the Khan index (0.70, 95% CI: 0.67-0.72). The NYHA is a powerful predictor of mortality in ESRD and provides prognostic information equal or superior to that given by other established indexes of disease severity. Given the pervasive nature of cardiovascular disease in ESRD, this classification may be recommended for risk stratification in this population.

Prehospital hypotension that persists on arrival at the emergency department is a powerful predictor of mortality following major trauma

Prehospital hypotension that persists on arrival at the emergency department is a powerful predictor of mortality following major trauma

Mechanical Dyssynchrony Assessed by Tissue Doppler Imaging Is a Powerful Predictor of Mortality in Congestive Heart Failure With Normal QRS Duration

Mechanical Dyssynchrony Assessed by Tissue Doppler Imaging Is a Powerful Predictor of Mortality in Congestive Heart Failure With Normal QRS Duration

Determinants of Serum Albumin Concentration Analyzed in a Large Cohort of Patients on Maintenance Hemodialysis

Serum albumin concentration is a powerful predictor of mortality in patients on chronic hemodialysis (CHD). This study sought to investigate variables associated with serum albumin concentration. Cross-sectional study in prevalent chronic hemodialysis patients treated at the Renal Research Institute between July 1, 2005 and October 31, 2005. A total of 4,798 (2,199 females) patients were studied. Univariate and multivariate relationships of serum albumin concentration with age, sex, race (black, white, other), vascular access type (arteriovenous fistula/graft, catheter), white blood cells, neutrophils, lymphocytes, equilibrated normalized protein catabolic rate (enPCR), dialysis efficacy (eKdrt/V), hemoglobin, phosphate, bio-intact parathyroid hormone [bioPTH], creatinine, alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Age, access type, and variables of 3 domains, namely, nutrition (enPCR; creatinine), eKdrt/V, and inflammation (white blood cells; neutrophil:lymphocyte ratio; hemoglobin), were related to serum albumin. It is interesting to note that AST was the strongest negative predictor of albumin levels. In CHD patients, serum albumin concentration is defined by a complex interaction of inflammation, nutrition, and dialysis efficacy. The relationship between AST and albumin deserves additional study.

Does Rhythm Matter? The Prognostic Importance of Atrial Fibrillation in Heart Failure

Atrial fibrillation (AF) and congestive heart failure (HF) often coexist, but there is conflicting data regarding the association of AF with outcome in HF. To examine this further we have evaluated the prognostic effect of AF in two complementary CHF populations; a population based data set of 55,106 patients admitted to hospital with CHF, and a cohort of 197 patients recruited after a hospital admission with HF into a management clinical trial. Firstly, data for all hospital admissions in New Zealand from 1988 to 1997 were obtained. Using coding data, 55,106 first admissions for HF were identified, the presence of AF was determined by secondary diagnosis coding, and all cause mortality was obtained. Secondly, patients enrolled in the Auckland Heart Failure Management Study were evaluated for the presence or absence of AF, and for all cause mortality at three years. Mortality at 30 days, 6 and 12 months was significantly lower for AF patients compared to sinus rhythm (SR) in the national admissions cohort. In the clinical trial cohort the presence of AF was also associated with lower three-year mortality, although this difference was not seen when the groups were stratified by Doppler mitral filling pattern (a restrictive filling pattern was associated with reduced longevity compared to SR, non-restrictive or AF). This data shows that the presence of AF in two general HF populations in New Zealand is not associated with an adverse prognosis. HF severity, and in particular a restrictive filling pattern, remain powerful predictors of mortality.

Right bundle branch block and long‐term mortality in patients with acute congestive heart failure

Risk stratification in acute congestive heart failure (ACHF) is poorly defined. The aim of the present study was to assess the impact of right bundle brunch block (RBBB) on long-term mortality in patients presenting with ACHF. The initial 12-lead electrocardiogram was analysed for RBBB in 192 consecutive patients presenting with ACHF to the emergency department. The primary endpoint was all-cause mortality during 720-day follow-up. This study included an elderly cohort (mean age 74 years) of ACHF patients. RBBB was present in 27 patients (14%). Age, sex, B-type natriuretic peptide levels and initial management were similar in patients with RBBB when compared with patients without RBBB. However, patients with RBBB more often had pulmonary comorbidity. A total of 84 patients died during follow-up. Kaplan-Meier analysis revealed that mortality at 720 days was significantly higher in patients with RBBB when compared with patients without RBBB (63% vs. 39%, P = 0.004). In Cox proportional hazard analysis, RBBB was associated with a two-fold increase in mortality (hazard ratio 2.18, 95% CI 1.26-3.66; P = 0.003). This association persisted after adjustment for age and comorbidity. RBBB is a powerful predictor of mortality in patients with ACHF. Early identification of this high-risk group may help to offer tailored treatment in order to improve outcome.

Long-term effects of cardiac rehabilitation on end-exercise heart rate recovery after myocardial infarction

Heart rate recovery (HRR) is a marker of vagal tone that is a powerful predictor of mortality in patients with coronary artery disease. This study aims at evaluating the effects of long-term exercise training on HRR after acute myocardial infarction (AMI), in order to clarify whether prolonged exercise training could maintain a long-term improvement of HRR. Forty-four patients after AMI were enrolled in a 3-month hospital-based exercise training programme. At the end, patients were subdivided into two groups: group A (n=22), patients discharged with a specific home-based exercise training programme and instructions for improving leisure-time physical activity; group B (n=22), patients discharged with generic instructions to maintain physical activity. All patients underwent a cardiopulmonary exercise test before, at the end of 3 months exercise training and at 6 months follow-up. At the end of the hospital-based exercise training programme we observed an increase in peak oxygen consumption [VO2peak; from 13.9+/-3.6 to 18+/-2.7 ml/kg per min (A) and from 14.1+/-3.9 to 17.9+/-2.1 ml/kg per min (B), P<0.001] and in HRR [from 17.1+/-1.8 to 23.4+/-1.4 beats/min (A), and from 18.8+/-2.1 to 24.3+/-1.9 beats/min (B), P<0.001]. At 6 months' follow-up we observed a further improvement in VO2peak (from 18.0+/-2.7 to 20.3+/-2.7 ml/kg per min, P<0.001) and in HRR (from 23.4+/-1.4 to 27.8+/-2.1 beats/min, P<0.001) in group A, but a significant decrease in VO2peak and in HRR in group B (P<0.001). Long-term exercise training is useful for maintaining or improving the beneficial results of the standard 3-month exercise training programme on cardiovascular capacity and HRR. This observation may bear beneficial prognostic effects on patients after AMI.

Heart rate turbulence and heart rate variability in patients with mitral valve prolapse

Heart rate turbulence (HRT) and heart rate variability (HRV) have been shown to be independent and powerful predictors of mortality in a specific group of cardiac patients. However, the predictive values of HRV alone is modest and information on HRV in patients with mitral valve prolapse (MVP) has so far been conflicting. In addition, no studies have previously evaluated HRT in patients with MVP. To define better the effects of MVP on cardiac autonomic function, we assessed HRT and time-domain parameters of HRV in patients with MVP. Fifty patients with MVP and 70 controls without MVP were investigated. The diagnosis of MVP was confirmed by cross-sectional echocardiography in the parasternal long-axis view and apical 4-chamber view. The HRV and turbulence analysis were assessed from a 24-hour Holter recording. When HRT parameters were compared, the values of the HRT onset and slope were significantly lower in MVP patients than in the controls group (-0.109+/-0.207 vs. -0.289+/-0.170%, P=0.001 and 8.6+/-7.2 vs. 11.5+/-7.4 ms/RRI, P=0.043, respectively) and the number of patients who had abnormal HRT onset was significantly higher in the MVP group than in controls (15 vs. 8, P=0.011). In addition, HRV parameters were not statistically different between the two groups. Although we found that the decrease in HRV parameters was not significantly different between MVP patients and controls, HRT variables (especially HRT onset) were significantly lower in MVP patients. Therefore, in our opinion, HRT is an attractive, easily applicable, and better way of non-invasive risk prediction compared with another non-invasive risk predictor, HRV.

Exercise-Based Cardiac Rehabilitation Improves Heart Rate Recovery in Elderly Patients After Acute Myocardial Infarction

Heart rate recovery (HRR), defined as the fall in HR during the first minute after exercise, is a marker of vagal tone, which is a powerful predictor of mortality in patients with coronary artery disease and in older patients. Whether exercise training (ET) modifies HRR in elderly patients recovering from acute myocardial infarction (AMI) is still unknown. Therefore, this study aims at evaluating the effect of ET on HRR in elderly AMI patients. This was a prospective observational study including 268 older patients after AMI (217 men, 51 women), subdivided in two groups: Group A (n = 104), enrolled in an ET program; Group B (n = 164), discharged with generic instructions to continue physical activity. At baseline and at 3-month follow-up, all Group A and 54/164 Group B patients underwent a cardiopulmonary exercise stress test, whereas 110/164 Group B patients underwent an exercise stress test. After completion of the ET program, in Group A we observed an improvement in oxygen consumption at peak exercise (VO2peak; from 14.7 +/- 1.3 to 17.6 +/- 1.9 mL/kg/min, p < .001), in the rate of increase of ventilation per unit of increase of carbon dioxide production (VE/VCO2slope; from 34.2 +/- 3.8 to 30.4 +/- 3.0, p < .001), and in HRR (from 13.5 +/- 3.7 to 18.7 +/- 3.5 beats/min, p < .001). The changes in VO2peak and in VE/VCO2slope after ET were correlated with the improvement of HRR (r = -0.865, p < .01; r = -0.594, p < .01, respectively). No changes in these parameters were observed in Group B patients. In older AMI patients, ET results in HRR improvement, which was correlated to the improvement in cardiopulmonary parameters. These findings may shed additional light on the possible mechanisms of the beneficial prognostic effects of ET in this patient population.

Does the Aristotle Score predict outcome in congenital heart surgery?☆

The Aristotle Score has been proposed as a measure of 'complexity' in congenital heart surgery, and a tool for comparing performance amongst different centres. To date, however, it remains unvalidated. We examined whether the Basic Aristotle Score was a useful predictor of mortality following open-heart surgery, and compared it to the Risk Adjustment in Congenital Heart Surgery (RACHS-1) system. We also examined the ability of the Aristotle Score to measure performance. The Basic Aristotle Score and RACHS-1 risk categories were assigned retrospectively to 1085 operations involving cardiopulmonary bypass in children less than 18 years of age. Multiple logistic regression analysis was used to determine the significance of the Aristotle Score and RACHS-1 category as independent predictors of in-hospital mortality. Operative performance was calculated using the Aristotle equation: performance = complexity x survival. Multiple logistic regression identified RACHS-1 category to be a powerful predictor of mortality (Wald 17.7, p < 0.0001), whereas Aristotle Score was only weakly associated with mortality (Wald 4.8, p = 0.03). Age at operation and bypass time were also highly significant predictors of postoperative death (Wald 13.7 and 33.8, respectively, p < 0.0001 for both). Operative performance was measured at 7.52 units. The Basic Aristotle Score was only weakly associated with postoperative mortality in this series. Operative performance appeared to be inflated by the fact that the overall complexity of cases was relatively high in this series. An alternative equation (performance = complexity/mortality) is proposed as a fairer and more logical method of risk-adjustment.

Deceleration capacity of heart rate as a predictor of mortality after myocardial infarction: cohort study

Decreased vagal activity after myocardial infarction results in reduced heart-rate variability and increased risk of death. To distinguish between vagal and sympathetic factors that affect heart-rate variability, we used a signal-processing algorithm to separately characterise deceleration and acceleration of heart rate. We postulated that diminished deceleration-related modulation of heart rate is an important prognostic marker. Our prospective hypotheses were that deceleration capacity is a better predictor of risk than left-ventricular ejection fraction (LVEF) and standard deviation of normal-to-normal intervals (SDNN). We quantified heart rate deceleration capacity by assessing 24-h Holter recordings from a post-infarction cohort in Munich (n=1455). We blindly validated the prognostic power of deceleration capacity in post-infarction populations in London, UK (n=656), and Oulu, Finland (n=600). We tested our hypotheses by assessment of the area under the receiver-operator characteristics curve (AUC). During a median follow-up of 24 months, 70 people died in the Munich cohort and 66 in the London cohort. The Oulu cohort was followed-up for 38 months and 77 people died. In the London cohort, mean AUC of deceleration capacity was 0.80 (SD 0.03) compared with 0.67 (0.04) for LVEF and 0.69 (0.04) for SDNN. In the Oulu cohort, mean AUC of deceleration capacity was 0.74 (0.03) compared with 0.60 (0.04) for LVEF and 0.64 (0.03) for SDNN (p<0.0001 for all comparisons). Stratification by dichotomised deceleration capacity was especially powerful in patients with preserved LVEF (p<0.0001 in all cohorts). Impaired heart rate deceleration capacity is a powerful predictor of mortality after myocardial infarction and is more accurate than LVEF and the conventional measures of heart-rate variability.

Mechanical Dyssynchrony Assessed by Tissue Doppler Imaging Is a Powerful Predictor of Mortality in Congestive Heart Failure With Normal QRS Duration

We sought to test whether the mechanical dyssynchrony assessed by tissue Doppler imaging (TDI) is a predictor of cardiac events in patients with congestive heart failure (CHF) and QRS duration < or =120 ms. The prevalence and prognostic value of mechanical dyssynchrony in patients with CHF and normal QRS duration have not been well clarified. A total of 106 patients (age 63 +/- 11 years) with CHF and ejection fraction (EF) <35% were followed serially; TDI was performed using four basal and four mid-left ventricular segments to assess the time to peak systolic point from R-wave on electrocardiogram (Ts). The standard deviation of Ts (Ts-SD) and the maximal temporal difference of Ts (Ts-diff) of eight segments were used as an indicator of mechanical dyssynchrony. Clinical events included readmission due to worsening of CHF, cardiac transplantation, and death. After 17 +/- 11 months of follow-up, the clinical event rate was 33% including all-cause mortality of 19%. Prolonged Ts-SD (>37 ms) and Ts-diff (>91 ms) were associated with a significant increase in all clinical events. By multivariate analysis, Ts-diff (>91 ms) was an independent risk factor of clinical events and mortality regardless of age, EF, QRS duration, and use of beta-blocking agents. Mean event-free survival was 16.3 months (95% confidence interval [CI] 11.9 to 20.7) in patients with Ts-diff >91 ms and 31.6 months (95% CI 28.0 to 35.1) in those with Ts-diff < or =91 ms, respectively (p < 0.001). Myocardial dyssynchrony assessed by TDI is a powerful predictor of clinical events in CHF with normal QRS.

Predictors of revascularization method and long-term outcome of percutaneous coronary intervention or repeat coronary bypass surgery in patients with multivessel coronary disease and previous coronary bypass surgery

The optimal revascularization strategy in patients with symptomatic multivessel coronary artery disease (CAD) and previous coronary artery bypass grafting (CABG) remains unknown. We evaluated all patients with previous CABG undergoing isolated, non-emergency multivessel revascularization between 1 January 1995 and 31 December 2000. The analysis concentrated on the independent predictors of the revascularization method, as well as on long-term mortality and its predictors, after calculating a propensity score for the method of revascularization. There were 2191 patients (1487 with reoperation and 704 with percutaneous coronary intervention, PCI) in the study. The most important factors in choosing reoperation were presence of more diseased or occluded grafts, previous infarction, lower ejection fraction (EF), longer interval from first CABG, and more total occlusions of native arteries, as well as absence of a patent mammary graft. The distribution of the propensity score was skewed towards the two extremes. At 5 years, the unadjusted cumulative survival was 79.5% for CABG and 75.3% for PCI, P=0.008. After adjustment for the propensity score for PCI vs. CABG, PCI was associated with a hazard ratio of 1.47 (0.94-2.28), P=0.09. The most powerful predictors of mortality were higher age and lower EF. The choice of the revascularization method in patients with previous CABG is dictated mostly by anatomical considerations and less by clinical characteristics. In contrast, clinical characteristics predominantly affect long-term outcome, whereas the method of revascularization has a limited effect. A randomized clinical trial addressing this important segment of the population with ischaemic heart disease is warranted.

Letter Regarding Article by O’Neill et al, “Peak Oxygen Consumption as a Predictor of Death in Patients With Heart Failure Receiving β-Blockers”

To the Editor: A recent article1 published in Circulation investigated cardiopulmonary exercise testing with a primary aim of comparing patients who were or were not taking β-blockers at the time of the exercise test. The authors’ limitations did not mention the tracking of medication profiles during follow-up. It is likely, especially at a tertiary care center and during the early β-blocker era, that patients who were assigned to the no-β-blocker group at the time of testing were prescribed β-blockers shortly thereafter. There are plenty of data that show that ventilatory efficiency measurement is a more powerful mortality predictor than peak oxygen consumption, and these measures must be explored further.2,3 Data suggest that the peak value of Ve/Vco2 for ventilatory efficiency is probably not the best choice. The …

Prognostic impact of demographic factors and clinical features on the mode of death in high-risk patients after myocardial infarction - A combined analysis from multicenter trials

Contemporary information is lacking on the effect of demographic features and clinical features on the specific mode of mortality after myocardial infarction (MI) in the thrombolytic era. The aims of this study were (1) to examine the risk and trend of a different mode of mortality (i.e., all-cause, arrhythmic, and nonarrhythmic cardiac mortality) in high-risk patients post MI with reduced left ventricular ejection fraction (LVEF) or ventricular arrhythmias; and (2) to assess the predictive value of demographic and clinical variables in the prediction of specific modes of death in high-risk patients post MI in the thrombolytic era. In all, 3,431 patients receiving placebo (2,700 men, median age 64 +/- 11 years) from the EMIAT, CAMIAT, SWORD, TRACE, and DIAMOND-MI studies, with LVEF < 40% or ventricular arrhythmia were pooled. Risk factors for mortality among patients surviving > or = 45 days after MI up to 2 years were examined using Cox regression. Short-term survival (from onset of MI to Day 44 after MI) was also examined for TRACE and DIAMOND-MI, in which patients were recruited within 2 weeks of MI. After adjustment for treatment and study effects, age, previous MI/angina, increased heart rate, and higher New York Heart Association functional class increased the risk of all-cause, arrhythmic, and cardiac mortality. Male gender, history of hypertension, low baseline systolic blood pressure, and Q wave were predictive of all-cause and arrhythmic mortality, whereas diabetes was only predictive of all-cause mortality. Smoking habit and atrial fibrillation had no prognostic value. Similar parameters were also predictive of short-term mortality, but not identical. Our study has shown that in high-risk patients post MI, who have been preselected using LVEF or frequent ventricular premature beats, demographic and clinical features are powerful predictors of mortality in the thrombolytic era. We propose that demographic and clinical factors should be considered when designing risk stratification or survival studies, or when identifying high-risk patients for prophylactic implantable cardiodefibrillator therapy.

Predictive power of ejection fraction and renal failure in patients admitted for chest pain without ST elevation in the troponin era

Ejection fraction (EF) and renal failure (RF) are powerful predictors of mortality in patients with myocardial infarction (MI). There are limited data assessing the predictive value of EF and RF compared with clinical variables in patients without ST elevation using troponin as the diagnostic MI criteria. Consecutive patients admitted from the emergency department underwent serial assessment of cardiac markers, including troponin I. Abnormal EF was defined as < 50%; RF, as creatinine clearance (CrCl) < 60 mL/min. Multivariate analysis was used to compare clinical variables, CrCl, and EF for predicting short- and long-term outcomes. A total of 3074 patients had EF assessed. Mild to moderately reduced EF and CrCl were present in 639 (21%) and 582 (19%) patients, with 403 (13%) and 233 (7.6%) having severe systolic dysfunction and severe RF, respectively. Abnormal EF and RF were both present in 13% of patients (1-year mortality 26%), whereas 52% had both normal EF and CrCl (1-year mortality 3.2%). The presence of either systolic dysfunction or RF increased mortality 3- to 4-fold compared with patients without either. The most important multivariate predictors of 1-year mortality were EF (OR 2.6 [95% CI 1.7-3.8, P < .0001]) and CrCl (OR 2.8 [95% CI 1.8-4.2, P < .0001]). Both RF and EF are strong predictors of cardiac mortality in patients admitted for exclusion of MI. Prediction models that do not include these 2 variables will underestimate risk.

Capturing the full measure of patient outcome improvement using a self‐assessed health adjustment

Self-assessed health (SAH) status is a very simple four-, or five-category self-reported measure of health status that has been shown to be a powerful predictor of mortality, service use and total cost of medical care treatment. It is therefore reasonable to suggest that pre-intervention SAH may influence the extent to which patient outcomes improve following surgery. Using the four-category measure of SAH of Excellent; Good; Fair; Poor, we developed an adjustment factor based on the mean improvement of the SAH category relative to the mean improvement of the overall sample. The results clearly indicate that the higher patients rated their pre-operative health, the greater their pre-post-operative improvement. Adjusting the outcome improvement by this SAH factor provides for the adjustment of the overall sample results by extent to which each category of SAH contributes to the overall mean. The results indicate that by adjusting patient outcome improvement measures by a factor based on pre-intervention SAH, overall sample patient outcome improvement increased 5.8%. The results also indicate that failure to adjust for pre-intervention SAH will result in an understatement of patient outcome improvement following surgery.

Using Self-assessed Health to Predict Patient Outcomes after Total Knee Replacement

Self-assessed health status has been shown to be a powerful predictor of mortality, service use, and total cost of medical care treatment. We investigated the potential for self-assessed health to further serve as a predictor of improvement in health status after a clinical intervention. Using the five-category measure of self-assessed health (excellent, very good, good, fair, or poor), we examined patients' improvements in health status after total knee arthroplasty in each of the WOMAC-defined categories for health status in patients. The results indicate that the greater patients rated their preoperative health, the greater their postoperative improvement. The results suggest that a simple process of asking patients to rate their own health in a presurgery clinic could be a powerful tool in predicting patient outcome. This also suggests that by stratifying preoperative self-assessed health, potential improvements in health status will be more fully captured.