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At least 19 recordsLinked to original sources
PubMed1979

Determinants of survival after Kasai's operation for biliary atresia using actuarial analysis.

Survival after Kasai's operation for "noncorrectable" biliary atresia is influenced by (1) age, (2) large bile ducts, and (3) concentration of the bile bilirubin. Critical values are: age less than 10.5 wk, any evidence of a large bile duct, and a bile bilirubin concentration greater than 8.8 mg/100 ml. Using these 3 factors, a predictive model is able to identify a favorable group with an 89% expected 4 yr survival.

Actuarial Analysis↗
PubMed1979

Comparative method for actuarial analysis of cardiac valve replacements.

The use of survival analysis in cardiac surgical reports has been widely accepted in order to characterise and compare performances of different valve prostheses. However, the analyses that have been described elsewhere may be improved in several respects. The original method proposed for prosthetic valve evalation examined follow-up related to patients rather than the valves themselves and therefore neglected the possibility of factors other than the valve itself which could affect the fate of cardiac patients. Furthermore, there has not yet been any application of life table methods to compare two different sets of data, or to estimate the average time before an event occurs. The present work defines valve function and malfunction and separates patient survival from valve performance. We define statistical indices, namely the median remaining lifetime and the instantaneous decrement rate. Both indices can be useful; the former measures the average survival time and the latter focuses attention on the intensity of risk changes. Using established statistical theory we calculate the significance level of difference between two independent survival rates. We qualify the presentation of probabilities with a statement of the associated standard errors.

Actuarial Analysis↗
PubMed1977

Prognosis of patients after open mitral commissurotomy. Actuarial analysis of late results in 100 patients.

The continuing controversy between proponents of open and closed commissurotomy might be clarified by analysis of late follow-up with modern actuarial techniques that provide a true perspective of patient risk. We have used open mitral commissurotomy exclusively for 15 years in 100 patients. There was one operative death from pancreatitis and one late death from cancer; the actuarially projected survival rate (+/- the standard error) at 10 years is 97 per cent (+/- 2). Thirteen patients had preoperative emboli, 6 of whom were in sinus rhythm and 7 in atrial fibrillation. Two patients had postoperative emboli, both in sinus rhythm. The actuarial chance of remaining free of embolism at 10 years is 97 per cent (+/- 2). Sixteen patients required reoperation on the mitral valve for functional deterioration. The remaining survivors were in Class I or II when last seen. The actuarial chance of not requiring a reoperation after 5 years is 91 per cent (+/- 4) and at 10 years, 38 per cent(+/- 16). Results in different centers are difficult to compare for many reasons, but imprecise statistical methods further obscure such comparisons. The use of actuarial techniques may help to define the role of open mitral commissurotomy.

Adult↗
PubMed1977

Actuarial analysis of surgical results: rationale and method.

The use of time-related methods of statistical analysis is essential for valid evaluation of the long-term results of a surgical procedure. Accurate comparison of two procedures or two prosthetic devices is possible only when the length of follow-up is properly accounted for. The purpose of this report is to make the technical aspects of the acturial, or life table, method easily accessible to the surgeon, with emphasis on the motivation for and the rationale behind it. This topic is illustrated in terms of heart valve prostheses, a field that is rapidly developing. Both the authors and readers of articles must be aware that controversies surrounding the relative merits of various prosthetic designs or operative procedures can be settled only if proper time-related methods of analysis are utilized.

Follow-Up Studies↗
PubMed1978

Carotid and vertebral-basilar transient ischemic attacks: effect of anticoagulants, hypertension, and cardiac disorders on survival and stroke occurrence--a population study.

A population of 199 patients from Rochester, MN, was followed from the time of their first carotid or vertebral-basilar transient ischemic attack (TIA). Patients treated with anticoagulants had no significant difference in survival from untreated patients. Among patients with carotid TIA who received anticoagulants, the net probability of stroke was slightly but not significantly lower than in untreated patients. The difference favoring treated patients with vertebral-basilar TIA was significant starting at three months. The rate of intracranial hemorrhage was higher higher among all patients receiving anticoagulant treatment than among untreated patients and was significantly higher among those 55 to 74 years old. Almost all the hemorrhages occurred after a year or more of anticoagulant treatment and in patients more than 65 years old. Patients with high diastolic blood pressure had a significantly higher net probability of stroke than did patients with lower blood pressure and those receiving antihypertensive drugs. By implication, treatment of hypertension was effective in preventing stroke in patients with TIA. Linear discriminant analysis and actuarial analysis indicated that diastolic blood pressure and anticoagulant therapy were the only factors that influenced stroke occurrence. There was no suggestion that previous myocardial infarction, angina pectoris, valvular heart disease, cardiac arrhythmia, or congestive heart failure--individually or in combination--influenced the occurrence of stroke or survival.

Adult↗
PubMed1992

The prognostic value of the pathological response to combination chemotherapy before cystectomy in patients with invasive bladder cancer. European Organization for Research on Treatment of Cancer--Genitourinary Group.

The prognostic value of the pathological response to combination chemotherapy of deeply invasive transitional cell cancer of the bladder was retrospectively assessed in 147 patients. Data were collected from 8 different centers. Patients were eligible if they had received intravenous combination chemotherapy followed by partial, total or radical cystectomy, and if they had a minimum followup of 2 years after the start of chemotherapy. Of the patients 90% received methotrexate, vinblastine, doxorubicin and cisplatin (M-VAC) or cisplatin plus methotrexate for a median of 3 courses (range 1 to 6). Of the 83 patients who were alive at analysis actuarial median followup was 30.5 months (range 13.2 to 85.6 months). A major pathological response (stage P0, Pis, Pa or P1) was achieved in 41.5% of the patients. Patients with a major pathological response (p stage less than 2) had a 5-year survival of 75% in contrast to 20% for the remaining nonresponding patients (p stage 2 or more). The survival of patients with a major pathological response was independent of whether the response was induced by 2 or more courses of chemotherapy, or whether it was induced by M-VAC in comparison with cisplatin plus methotrexate. Preoperative clinical assessments can identify nonresponding patients correctly and in these cases alternative treatment programs are required, since 80% will die of the disease. Moreover, if neoadjuvant chemotherapy is proved to increase survival, the data emphasize the importance of the response rate of the primary tumor and the need to investigate the optimal number of courses to induce the best response, preferably in the individual patient.

Actuarial Analysis↗
PubMed1977

Long-term experience with porcine aortic valve xenografts.

Between 1971 and 1975, glutaraldehyde-preserved porcine aortic valve xenografts were employed for isolated replacement of the mitral valve (MVR) in 243 patients, replacement of the aortic valve (AVR) in 167 patients, and double valve replacement (AVR and MVR) in 51 patients. Postoperatively, long-term anticoagulation was not routinely given. Operative mortality rates for AVR, MVR, and double valve groups were 7.8, 6.0, and 11.8 per cent, respectively; the majority of early postoperative deaths were associated with concomitant coronary artery disease. No death was attributable to xenograft dysfunction. Follow-up of all patients was obtained. The total duration of follow-up for the MVR group was 347 patient-years, for the AVR GROUP 148 148 patient-years, and for double valve replacement 37 patient-years; maximum follow-up for these three groups was 4.4, 4.0, and 2.4 years, respectively. Actuarial analysis of postoperative survival rates at a common interval of 3 years showed 78 per cent for MVR patients, 91 per cent for AVR patients, and 80 per cent (projected) for patients with double valve replacement (85, 96, and 91 per cent for operative survivors, respectively. At this same interval 92 per cent of MVR patients, 99 per cent of AVR patients, and 93 per cent (projected) of patients with double valve replacement were free of thromboembolic episodes. Altogether, 12 of the total 512 valves implanted exhibited some evidence of dysfunction during the entire period of follow-up evaluation, but in only 2 instances (both mitral) was intrinsic pathological involvement of the xenograft tissue documented. Actuarial analysis of xenograft dysfunction at a common interval of 3 years after operation showed 95 per cent of MVR patients, 98 per cent of AVR patients, and 97 per cent (projected) of patients with double valve replacement to be free of this complication. These data support the use of glutaraldehyde-preserved porcine xenografts as superior bioprostheses that pose a low risk of thromboembolism without anticoagulation. The over-all durability of such valves, within the restriction of a maximum current follow-up interval of 4.4 years, appears comparable to that of currently available mechanical prostheses and justifies continued clinical use.

Animals↗
PubMed1977

Late results with synthetic valved external conduits from venous ventricle to pulmonary arteries.

Eighty-five patients operated on before January 1976 have survived at least 30 days after insertion of a valved external conduit by the venous ventricle (usually the right) and the pulmonary arteries as a part of the repair of their congenital heart disease. Follow-up information is available on 83 patients, and mean follow-up time has been 27.7 months. Seven patients have required reoperation because of obstructive complications. Actuarial analysis indicates that the proportion of patients requiring reoperation is 4.0 +/- 2.8% at 2 years, 12.9 +/- 5.5% at 3 1/2 years, and 30.4 +/- 12.1% at 5 years. In five patients compression of the conduit between the sternum and heart was the primary cause of the obstruction. The proportion requiring reoperation for conduit compression is 2.0 +/- 2.0% at 2 years, 8.6 +/- 4.9% at 3 1/2 years, and 27 +/- 12.4% at 5 years. Age at operation is not related to the proportion of patients requiring reoperation, nor is the type of conduit. No patients have yet required reoperation for conduit compression whose operation has been done since we began systematically to position the conduit well away from the sternum. By actuarial analysis the proportion of patients surviving 5 years is 76.7%. Of those alive at follow-up examination, 78% were without limitation of activity.

Adolescent↗
PubMed1992

Mitral valve repair using Carpentier techniques in patients more than 70 years old. Early and late results.

BACKGROUND: Mitral valve incompetence in elderly patients raises the problem of whether to replace or to repair the mitral valve. The purpose of this study is to review our experience with mitral valve repair in patients > 70 years old. METHODS AND RESULTS: Between 1986 and 1991, 79 consecutive patients > 70 years old underwent mitral valve repair by Carpentier techniques. The most frequent cause was degenerative valve disease (65 of 79). Preoperative echocardiography showed that 6% of the patients had type I, 88% type II, and 5% type III mitral valve dysfunction. Anatomic lesions encountered at surgery confirmed the preoperative echocardiographic findings, with 88% of the patients with a leaflet prolapse either of the posterior leaflet (56%) or of both the anterior and posterior leaflets (32%). Multiple surgical procedures were required in each patient. Posterior leaflet resection was the most common technique used (76%). Prosthetic ring annuloplasty was used in 96% of patients. Associated procedures were performed in 21.5% of cases. Three patients died, for an operative mortality of 3.8%. One patient (1.3%) required reoperation for residual mitral insufficiency. Nonfatal complications related to the patients' preoperative condition were noted in more than half of the patients. Echocardiography obtained before discharge revealed absent or minimal mitral insufficiency in 91% of patients and mild mitral insufficiency (2+/4+) in 9%. Follow-up was available for 74 of 76 patients (97.3%) and ranged from 3 months to 6 years (mean, 22 months). Two patients (2.6%) were lost to follow-up. Sixty patients (89%) were in New York Heart Association functional class I or II. Seven patients died and one required reoperation. Actuarial analysis of the results showed overall survival at 5 years 81 +/- 11%; freedom from thromboembolism, hemorrhage, and reoperation 97 +/- 5%, 97 +/- 5%, and 98 +/- 4%, respectively. Color-coded echo Doppler studies obtained in 67 patients at the time of follow-up showed absent or minimal MI (91%) (n = 61), and mild MI in 9% (n = 6). CONCLUSIONS: These data suggest that mitral valve repair using Carpentier techniques should now be considered as the procedure of choice in patients of any age referred for mitral insufficiency.

Actuarial Analysis↗
PubMedDate not supplied

Long term follow up study of prognostic significance of exercise duration during treadmill stress test in patients with stable coronary heart disease.

Treadmill stress tests provide useful noninvasive prognostic information in patients with coronary heart disease (CHD). The present study has prospectively analysed the long term prognostic value of exercise tolerance as measured by exercise time during treadmill stress test in 335 consecutive patients with stable CHD. 161 had exercise time of 6 minutes or less (mean 4.58 +/- 1.54 minutes) on a modified protocol (Group A) and 174 had exercise time of more than 6 minutes (mean 9.30 +/- 0.74 minutes)(Group B). Both groups were matched for major coronary risk factors (hypertension, smoking, diabetes and cholesterol levels) and type of drug therapy (betablockers, nifedipine, diuretics and aspirin). The patients have been followed up for upto 9 years with a mean of 6.28 +/- 2.99 years (Group A) and 7.87 +/- 1.98 years (Group B). Actuarial analysis shows that the overall survival after dropout due to death or coronary artery bypass surgery was significantly lower in group A [dropouts = 66 (41.0%)] than in Group B [dropouts = 19 (10.9%)] (Logrank test = 39.94, p < 0.001). The mortality was significantly higher in Group A with 58 deaths (36.0%) as compared to Group B with 16 deaths (9.2%) (x2 = 34.98, p < 0.001). The crude death rate was 5.73% per year in Group A as compared to 1.17% per year in Group B. The incidence of sudden deaths was also higher in Group A with 28(17.4%) instances as compared to 5(2.9%) in Group B (x2 = 19.85, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1978

Survival in peptic ulcer.

The present study of the prognosis in peptic ulcer comprises (1) an analysis of deaths caused by the disease itself, and (2) an independent actuarial analysis of life expectancy. The computations are based on 235 deaths that occurred among 1905 patients with peptic ulcer who constituted a random sample of the occurrence of ulcer disease in an area of Denmark comprising half a million inhabitants. The two methods of analysis both showed that peptic ulcer does influence the survival, but the excess of deaths was small and, in the case of solitary peptic ulcer, was present only in the first year or two after the diagnosis. The prognosis tended to be more serious in gastric ulcer than in duodenal ulcer, but the difference was not significant. In duodenal ulcer the survival tended to be better when only a deformed bulb was present. The life expectancy was not significantly different for men and women. Patients with combined gastric and duodenal ulcers had a fatality twice as great as those with solitary ulcers. No excess of deaths was found in patients under the age of 50 years at diagnosis. The duration of prediagnostic symptoms was not predictive for the prognosis.

Adult↗
PubMed1977

Long-term follow-up after isolated aortic valve replacement.

Follow-up information was obtained for 1,127 patients having had isolated aortic valve replacement between May, 1963 and April, 1976. The mean follow-up period was 4.4 years. Valves employed included Starr-Edwards Models 1000 (83 patients), 1200 (203 patients), 1260 (435 patients), and 2320 (52 patients), as well as homograft valves (103 patients) and porcine xenograft valves (251 patients). The over-all mortality rate was 7.6 percent, and the linear attrition rate thereafter was 2.7 percent per year. Long-term survival was found to be significantly related to the following preoperative variables: age, congestive heart failure, functional class, radiographic cardiac enlargement, history of acute or remote myocardial infarction, valvular lesion, left atrial mean pressure, pulmonary artery mean pressure, coronary artery disease, left ventricular angiogram, and cardiac index. From this analysis, we conclude that aortic valve replacement in asymptomatic severe aortic regurgitation, (AR) is indicated. Actuarial analysis of prosthetic valve-related death and complications suggest that the porcine xenograft valve is an excellent choice for aortic valve replacement.

Adolescent↗
PubMed1992

Combination therapy with oral ursodeoxycholic and chenodeoxycholic acids: pretreatment computed tomography of the gall bladder improves gall stone dissolution efficacy.

In a five year study, 55 patients with radiolucent gall stones were treated with the combination of 7.5 mg chenodeoxycholic acid (CDCA) and 5.0 mg ursodeoxycholic acid (UDCA)/kg/day--that is, half the monotherapeutic doses. Side effects were few but four patients could not tolerate the prescribed bile acids because of diarrhoea or nausea. Analysis of fasting duodenal bile confirmed that CDCA+UDCA converted supersaturated into unsaturated bile but the saturation indices did not predict the dissolution response. By actuarial analysis, the confirmed (by ultrasound x2) complete gall stone dissolution rates in all 55 patients were mean (SEM) 29 (7)% at 12 and 44 (8)% at 24 months. The advent of routine computed tomography before treatment enabled comparison of dissolution efficacy in those screened by computed tomography (n = 24), whose maximum gall stone attenuation was less than 100 Hounsfield units, with that in those not screened (n = 29). Although stone size and number were comparable, patients screened by computed tomography had significantly better dissolution rates (p less than 0.025) than those not screened in this way. At 12 months, partial or complete gall stone dissolution rates were 93 (7)% in the screened and 55 (11)% in the non-screened patients. At 18 months, complete dissolution rates were 64 (12%) and 20 (9)% respectively. Computed tomography before treatment is cost effective in selecting those patients likely to achieve gall stone dissolution on treatment with UDCA+CDCA.

Adult↗
PubMed1992

[Progression to AIDS among HIV-seropositive hemophiliacs].

PURPOSE: To assess the incidence of AIDS, along with its origin and mortality rate, in a group of sero-positive haemophiliacs with long follow-up. MATERIAL AND METHODS: The progression into AIDS in 94 HIV-seropositive haemophiliacs (88 with haemophilia A and 6 with haemophilia B) followed since 1986 has been analyzed. The mean age was 19 years and 64% of the patients had severe haemophilia. All of them had been previously treated with non virus-inactivated factor concentrates. Was detected HIV antigen in 13 of them and 32 were treated with zidovudine. Actuarial analysis started from seroconversion date or from the first positive result and the average observation time was 90 months (5-97). RESULTS: Sixteen patients developed AIDS, resulting in an eight-years accumulative actuarial indice of about 24%. AIDS incidence was lower (p less than 0.0001) in haemophilia A (21%) than in haemophilia B (67%). The eight-years progression rate to AIDS showed a significant dependence on patient age, it being higher in patients aged greater than 30 (77%) than in those aged 15-30 (30%) and less than 15 (9%). Patients who presented CD4+ counts lower than 0.5 x 10(9)/L or CD4/CD8 ratios lower than 0.5 at the beginning of the observation period had a greater 8-year AIDS incidence (63% and 57% respectively) than the remaining patients (16% and 12%). At AIDS diagnosis, all patients had CD4+ lymphocyte counts lower than 0.2 x 10(9)/L, two had detectable HIV antigenaemia and six had been previously treated with zidovudine. The cause of AIDS was an opportunistic infection in all the cases namely, P. carinii pneumonia and candidiasis, but no secondary neoplasia was registered. Nineteen patients died during the follow-up, 12 because of AIDS and 7 because of other reasons unrelated to HIV-infection. CONCLUSION: Our results suggest that 25% of the haemophiliacs will develop AIDS eight years after seroconversion, and a decreasing incidence is not observed. Lower progression rate to AIDS in children than in adults is confirmed.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Influence of mild to moderate treated hypertension on 9-11 year mortality in patients with pre-existing coronary heart disease.

Hypertension is a known risk factor in the genesis of coronary artery disease. However, the effect of pre-existing hypertension on the long-term mortality in patients with established coronary heart disease is not clear. The present cohort study analysed the influence of baseline mild to moderate treated hypertension in cases of known coronary heart disease with cardiac mortality as end point. Data from a cohort of 511 patients including 266 normotensives and 245 controlled hypertensives was analysed over a follow-up period of 9 to 11 years. The baseline data were identical regarding other major risk factors like age, gender, smoking, diabetes, cholesterol levels and congestive heart failure on univariate analysis. There were more cases of myocardial infarction in the normotensive group. The number of patients receiving beta-blockers or aspirin were similar in both groups. However, more patients in the hypertensive group received nifedipine. Actuarial analysis of survival showed that mortality was the same in both groups with an overall cardiac mortality of 65 (26.5%) in the hypertensive group and 86 (32.3%) in the normotensive group (P greater than 0.1). The survival curves also showed no significant difference in mortality at any point in time (logrank test = 2.37, P greater than 0.1). Analysis of mortality after adjusting for myocardial infarction at first presentation also showed no significant difference. These data indicate that in patients with coronary heart disease the presence of mild to moderate hypertension does not add to the risk of cardiac mortality.

Adrenergic beta-Antagonists↗
PubMed1977

The use of "fresh" unstented homograft valves for replacement of the aortic valve: analysis of 6 1/2 years experience.

Between August 1969 and January 1976, 561 patients underwent homograft replacement of the aortic valve (AVR). Isolated AVR was performed in 339 patients, ranging in age between 18 months and 74 years. The valves were sterilized in antibiotic solution and preserved at 4 degrees C in tissue culture medium. There were 11 early deaths (3.2%) and 23 late deaths (6.8%). Actuarial analysis showed 88% survival at 5 years and 85% at 6 years. Valve failure occurred in 13 patients (3.8%) due to prolapse of one cusp in five patients (1.5%), infective endocarditis in three and degeneration of the graft in five (1.5%). Degenerative valve failure was encountered after the fourth year with an incidence of 3.5% of patients at risk, and occurred only in grafts from donors over the age of 70 years. Diastolic murmurs were present in 22% of patients followed up for more than one month and increased very slightly with time. The clinical result was judged to be good or excellent in approximately 90% of the surviving patients.

Adolescent↗