SEARCH · PubMed Health

Results for “Life Table Method”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 685 records · Page 38Linked to original sources

PubMed1990

High grade vesicoureteral reflux: analysis of observational therapy.

Between 1981 and 1987, 300 patients with high grade (III, IV and V international classification) vesicoureteral reflux were treated at a single pediatric hospital. Only patients with primary vesicoureteral reflux were included in the study. The guiding principle during this period was that all patients with high grade vesicoureteral reflux would be observed on prophylactic antibiotics (observational therapy) and surgical correction would be reserved for specific indications. Of the 300 patients 132 received observational therapy alone and 168 required surgical correction for specific indications after varying periods of observation. In both groups the duration of persistent reflux was analyzed using a life-table method. In patients with grade V reflux we observed resolution in 3 patients whereas 23 required surgical correction. Of those patients in the observation group with grade IV reflux 83% had persistent reflux at 2 years and 70% still had reflux at 5 years. For those with grade III reflux the persistence rate was 83% and 50%, respectively. Neither age, sex nor side of reflux had a correlation with the rate of resolution. When tested grade of reflux correlated loosely (p = 0.07). During the period of observational therapy new renal scars developed in 23 patients (8%). We conclude that high grade vesicoureteral reflux can resolve in a minority of patients over a protracted interval. On the basis of this analysis, we advocate consideration of surgical correction in these patients after a 4-year period of observational therapy and for specific indications.

Adolescent↗

PubMed1984

Ranitidine and cimetidine in prevention of duodenal ulcer relapse. A double-blind, randomised, multicentre, comparative trial.

In a comparative trial of preventive medication for duodenal ulceration with 51 participating centres, 484 patients were recruited for a year's maintenance treatment with the recommended bedtime dose of ranitidine (150 mg; n = 243) or cimetidine (400 mg; n = 241). These outpatients had recently healed duodenal ulcers, confirmed by endoscopy before and after healing, and ulcer relapse was monitored by endoscopy every 4 months. The distribution of factors likely to influence ulcer recurrence was similar in the two treatment groups. A life-table method of analysis showed that the ulcer relapse rate was consistently and significantly lower on ranitidine that on cimetidine (8% v 21%, p = 0.0018 at 4 months; 14% v 34%, p less than 0.0001 at 8 months; and 23% v 37%, p = 0.004 at 12 months). Crude relapse rate calculations, which underestimate the probability of ulcer recurrence, also confirmed the significant superiority of ranitidine 150 mg over cimetidine 400 mg nightly in preventing ulcer recurrence throughout the year.

Adult↗

PubMed1984

A clinical epidemiologic study of thyroid carcinoma in Malmö, Sweden.

The annual incidence of clinically diagnosed TC in Malmö was, on an average, 2.4 per 100,000 population during the years 1960-1977. This was 1.2 per 100,000 population lower than the corresponding incidence in the whole of Sweden as reported by the National Cancer Registry. The main reason for the difference was suggested to be inclusion in the official figures of autopsy cases and of cases with a benign diagnosis, rather than a true difference in the prevalence of TC. During the later part of the study an increase in the incidence of differentiated TC of approximately 70% was noted. This was considered to be due to increased health awareness and the availability of medical care, because only the number of tumors with less advanced growth increased. The average annual mortality from TC in Malmö was 0.9 per 100,000, which was 0.4 per 100,000 lower than the corresponding official rate in all of Sweden. The difference was suggested to be mainly due to inclusion in the official figures of persons not dying of TC. The mortality did not change significantly during the period of investigation. The percentage distribution by histologic type of tumors clinically diagnosed (N = 104) was as follows: papillary cancer, 65%; follicular, 21%; medullary, 4%; and anaplastic, 12%. The prognosis as estimated by the life table method was worst for patients with anaplastic TC, followed by those with follicular, papillary, and medullary TC. The validity of using the relationship of the tumor to the thyroid capsule (i.e., intrathyroidal and extrathyroidal growth) as a basis for classification into tumor stages was supported in the present study: the mortality in patients with intrathyroidal tumors was lower than in those with extrathyroidal tumors. The definition of occult TC--TC not larger than 1.5 cm, without regard to the relation to the thyroid capsule--was considered inappropriate and a change in the conception of occult TC was proposed. The presence or absence of node metastases in TC did not seem to have major significance for the prognosis. The significance of age for survival was strongly supported in our study. Deaths from TC clinically diagnosed before the age of 60 were infrequent, whereas the disease after this age increasingly often was fatal. This was partly due to a late onset of anaplastic TC and partly to a higher mortality in older than in younger patients with papillary or follicular TC.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

PubMed1988

Incidence of second neoplasms in patients with bilateral retinoblastoma.

The cumulative incidence of second neoplasms in 215 patients with bilateral retinoblastoma was calculated using the life-table method. Second tumors developed in 4.4% of the patients during the first 10 years of follow-up, in 18.3% after 20 years, and in 26.1% after 30 years. The 30-year cumulative incidence was 35.1% for the 137 patients who received radiation therapy compared with an incidence rate of 5.8% for the 78 patients who did not receive radiation. In the 137 patients who received radiation, second tumors developed both inside and outside the field of therapy. There was a 30-year incidence rate of second tumors of 29.3% within the field of irradiation and 8.1% outside the field. The rate outside the field of irradiation (8.1%) was similar to that observed in nonirradiated patients (5.8%). Our findings indicate that carriers of the retinoblastoma gene have an increased incidence of second tumors, and that the incidence rate is further increased in patients who receive radiation therapy.

Child, Preschool↗

PubMed1991

Uveal melanoma and pregnancy. A report of 16 cases.

A review of 3706 consecutive patients with uveal melanoma over a 17-year period revealed that 16 patients (0.4%) were pregnant women at the time of diagnosis. The mean age at presentation in this group was 30 years and the mean months of gestation at the time of diagnosis of the posterior uveal melanoma was 6 months. Seven of the sixteen tumors were active uveal melanomas at the initial examination and were treated immediately, while the remaining nine tumors were initially diagnosed as suspicious choroidal nevi or dormant choroidal melanomas, seven of which grew into active melanomas during the course of the pregnancy, necessitating therapy. The tumors were managed by enucleation in 10 cases, plaque radiotherapy either during or after pregnancy in 4 cases, and observation in 2 cases. Histopathologically, the melanomas did not differ appreciably in cell type, mitotic activity, and other features when compared with a matched group of tumors in nonpregnant women. All of the patients who elected to carry the pregnancy to term (14 cases) delivered healthy babies with no placental or infant metastases. The 5-year survival rate using the life table method in these pregnant women with posterior uveal melanoma is 71% and is similar to the survival of nonpregnant women with posterior uveal melanoma reported in other series.

Adolescent↗

PubMed1986

Stage III carcinoma of cervix. The importance of increasing age and extent of parametrial infiltration.

The relative importance of a number of potential prognostic factors was analysed for a sequential group of 296 patients with stage III carcinoma of the cervix who had been treated in a mature prospective clinical trial. Using a log-rank analysis of survival curves generated by the life-table method increasing age (p = 0.05) and extent of parametrial infiltration (p = 0.001) were found to be significantly related to prognosis. These two factors were further demonstrated to be independent variables and, of the two, parametrial extension (p = 0.002) was more significant than increased age (p = 0.035). Involvement of the lower third of the vagina, the presence of bullous oedema and the histological differentiation of the disease were not prognostically significant in this study. It is suggested that tumour volume as defined by extent of parametrial infiltration is a sufficiently good prognostic factor to be incorporated into a revised staging system.

Adenocarcinoma↗

PubMed1986

Effect of continued ultraviolet B phototherapy on the duration of remission of psoriasis: a randomized study.

Phototherapy using sunburn spectrum ultraviolet radiation (UVB) is now a frequently utilized treatment for psoriasis that is extensive or has not responded to topical preparations. Four university centers performed a prospective randomized clinical trial to compare remission times of patients with psoriasis who continued UVB phototherapy after initial clearing with this therapy and patients whose UVB phototherapy was discontinued within 3 weeks of clearing. As assessed by life table methods, the time to flare after initial clearing for patients on UVB maintenance therapy was significantly longer than for patients who discontinued UVB within 3 weeks after initial clearing. Our data suggest that continuing UVB phototherapy after initial clearing contributes to the duration of disease control and is justified for many patients.

Actuarial Analysis↗

PubMed1985

Spermarche--the age of onset of sperm emission.

Gonad maturation in boys is not characterized by a critical visible event such as menarche in girls. Establishing spermatogenesis by masturbation in maturing boys may be considered inappropriate. In order to estimate the median age of spermarche, a group of 155 normal schoolboys were examined twice (ages 12 and 13 years) for the occurrence of sperm in the first voided morning urine. The boys were requested to bring a daily sample for 10 consecutive days. Over 90% brought at least two samples and 50% brought 5-10 samples. The rate of boys with spermaturia at each age was calculated by the life-table method to adjust for the varying number of samples. New spermaturia was detected with each additional sample in the boys who brought in a greater number of samples. The urine examination carried a considerable false negative rate; even in boys who brought five or more samples, over 40% of boys positive at age 12 were negative at age 13. The rate of spermaturia at age 12 years was 37.5%, and at age 13 it was 68.9%. Our previous report showed the rate at age 11 years to be less than 1%. Because of an uncertain number of false negatives, these are probably under estimates of the true rate of spermatogenesis. The occurrence of spermarche was significantly associated with maturation of secondary sex characteristics.

Actuarial Analysis↗

PubMed1991

Minimal change nephrotic syndrome in adults: response to corticosteroid therapy and frequency of relapse.

Rate of response to a corticosteroid and frequency of relapse were studied in 33 patients with adult-onset minimal change nephrotic syndrome (MCNS). Of these, 28 patients were treated with oral prednisolone (PSL) at 1 mg/kg/d for from 4 to 8 weeks depending on their response, followed by PSL, at gradually tapering doses for 1 year. Five severely nephrotic patients received 1 g of methylprednisolone intravenously (IV) for 3 days, followed by 40 mg/d oral PSL for 4 to 8 weeks and finally PSL in gradually reduced doses. Sixteen patients (48%) were free of proteinuria within 4 weeks, and 25 (76%) within 8 weeks. Two patients required cyclophosphamide for induction of remission. Age at presentation was not significantly correlated with response time to corticosteroid therapy. Thirty-two (97%) went into remission, and relapse occurred in 11 (34%) of these. As assessed by the life-table method, 84% of patients were still in remission at 6 months after induction of remission, 75% after 1 year, and 63% during the follow-up period (mean, 47.1 +/- 29.1 months; range, 6 to 123 months). Incidence of relapse was not correlated with remission induction time, ie, earlier (less than or equal to 4 weeks) or later (greater than 4 weeks), but was greater in younger (less than 30 years of age) patients than older (greater than or equal to 30 years) patients (P less than 0.03). At the last follow-up, 31 patients (94%) were in complete remission and had normal renal function.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1982

Natural history of "silent" lupus nephritis.

Twenty patients with systemic lupus erythematosus but without evident renal involvement previously underwent percutaneous renal biopsy. Findings revealed almost universal pathologic evidence of nephritis. Included were three patients who had diffuse proliferative changes and five who had subendothelial electron dense deposits. Only four patients developed clinical renal disease during the follow-up period while no patient died or required dialysis. Using the Life Table Method, the cumulative percentage of patients free from any clinical renal disease was over 60% at 10 yr from the time of diagnosis of systemic lupus, and at 8 yr from the time of the original biopsy. It is concluded that silent lupus nephritis, regardless of histologic subtype, has a favorable prognosis. These data may not be applicable to patients with similar biopsies who have evidence of clinical lupus nephritis.

Actuarial Analysis↗

PubMed1984

Iga nephropathy: presentation, clinical course, and prognosis in children and adults.

Eighty-two patients, 56 male and 26 female, biopsied since 1972 had IgA nephropathy. At the time of kidney biopsy, 24 patients were children and 58 were adults. In both groups the clinical course was documented in sufficient detail to allow prediction of disease outcome. Twenty-six (45%) of the adult patients had chronic renal insufficiency either at first evaluation or subsequently. Fourteen eventually required chronic hemodialysis. Hypertension as the initial sign of disease was seen more frequently in patients with chronic renal insufficiency. Adult males were more likely to have chronic renal insufficiency. The life table method was used to predict age at initiation of dialysis and kidney survival from date of onset of clinically apparent disease. Thirty-five percent of the male patients were predicted to require dialysis by age 40. Kidney death was predicted at 10 years from onset for 33% of male and 22% of all patients biopsied as adults. While all patients with progressive disease had over 2.0 g/24 h urinary protein excretion at least once, many individuals with serum creatinine concentration below 1.5 mg/dL showed marked fluctuation in degree of proteinuria, often exceeding 2.0 g/24 h. Thus, in some cases, degree of proteinuria was not a reliable predictor of outcome.

Adolescent↗

PubMed1999

Collapsing glomerulopathy: clinical characteristics and follow-up.

In 1986, Weiss et al reported a group of patients with nephrotic syndrome, progressive chronic renal failure, and the histopathologic features of glomerular capillary collapse. Similar lesions are often described in human immunodeficiency virus (HIV) nephropathy. We evaluated 893 consecutive nontransplant renal biopsies performed in our department and the follow-up of the patients at our outpatient service. Sixteen specimens were identified with the pathological features of collapsing glomerulopathy (focal segmental or global glomerular capillary collapse and visceral epithelial cell hyperplasia), with no evidence of HIV infection and/or intravenous drug abuse. Their clinical characteristics were analyzed and compared with a group of 29 patients with noncollapsing focal segmental glomerulosclerosis (FSGS). The follow-up period of both patient groups was 5 +/- 1.46 years. The Kaplan-Meier life table method was used to present survival of the patients. The age of both groups was similar, 34 +/- 4 years (mean +/- standard error of the mean) for patients with collapsing glomerulopathy and 35 +/- 3 years for those with FSGS. The serum creatinine level was greater in patients with collapsing glomerulopathy (183 +/- 31 micromol/L) compared with those with FSGS (115 +/- 18 micromol/L), but the difference was not significant (P = 0.0504). The difference in proteinuria was not significant (P = 0.7668); it was 5.83 +/- 0.74 g/d in patients with collapsing glomerulopathy and 5.42 +/- 0.84 g/d in those with focal sclerosing glomerulonephritis. The difference in systolic (P = 0.4) and diastolic blood pressure (P = 0.556) was also not significant. Survival of the patients with collapsing glomerulopathy was worse than that of patients with FSGS (P = 0.025). Renal function survived 5 years in 40% of the patients with FSGS, but patients with collapsing glomerulopathy had no renal function survival. Our data suggest that idiopathic collapsing glomerulopathy is a distinct clinicopathologic entity with similar clinical features to focal sclerosing glomerulonephritis, but a worse prognosis and a rapidly progressive course toward end-stage renal disease.

Adolescent↗

PubMed2004

Supraclavicular first rib resection and total scalenectomy: technique and results.

The supraclavicular approach has been a successful route for thoracic outlet decompression. It permits many more options than the transaxillary route. Anterior and middle scalenectomy, together with brachial plexus neurolysis can be performed with excellent exposure. The same incision can be used to perform cervical or first rib resection, although the success rate is not significantly improved by removing ribs. The 5-year success rate for scalenectomy with or without first rib resection using life table methods is approximately 70%.

Axilla↗

PubMed2001

The risk of developing breast cancer within the next 5, 10, or 20 years of a woman's life.

BACKGROUND: The lifetime risk of developing breast cancer is a frequently misinterpreted statistic. Risk projections over a shorter time period, conditioned on current age, may be less prone to misconceptions and more relevant to populations at different ages. The purpose of this study was to estimate the risk of developing breast cancer within the next 5, 10, or 20 years for women currently aged 30 to 70 years in California's four major race/ethnic groups. METHODS: Life tables were used to obtain risk estimates based on 1993-1997 breast cancer incidence rates from the California Cancer Registry and statewide mortality rates. RESULTS: For women currently aged 50, the estimated risk of developing invasive breast cancer within 5 years varied from 0.8% (1 in 133) among Hispanics to 1.3% (1 in 75) among Caucasians. Risk estimates within 10 years were 2.9% (1 in 34) among Caucasians, 2.3% (1 in 43) among African Americans, 2.0% (1 in 51) among Asian/Pacific Islanders, and 1.6% (1 in 63) among Hispanics. Within 20 years, estimated risks increased to 6.6% (1 in 15) among Caucasians, 5.0% (1 in 20) among African Americans, 3.9% (1 in 26) among Asian/Pacific Islanders, and 3.7% (1 in 27) among Hispanics. Risk estimates were 8% to 20% higher when in situ tumors were included in the calculations. CONCLUSIONS: Based on these estimates, the baseline risk of developing breast cancer in the next 1 or 2 decades of life varies by race/ethnicity and current age, but may be lower than the risk perceived by most women.

Adult↗

PubMed1997

Survivorship analysis of total knee arthroplasty with the kinematic prosthesis in patients who have rheumatoid arthritis.

Eighty-eight primary total knee arthroplasty procedures in 61 patients with rheumatoid arthritis were performed using the Kinematic total knee prosthesis (Howmedica, Rutherford, NJ) with cement between 1980 and 1985. No patients were lost to follow-up evaluation. Thirty-one of 61 patients died during the study period. Survivorship for all patients by life-table method was estimated as 56% at 10 years. This was shorter than the expected survival rate of a sex- and age-matched control group. Fifty procedure outcomes in 34 patients (27 women, 7 men) who were followed for more than 10 years were available for clinical evaluation. Complications occurred in 11 cases; in 4 of these, revision surgery was required. With revision as the endpoint, the survival rate of the prostheses was estimated as 93% at 10 years.

Adult↗

PubMed1991

Long-term results with vein homograft in femoro-distal arterial reconstructions.

There still is a need for an alternative to autologous vein especially for infra-inguinal vascular reconstructions. Since 1984 we have used a denatured venous homograft in patients in whom the saphenous vein was either absent or unsuitable. One hundred and five homografts were implanted in the femoro-popliteal and 51 in the femoro-infrapopliteal position. The results obtained were satisfactory, with a 5-year cumulative patency (life-table method) of 53% overall, 68.4% in patients with disabling claudication, and 42% in those with critical ischaemia. The cumulative aneurysm rate was rather high, at 18% after 3 years and 58% after 5 years. An excellent limb salvage rate of 85% was achieved in patients with critical ischaemia. The management of graft aneurysms and the indications for reconstructive surgery with a denatured venous homograft are discussed.

Aged↗

PubMed1988

Three years experience with denaturated venous homografts as an arterial substitute: a clinical, pathological and immunological study.

Over a three-year-period 105 peripheral arterial reconstructions were performed using a denaturated venous homograft in a group of patients with no suitable autologous vein. A retrospective analysis has been carried out to investigate the patency rate of this graft. After three years 64% of all grafts are functioning well (according to the Life Table Method, Kaplan & Meyer). No significant differences in patency rates were found between reversed autologous veins and the material tested in this study but analysis of grafts removed after failure showed obstruction due to thrombosis or aneurysmal dilatation. No evidence of an immune response to the grafts was seen.

Aged↗

PubMed1997

Re-do operations after failed multisegmental reconstructive arterial surgery for critical limb ischaemia.

The purpose of this study was to investigate the long-term graft patency rates after multisegmental arterial reconstruction for treatment of chronic critical limb ischemia, and to evaluate the role of re-do surgery in treatment of graft failure. A total of 449 aortofemoropopliteal/tibial grafts carried out over a 10-year period were retrospectively reviewed. All patients were operated upon with chronic critical limb ischemia grade III and IV according to the Fontaine classification; 221 operations were performed in one stage (group A), and 228 in two stages (group B). Distribution of graft failures in the postoperative period, re-do operations and their impact on limb salvage were investigated using life-table methods. During follow up, 62 cases of inflow graft thrombosis were observed (23 in group A and 39 in group B). To correct the inflow graft failure, 59 re-do procedures were performed (27 in group A, 32 in group B). Inflow graft failures were most common during 24 months after primary surgery. During the same period, 92 cases of isolated outflow graft thrombosis were observed (45 in group A and 47 in group B). Outflow graft thromboses were most common after 24-36 months. For treatment of recurrent symptoms caused by outflow graft thrombosis, 68 re-do operations were performed. The 5 year cumulative primary graft patency, secondary graft patency and limb salvage rates were 43.2%, 71.8% and 79.9% in group A, and 23.8%, 54% and 67.5% in group B respectively. In conclusion the long term primary graft patency rate after multisegmental aortofemoropopliteal/tibial reconstructive surgery is low and significantly lower, when compared with single segment reconstructions. Re-do operations have a positive impact on secondary long-term graft patency and limb salvage.

Adult↗