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Results for “Life Table Method”

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PubMed1995

The influence of age on operative mortality and long-term relative survival following emergency abdominal aortic aneurysm operations.

OBJECTIVE: To study operative mortality and long-term survival following emergency operations for abdominal aortic aneurysm. DESIGN: Retrospective survey in a university hospital. MATERIALS: Two hundred and twenty-seven patients with median age 72 years, (17% women). METHODS: Founded on data from the Norwegian Registrar's Office, operative mortality and long-term survival was estimated using the life-table method. Expected survival for demographically matched subgroups was calculated from death rate tables issued by the Norwegian Central Bureau of Statistics. RESULTS: Operative mortality was 41% for the 175 patients with ruptured aneurysms and 17% for the 52 with imminent rupture. The 6-year survival rate was 61% for all the successfully operated patients, and not different from that of a demographically matched population. For the patients of 72 years or older the 6-year survival rate was 53%. This was equal to that of an age and sex matched population. The younger patients had an observed 6-year survival rate of 64%, which was significantly lower than the expected of 84%. The standard mortality rate for this group was 2.25. No statistically significant difference in long-term survival was detected between the two age groups. CONCLUSIONS: Age at the time of the operation for a symptomatic abdominal aortic aneurysm does not seem to influence long-term survival. Consequently, younger patients experience a higher relative mortality compared to the older.

Adult↗

PubMedDate not supplied

Supracricoid partial laryngectomy with cricohyoidoepiglottopexy for "early" glottic carcinoma classified as T1-T2N0 invading the anterior commissure.

PURPOSE: "Early" glottic squamous cell carcinoma classified as T1-T2N0 with anterior commissure invasion is conventionnaly managed with vertical partial laryngectomy (VPL) or radiation therapy (RT). At our insitution, in the early 1980s, vertical partial laryngectomy was progressively replaced by supracricoid partial laryngectomy with cricohyoidoepiglottopexy (SCPL-CHEP). The medical files and operative charts of 62 patients with "early" glottic carcinoma classified as T1-T2N0 invading the anterior commissure, consecutively managed with cricohyoidoepiglottopexy, were retrospectively reviewed to ascertain whether any conclusions could be drawn regarding this treatment modality. MATERIALS AND METHODS: Survival, local control, nodal recurrence, distant metastasis, and metachronous second primary tumor estimate was analyzed using the Kaplan-Meier life table method. RESULTS: The 3- and 5-year actuarial survival estimate was 93.3% and 86.5%, respectively. The 3- and 5-year actuarial local control estimate was 98.2%. The only patient with local recurrence was successfully salvaged with RT resulting in an overall 100% local control rate and laryngeal preservation rate. The 3- and 5-year actuarial nodal recurrence estimate was 1.8%. The 3- and 5-year actuarial distant metastasis estimate was 0% and 2%, respectively. Aspiration related completion total laryngectomy and permanent tracheostomy never occurred. CONCLUSION: The present retrospective study suggests that cricohyoidoepiglottopexy for glottic carcinoma classified as T1-T2 invading the anterior commissure resulted in higher local control rates and overall laryngeal preservation rate when compared with historical series using either VPL or RT. Further series are warranted to confirm our results.

Adult↗

PubMed2000

Prognostic significance of cytogenetic abnormalities of chromosome arm 12p in childhood acute lymphoblastic leukemia: a report from the Children's Cancer Group.

BACKGROUND: The authors have determined the prognostic significance of cytogenetically detectable 12p abnormalities, which are frequent in children with acute lymphoblastic leukemia (ALL), in a large cohort of patients treated on risk-adjusted protocols of the Children's Cancer Group (CCG). METHODS: The presence of an abnormal 12p was identified among 1880 children with newly diagnosed ALL; outcome was assessed by standard life table methods. RESULTS: A total of 174 cases (9%) had cytogenetically detectable 12p abnormalities; the majority of cases had a balanced translocation, a del(12p), or an add(12p). In the overall cohort, event free survival (EFS) at 6 years was similar for patients with or without a 12p abnormality (76%, SD = 6%, vs. 75%, SD = 2%, respectively; P = 0.60). Among patients with pseudodiploidy, an abnormal 12p conferred improved outcome (P = 0.008; relative risk = 0.51; 95% confidence interval [CI], 0.31-0.85). There was a trend for improved EFS for those with abnormalities in both chromosome 12 homologues (P = 0.16; relative risk = 0.39; 95% CI, 0.10-1.55) and those with low hyperdiploidy (P = 0.07; relative risk = 0.44; 95% CI, 0.18-1.09). Among T-lineage ALL patients, there was a trend for worse outcome for abnormal versus normal 12p (P = 0.14; relative risk = 1.97; 95% CI, 0.78-4.93). There was no difference in EFS for the 12 patients with a dic(9;12) compared with patients lacking an abnormal 12p. CONCLUSIONS: These data suggest that although a cytogenetically detectable 12p aberration is a favorable risk factor for children with ALL and pseudodiploidy, it is not prognostic for the overall group of pediatric ALL patients treated with contemporary therapies of the CCG.

Adolescent↗

PubMed1995

Centralized registration, prophylactic examination, and treatment results in improved prognosis in familial adenomatous polyposis. Results from the Danish Polyposis Register.

BACKGROUND: Over the last few decades numerous regional and national registers have been established all over the world with the aim of improving survival in familial adenomatous polyposis (FAP). The Danish Polyposis Register was founded in 1971 and coordinates the screening and subsequent prophylactic colectomy of FAP patients. METHODS: The crude cumulative survival in 321 patients (205 probands and 116 call-up cases) with verified FAP was calculated in accordance with the life-table method. RESULTS: At the time of diagnosis of FAP only 2 of 116 (2%) had colorectal cancer versus 142 of 205 probands (69%). The 10-year cumulative survival was 94% (95% confidence limits, 89-99) in call-up cases compared with only 41% (34-49) in probands (p < 0.00001), and survival improved significantly (p < 0.00001) after the establishment of the Danish Polyposis Register. CONCLUSION: The establishment of a centralized polyposis register has resulted in a substantial improvement of the prognosis in FAP.

Adenomatous Polyposis Coli↗

PubMed2002

Cost effectiveness of esomeprazole compared with omeprazole in the acute treatment of patients with reflux oesophagitis in the UK.

BACKGROUND: Clinical studies have demonstrated that esomeprazole is superior to omeprazole for the acute treatment of reflux oesophagitis. OBJECTIVE: To compare the cost effectiveness of esomeprazole 40mg once daily with omeprazole 20mg once daily in patients with reflux oesophagitis. METHODS: Pooled data were used from three 8-week clinical trials comparing the efficacy and safety of esomeprazole 40mg once daily and omeprazole 20mg once daily for the acute treatment of reflux oesophagitis. A simple decision analysis model, using UK direct medical costs, compared the cost effectiveness of the two treatments. Healing probabilities derived from the clinical studies using the Life Table method were used to estimate the effectiveness and cost of treating 100 patients with reflux oesophagitis. Patient management assumptions were based on a clinical management survey involving 25 UK physicians. PERSPECTIVE: UK National Health Service. RESULTS: After 4 weeks' therapy, the Life Table estimated the oesophageal healing rate to be 77.7% in esomeprazole 40mg once-daily recipients (n = 2446), compared with 67.6% in omeprazole 20mg once-daily recipients (n = 2431; p < 0.001). The corresponding values after 8 weeks' treatment were 93.4% and 86.2%, respectively (p < 0.001). The model predicted that when considering healing probabilities over 8 weeks, esomeprazole 40mg once daily produced total direct cost savings of pound1290 (14%) when compared with omeprazole 20mg once daily. When considering the cost of treating patients who had failed treatment (defined as patient not healed as assessed by endoscopy) after 8 weeks, the cost advantage for esomeprazole was even greater. CONCLUSION: Esomeprazole 40mg once daily is cost effective compared with omeprazole 20mg once daily in the acute treatment of patients with reflux oesophagitis; esomeprazole provides greater effectiveness at a lower cost.

Anti-Ulcer Agents↗

PubMed1994

The risk of endometrial cancer in hereditary nonpolyposis colorectal cancer.

PURPOSE: Hereditary nonpolyposis colorectal cancer (HNPCC) is characterized by increased risk for cancer, especially colorectal cancer. It has been recommended that colon cancer control programs for family members be expanded to include endometrial cancer, the commonest extracolonic cancer observed in HNPCC families. We estimated the age-specific and cumulative endometrial cancer risk for women at high risk for HNPCC. PATIENTS AND METHODS: Family history data from three large HNPCC registries were combined for this study. High risk family members were identified without regard to extracolonic cancer. Life table methods were used to calculate estimates of risk. RESULTS: One thousand eighteen women from 86 families were included in the study. Cumulative incidence was 20% by age 70, compared to 3% in the general population. Risk was highest in women most likely to carry the HNPCC gene (P < 0.001). In this group, during the highest risk years (age 40 to 60), average annual risk exceeded 1%. There was no significant difference among the registries, despite different ascertainment practices regarding endometrial cancer. CONCLUSION: Interventions to reduce endometrial cancer morbidity and mortality are justified by the risk levels observed. Prophylactic total hysterectomy and bilateral salpingo-oophorectomy should be recommended to women in HNPCC families who have a syndrome cancer or offspring with a syndrome cancer. Endometrial cancer screening should be available to women at high risk. Studies of screening protocols are needed.

Colorectal Neoplasms, Hereditary Nonpolyposis↗

PubMed1985

Statistical comparison of Pearl rates.

Statistical procedures for hypothesis testing and interval estimation of the difference in a pair of Pearl rates are presented. The p value of the test statistic is evaluated exactly from the binomial distribution or approximately from the standard normal distribution. Interval estimation is provided by the test-based method of Miettinen. The procedures are applied to two published data sets, and the conceptual link between the Pearl rate and life-table methods is discussed.

Actuarial Analysis↗

PubMed1996

Prognostic role of oestrogen and progesterone receptors in patients with breast cancer: relation to age and lymph node status.

AIMS: To consider the prognostic role of oestrogen receptor and progesterone receptor status in relation to the age at surgery, length of follow up and lymph node status. METHODS: The study population comprised 977 patients with histologically confirmed breast carcinoma, with a median follow up of nine years. The actuarial life table method was used to test for survival differences. The Cox proportional hazard model was used to test for interaction effects between each hormone receptor and age, lymph node status and length of follow up. As the analysis involved multiple subgroups, significance was set at the 1% level (p < 0.01). RESULTS: When the patients were subdivided into groups according to lymph node status and age, progesterone and oestrogen receptor status predicted prognosis in middle aged (46-60 years) patients with lymph node positive breast cancer. Their prognostic effect in this subgroup, however, was restricted to the first five years after surgery. Progesterone receptor status was the strongest predictor of outcome. CONCLUSION: The prognostic power of oestrogen and progesterone receptor status varies depending on age, lymph node status and length of follow up after surgery.

Adult↗

PubMed1994

Correlates of employment after AIDS diagnosis in the Boston Health Study.

OBJECTIVES: The purpose of this study was to determine the impact of personal and job characteristics on the time to employment loss after diagnosis of the acquired immunodeficiency syndrome (AIDS) and to examine how job loss affects patients' income. METHODS: Data were collected from 305 patients with AIDS at three sites in Boston, Mass, between February 1990 and July 1991. Life-table methods were used to estimate the number of months employed after diagnosis. A Cox proportional hazards model was used to estimate the effect of risk factors on the probability of ceasing employment in a month. RESULTS: Seventy-six percent of respondents were working at the time of diagnosis; 53% still had a job at the time of the baseline interview, which averaged 16 months later, but about one in three was on sick or disability leave. Mental and physical demands of jobs significantly influenced the likelihood of employment loss. The loss of earnings reduced monthly income by 75%. CONCLUSIONS: Job characteristics affect the likelihood of employment loss, which in turn has a deleterious effect on income. Programs supporting persons with AIDS during the transition out of work or enabling them to modify their job demands may also reduce these problems.

Acquired Immunodeficiency Syndrome↗

PubMed2005

Influence of level of education on disability free life expectancy by sex: the ILSA study.

PURPOSE: To assess the effect of education on Disability Free Life Expectancy among older Italians, using a hierarchical model as indicator of disability, with estimates based on the multistate life table method and IMaCh software. METHODS: Data were obtained from the Italian Longitudinal Study on Aging which considered a random sample of 5632 individuals. RESULTS: Total life expectancy ranged from 16.5 years for men aged 65 years to 6 years for men aged 80. The age range for women was 19.6 and 8.4 years, respectively. For both sexes, increasing age was associated with a lower probability of recovery from a mild state of disability, with a greater probability of worsening for all individuals presenting an independent state at baseline, and with a greater probability of dying except for women from a mild state of disability. A medium/high educational level was associated with a greater probability of recovery only in men with a mild state of disability at baseline, and with a lower probability of worsening in both sexes, except for men with a mild state of disability at baseline. DISCUSSION: The positive effects of high education are well established in most research work and, being a modifiable factor, strategies focused on increasing level of education and, hence strengthening access to information and use of health services would produce significant benefits.

Aged↗

PubMed1992

Results of surgical treatment of patients with Crohn's disease.

A follow-up study of 98 patients suffering from Crohn's disease was performed to evaluate the recurrence rate of the disease and the patients' ability to cope socially with this chronic disease. Eight patients were decreased and one had emigrated, thus 89 of the patients were contacted. Two of the patients had died of Crohn's disease and another two had died of adenocarcinoma of the large bowel involved in Crohn's disease. 83% of the patients had been operated on. The cumulative rate for recurrences resulting in reoperation using the life table method was 34% at 10 years and 55% at 20 years. Even after an enterostomy, the patients who had only large bowel involvement had the best quality of life and were most able to work. On the other hand, due to the higher recurrence rate, operated patients with both small and large bowel involvement found it most difficult to cope with the disease.

Activities of Daily Living↗

PubMed2000

Cross-sectionally derived hysterectomy prevalence for correcting uterine and ovarian cancer incidence rates and probabilities.

PURPOSE: This paper presents a cross-sectional method for deriving age-specific hysterectomy prevalence. The influence of hysterectomy prevalence on uterine and ovarian cancer incidence rates and probabilities is illustrated.METHODS: Hysterectomy prevalence estimates are derived from cross-sectional data using a life table method. Analysis is based on hysterectomy data from the Utah Hospital Discharge Data Base and cancer cases recorded by the Utah Cancer Registry, 1995-1997.RESULTS: Correction for hysterectomy prevalence increases cancer incidence rates, more so at older ages, such that by ages 85 and older the increase is 92% for uterine cancers of the cervix and corpus, and 17% for ovarian cancer. Over the life span, correction for hysterectomy prevalence increases the estimated number per 100,000 developing these diseases by 195 (from 603 to 798) for uterine cervical cancer, 1,553 (from 2,580 to 4,133) for corpus uterine cancer, and 911 (1,674 to 2,585) for ovarian cancer.CONCLUSIONS: The utility of the cross-sectional method for deriving hysterectomy prevalence is that it does not require several years of data to obtain reasonable estimates. Correction for hysterectomy prevalence has a large effect on the cancer rates and probabilities, providing a more accurate representation of the risk and burden of these cancers.

Journal Article↗

PubMed2002

Incidence of major depression: prediction from subthreshold categories in the Stirling County Study.

BACKGROUND: Validity of the newly-proposed categories of Minor Depression (MinD) and Subsyndromal Depression (SSD) would be strengthened if they were found to be related to the incidence of Major Depressive Episode (MDE). In this report, the subsequent incidence of MDE was assessed in terms of baseline evidence about the two subthreshold categories and Dysthymic Disorder (DysD). METHODS: The Diagnostic Interview Schedule was used to interview 489 subjects twice between 1991 and 1995 as part of the Stirling County Study. Life table methods were used to calculate incidence rates and log linear analysis was employed for statistical assessment. RESULTS: The average annual incidence of MDE was 10 per 1000. The rates associated with the baseline categories were 210 per 1000 for DysD, 21 for MinD; 13 for SSD; and four for the remainder of subjects who constituted the reference group. Only the incidence related to DysD was significantly higher than that for the reference group. Comparing Time 1 and Time 2, one-third of the subjects gained or lost symptoms and the comorbidity of MDE and DysD increased. LIMITATIONS: The study population was, on average, 63 years of age. Older age and the small size of the cohort may have influenced the findings. Another limitation may relate to the use of lifetime rather than current symptomatology. CONCLUSIONS: DysD is strongly associated with MDE suggesting that the chronic and episodic forms of unipolar depression constitute one disorder. The other subthreshold categories should be further investigated in terms of prodromal qualities. The persistence of dysphoria, as in DysD, may be a more important feature of the depression prodrome than the number of symptoms.

Adult↗

PubMed2002

Patient-related and centre-related factors influencing technique survival of peritoneal dialysis in The Netherlands.

BACKGROUND: Although technique failure occurs relatively frequently in peritoneal dialysis (PD), few data have been published on differences in technique failure between centres. METHODS: Using data from RENINE, the comprehensive dialysis registry of The Netherlands, we analysed PD technique failure rates in the period 1994-1999, with life table methods and Cox multiple regression analysis. Patient age, sex, and the presence or absence of diabetes were included in the analysis, as well as time of initiation of PD and the following centre characteristics: number of PD patients treated in the centre and percentage of patients on PD. RESULTS: Technique failure was higher in older patients: 2-year technique survival was 75% in those younger than 45 years, 68% in the group aged 45-64 years, and 60% in those over 64 years (P<0.0001). Sex and diabetes made no difference in technique survival. Mean annual technique failure rates varied greatly between centres (10-59%) and correlated with the number of patients on PD in the centre (r=-0.396, P=0.009) and with the fraction of patients on PD (r=-0.410, P=0.006). Low technique survival rates occurred mainly in centres with less than 20 patients on PD: relative risk for technique failure 1.68 as compared with larger centres. Patients starting PD in the period 1997-1999 had better technique survival than those starting in 1994-1996 (P=0.001). CONCLUSION: PD technique survival in The Netherlands has increased in recent years. Having less than 20 PD patients in a centre or having a small fraction of patients on PD carries an increased risk of technique failure. The variability in PD technique survival between centres indicates that in many centres further improvements should be possible.

Diabetic Nephropathies↗

PubMed1987

Extension of life-table methodology to allow for left-censoring in survival studies of pacing devices followed by commercial monitoring services.

The actuarial life-table is commonly used to describe lifetime data of living subjects and manufactured products. The life-table method allows subjects to come under observation at different times and, thus, to have differing lengths of follow-up, by assuming all subjects begin their lifetimes relative to the outcome of interest at some common point in time. As time progresses, subjects are withdrawn from the life-table when their period of observation has elapsed. This pattern of follow-up is often termed "right-censoring." An important feature of the classical life table approach is that the time at which the subject is placed at risk is known, and the status relative to the outcome of interest is known for the entire time at risk. Sometimes, however, subjects cannot be observed for some period after the beginning of their lifetimes. The example to be considered involves follow-up data collected by a commercial pacemaker monitoring service, to which patients subscribe, generally at some point following the actual implant of the pacemaker. Since the outcome of interest is device failure after implant, some means of dealing with the lack of information between implant and initiation of follow-up is needed. The extension of the actuarial life-table to accommodate this "left-censoring" will be described in this paper.

Actuarial Analysis↗

PubMed2000

Abnormalities of chromosome bands 13q12 to 13q14 in childhood acute lymphoblastic leukemia.

PURPOSE: Little is known about nonrandom deletions of chromosome bands 13q12 to 13q14 (13q12-14) in acute lymphoblastic leukemia (ALL). We determined the prognostic significance of cytogenetically identified breakpoints in 13q12-14 in children with newly diagnosed ALL treated on Children's Cancer Group protocols from 1988 to 1995. PATIENTS AND METHODS: Breakpoints in 13q12-14 were identified in 36 (2%) of the 1,946 cases with accepted cytogenetic data. Outcome analysis used standard life-table methods. RESULTS: Seventeen patients (47%) with an abnormal 13q12-14 were classified, according to the National Cancer Institute (NCI), as poor risk, and 15 patients (42%) were standard risk; four (11%) were infants less than 12 months of age. Eight cases had balanced rearrangements of 13q12-14, 27 patients had a partial loss of 13q, and one had both a partial gain and a partial loss. The most frequent additional abnormalities among these patients were an abnormal 12p, a del(6q), a del(9p), a 14q11 breakpoint, and an 11q23 breakpoint. Nineteen patients were pseudodiploid, 10 were hyperdiploid, and seven were hypodiploid. Patients with an abnormal 13q12-14 had significantly worse event-free survival than patients lacking such an abnormality, with estimates at 6 years of 61% (SD = 14%) and 74% (SD = 1%), respectively (P =.04; relative risk = 1.74). Overall survival, however, was similar for the two groups (P =.25). The prognostic effect of an abnormal 13q was attenuated in a multivariate analysis adjusted for NCI risk status and ploidy (P =.72). CONCLUSION: Aberrations of 13q12-14 may contribute to leukemogenesis of childhood ALL and confer increased risk of treatment failure but are associated with other poor-risk features.

Child↗

PubMed1999

[Study of recurrence and metastasis after radical resection of carcinoma of the lung].

OBJECTIVE: To study the characteristics of recurrence and metastasis following radical resection of carcinoma of the lung. METHODS: A total of 1,229 cases of radically resected lung cancer was statistically analyzed using STATA software. The survival rate was estimated using life table method. Comparisons of survival in each group were made according to the log rank test. The differences in rate between groups was assessed by chi 2 test. RESULTS: Recurrence rate was found higher in squamous-cell carcinoma than in adenocarcinoma. It was also higher in sleeve resection and partial resection than in other resection modes (P < 0.05). The rate of lymph node metastasis was higher in adenocarcinomas than in squamous-cell carcinoma (P < 0.05). Lung, bone, brain, liver, subcutis, and adrenal glands were the common resorts of metastasis, in decreasing order of frequency. Metastatic rate was the lowest in squamous-cell carcinoma. Active therapy can still improve the survival even when recurrence and metastasis occurred. CONCLUSION: It is recommended to avoid partial resection for the invaded adjacent lobe whenever patient's condition can stand multilobectomy. It is necessary to assure resection margin length when sleeve resection is performed in order to reduce recurrence. Active therapy can improve survival of patients with recurrence and metastasis.

Adenocarcinoma↗

PubMed1996

Prospective comparison of infrainguinal bypass grafting in patients with and without antiphospholipid antibodies.

PURPOSE: The antiphospholipid antibodies (APL)-anticardiolipin antibodies (ACL) and lupus anticoagulant (LA)-are widely believed to be associated with decreased lower extremity bypass graft patency rates. To date, no prospective cohort study has confirmed this assumption. A prospective comparison of the result of infrainguinal revascularization procedures performed since 1990 in patients with and without APL forms the basis of this report. METHODS: Patients who underwent elective infrainguinal bypass procedures from 1990 to 1994 were evaluated for hypercoagulable states (ACL, LA, protein C, protein S, and antithrombin III). Patient data were prospectively entered in a computerized vascular registry, and postoperative follow-up was maintained for life. Graft patency, limb salvage, and patient survival rates were calculated by life-table methods. RESULTS: Three hundred twenty-seven lower extremity bypass grafting procedures were performed in 262 patients. APLs were present in 83 patients (32%); 70 patients (84%) had ACLs only, 11 patients (13%) had LA only, and two patients (3%) had both ACLs and LA. There was no significant difference between APL-positive and APL-negative patients with respect to demographics, associated medical conditions, indication for operations, and type of procedures performed. More patients who had APLs had warfarin treatment after surgery (43% vs 24%, p = 0.002). Life table 4-year primary patency rates showed minimal difference (APL-positive, 43%; APL-negative, 59%; p = 0.087), and no significant difference was noted in assisted primary patency rates (APL positive, 72%; APL negative, 73%; p = NS), limb salvage rates (APL positive, 79%; APL negative, 88%; p = NS), and patient survival rates (APL positive, 67%; APL negative, 66%; p = NS). CONCLUSIONS: APLs were found in a surprising one third of the patients who underwent leg bypass grafting procedures. The majority of APLs identified were ACLs (87%). There was minimal difference in graft primary patency rates, and no difference in assisted primary patency, limb salvage, and survival rates between patients with and without APLs who underwent leg bypass grafting procedures. The extreme morbidity rate associated with APLs in previous reports is not confirmed by this prospective study. APLs should not be regarded as a contraindication to indicated leg bypass grafting procedures.

Aged↗