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Results for “Life Table Method”

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PubMed1996

Familial aggregation of type 2 (non-insulin-dependent) diabetes mellitus in south India; absence of excess maternal transmission.

The family histories of 976 South Indian Type 2 diabetic patients were recorded in a questionnaire-based survey to establish whether the excess maternal transmission of Type 2 diabetes reported in low prevalence Europid populations was also evident in this medium prevalence population. In 450 families (46.1%), no parental history of diabetes was reported. In 423 families with one parent diabetic, 222 fathers (52.5%) and 201 (47.5%) mothers were diabetic. In the remaining 103 (10.6%) families, both parents were diabetic. In contrast to previous studies, we found no evidence for substantial maternal excess in the transmission of diabetes (325 diabetic fathers vs 304 mothers; p = 0.4; p = 0.07 when compared using life table methods). The age of diagnosis of diabetes in probands was lower than that of their diabetic parents (p < 0.001): furthermore increasing parental history of diabetes was associated with an earlier diagnosis of diabetes in probands (p < 0.001). These results emphasize the extensive familial aggregation of Type 2 diabetes in this population but fail to replicate the evidence for excess maternal transmission evident in lower prevalence Europid populations, suggesting ethnic differences in the extent of this phenomenon.

Adult↗

PubMed1991

Recurrence rates of treated basal cell carcinomas. Part 2: Curettage-electrodesiccation.

This is the second article in a series that reviews the experience in the Skin and Cancer Unit, from 1955 through 1982, with the treatment of basal cell carcinomas (BCCs). This report deals with 2314 previously untreated (primary) BCCs removed by curettage-electrodesiccation. Multivariate analysis showed that increasing lesion diameter (P less than .001), high-risk anatomic sites (nose, paranasal, nasal-labial groove, ear, chin, mandibular, peri-oral, and peri-ocular areas) (P less than .001), middle-risk anatomical sites (scalp, forehead, pre- and post-auricular, and malar areas) (P less than .001), and time-span treated (1955 to 1963) (P = .012) were independent risk factors for high recurrence rates. The patient's age, sex, and lesion duration before treatment did not affect the recurrence rates. In order to best illustrate our current experience with BCCs, the last time-span (1973 to 1982) was examined in detail. For the low-risk sites (neck, trunk, and four extremities), BCCs of all diameters responded well to curettage-electrodesiccation with an overall 5-year recurrence rate of 3.3% (SE = 1.5%) determined by the modified life-table method. In the middle-risk sites BCCs less than 10 mm in diameter had a recurrence rate of 5.3% (SE = 2.7%). Finally, in the high-risk sites, lesions less than 6 mm in diameter had a recurrence rate of 4.5% (SE = 2.6%). Thus, BCCs less than 6 mm in diameter, regardless of anatomic site, as well as selected larger BCCs depending on their anatomic site, are effectively treated by currettage-electrodesiccation.

Adult↗

PubMed1999

Survival following enucleation versus plaque radiotherapy in statistically matched subgroups of patients with choroidal melanomas: results in patients treated between 1980 and 1987.

BACKGROUND: The relative effectiveness of plaque radiotherapy and enucleation in patients with choroidal or ciliochoroidal melanoma remains controversial. Most published comparative survival studies have evaluated clearly biased groups, short-term follow-up, or both. METHODS: The authors performed a retrospective, non-randomized, comparative survival study on 734 patients with a choroidal or ciliochoroidal melanoma treated by enucleation (n=237) or plaque radiotherapy (n=497) between July 1980 and June 1985, and on a residual group of 448 patients, 103 treated by enucleation and 345 treated by plaque radiotherapy, identified by variable-by-variable range matching. Melanoma-specific mortality and all-cause mortality were evaluated by the life-table method. RESULTS: The melanoma-specific mortality rate was substantially worse in the original enucleation subgroup throughout available post-treatment follow-up; however, differences in baseline prognostic factors between the subgroups are likely to explain much of the survival differential. After eliminating patients with nonoverlapping values of individual clinical variables to adjust for recognized intergroup differences at baseline, there was no significant difference in the mortality curves of the residual subgroups. The cumulative 15-year survival based on deaths from metastatic melanoma in the enucleation subgroup was 57.1% (standard error=6.4%), while that in the plaque radiotherapy subgroup was 61.8% (standard error=3.3%). CONCLUSION: On the basis of these results, we conclude that a large difference in survival between equivalent groups of patients with primary choroidal or ciliary body melanoma treated by enucleation or by plaque radiotherapy appears unlikely.

Adult↗

PubMed1991

Postoperative radiation therapy does not increase survival after curative resection for squamous cell carcinoma of the middle and lower esophagus as shown by a multicenter controlled trial. French University Association for Surgical Research.

In 1978, postoperative radiation therapy was suggested to be an additive treatment of carcinoma of the esophagus. In 1987, we began a multicenter trial of patients with epidermoid carcinoma of the middle third or the lower third of the esophagus. Isolated surgical treatment (119 patients) was compared with surgical treatment followed by radiation therapy (102 patients). Randomization was performed according to the results of pathologic examination of all resected lymph nodes. Patients were divided into three groups: N0, no lymph node invasion; N+1, invasion of paraesophageal lymph nodes, and N+2, invasion of distal lymph nodes (recurrent, tracheal and celiac). All patients included in this trial had a curative esophageal resection. In the group receiving radiation therapy (102 patients), a total dose of 45 to 55 Grays was delivered in the mediastinal, right and left supraclavicular areas and also to the celiac area when celiac lymph node invasion was present. Two hundred and twenty-one patients were randomized and observed from three to nine years; life table method (log rank method) was used to compare survival and local recurrence. In all patients studied, the survival rate was significantly higher (p less than 0.01) in patients without lymph node invasion (group N0) than in patients with lymph node invasion (groups N+1 and N+2). Postoperative radiation therapy did not improve survival in any group. This lack of improvement in survival was present regardless of lymph node status. However, there were significantly fewer recurrences in patients receiving radiation therapy as compared with those not receiving radiation therapy.

Carcinoma, Squamous Cell↗

PubMed1999

Superficial femoral eversion endarterectomy combined with a vein segment as a composite artery-vein bypass graft for infrainguinal arterial reconstruction.

OBJECTIVE: The purpose of this study was to determine the results of composite artery-vein bypass grafting for infrainguinal arterial reconstruction. METHODS: This study was designed as a retrospective case series in two tertiary referral centers. Forty-eight of 51 patients underwent the procedure of interest for the treatment of ischemic skin lesions (n = 42), rest pain (n = 3), disabling claudication (n = 1), and infected prosthesis (n = 2). The intervention used was infrainguinal composite artery-vein bypass grafting to popliteal (n = 18) and infrapopliteal (n = 30) arteries, with an occluded segment of the superficial femoral artery prepared with eversion endarterectomy and an autogenous vein conduit harvested from greater saphenous veins (n = 43), arm veins (n = 3), and lesser saphenous veins (n = 2). The main outcome measures, primary graft patency rates, foot salvage rates, and patient survival rates, were described by means of the life-table method for a mean follow-up time of 15.5 months. RESULTS: The cumulative loss during the follow-up period was 6% and 24% at 6 and 12 months, respectively. The primary graft patency rates, the foot salvage rates, and the patient survival rates for patients with popliteal grafts were 60.0% +/- 9.07%, 75.7% +/- 9.18%, and 93.5% +/- 6.03%, respectively, at 1 month; 53.7% +/- 11.85%, 68.9% +/- 12.47%, and 85. 0% +/- 9.92% at 1 year; and 46.7% +/- 18.19%, 68.9% +/- 20.54%, and 53.1% +/- 17.15% at 5 years. For infrapopliteal grafts, the corresponding estimates were 72.4% +/- 7.06%, 72.9% +/- 6.99%, and 92.7% +/- 4.79% at 1 month; 55.6% +/- 10.70%, 55.4% +/- 10.07%, and 77.9% +/- 9.02% at 1 year; and 33.6% +/- 22.36%, 55.4% +/- 30.20%, and 20.8% +/- 9.89% at 5 years. CONCLUSION: The composite artery-vein bypass graft is a useful autogenous alternative for infrainguinal arterial reconstruction when a vein of the required quality is not available or when the procedure needs to be confined to the affected limb.

Aged↗

PubMed1983

Long-term prognosis after recovery from myocardial infarction: a nine year follow-up of the Perth Coronary Register.

Patients registered by the 1971 Perth Coronary Register as having suffered a myocardial infarction were followed up for 9 years. The Register was a community-based study that used standard methods and criteria as part of a World Health Organization collaborative investigation. Of the 1078 patients studied, 77% survived the first 24 hr and 62% the first 28 days; 0.3% were lost to follow-up. For the 666 patients alive at 28 days, the crude 1, 5, and 9 year survival rates were 88%, 67%, and 52%, respectively. The relationship between 54 variables and the survival of patients alive 28 days after myocardial infarction was examined by life-table methods and the log rank test, and then by fitting a proportional hazards model to the data. The important prognostic factors were age, sex, past history of myocardial infarction, stroke, diabetes and hypertension, tachycardia at presentation, hypotension at presentation, and the occurrence of arrhythmias as short-term complications. The most appropriate mathematical description of the joint effects of the prognostic factors was a multiplicative model with no interaction.

Adult↗

PubMed1993

Predicting the course of disease.

The ability to predict the course of disease and the effect of interventions is critical to effective medical practice and health care management. In this analysis, we sought to test whether available clinical data and analytic methodologies can be used to accurately predict the time course of the probability of death after hospital admission and the probability of readmission following discharge for patients with acute myocardial infarction or pulmonary disease. We grouped patients by selected physiologic characteristics and made time-to-event predictions using multiple regression models. These predictions were compared with observed probabilities calculated using the actuarial or life-table method. Predictions made with the Bailey-Makeham model generally replicated observed experience. They accurately accounted for substantial differences in the patterns of death and readmission and accurately delineated the effects of therapies, after adjustment for patient risk. These results were validated by analyses of resampled populations that differed in case mix from the source population. We believe that using such models to project the course of disease and the effects of treatment on that course in defined classes of patients should facilitate the development of practice guidelines for patient care and the management of health care resources.

Disease↗

PubMed2002

Results of iliac artery stent placement in patients younger than 50 years of age.

PURPOSE: To determine long-term outcome in patients 50 years of age or younger treated with iliac artery stent placement. MATERIALS AND METHODS: The records of 412 patients who underwent iliac artery stent placement during a 62-month study period were reviewed retrospectively. Forty-two patients younger than age 50 (mean age = 45 y) at the time of stent placement were included in the study population. Presenting symptoms included claudication (47%), rest pain (17%), ulceration/tissue loss (31%), and blue toe syndrome (5%). Anatomic, hemodynamic, and clinical success rates of the stent placement procedure were assessed. Stent patency rates were calculated by life-table methods. RESULTS: Fifty-nine iliac lesions were treated with stents; 62% of patients underwent treatment of a single lesion whereas 38% had multiple lesions treated. Thirty-one percent were treated after a failed angioplasty procedure and 69% were treated with stent placement primarily. After stent placement, 34 patients (82%) experienced symptomatic relief, although eight of these patients (19%) underwent a planned ipsilateral infrainguinal bypass procedure during the same hospitalization. During follow-up, five patients (12%) required a bypass procedure as a result of stent failure and two patients (5%) required below-knee amputation. Seven patients (17%) required endovascular stent revision, with none requiring additional surgery. At 1, 2, and 3 years, the primary patency rates were 86%, 72%, and 65%, and the secondary patency rates were 90%, 88%, and 88%, respectively. CONCLUSIONS: Iliac stent placement successfully addresses the presenting symptoms of young patients with peripheral vascular disease and results in patency rates that are similar to those reported in a more general population. With appropriate postprocedural surveillance, restenosis can be addressed in many patients with use of endovascular techniques, limiting the need for surgical revision.

Adult↗

PubMed1994

Progestogen-only contraceptives during lactation: II. Infant development. World Health Organization, Task Force for Epidemiological Research on Reproductive Health; Special Programme of Research, Development, and Research Training in Human Reproduction.

Growth, development and health of infants whose mothers used progestogen-only contraceptives during lactation were examined in a prospective, non-randomized study that was carried out in seven centres in five countries (Egypt, Thailand, Kenya, Chile and Hungary). The results on development are reported here. Breastfeeding women requesting effective contraception were admitted to the study at six weeks postpartum. Infants of acceptors of progestogen-only methods (pill, DMPA, NET-EN or NORPLANT implants) and non-hormonal methods (IUD, barrier methods or sterilization) formed the study groups. The follow-up was at monthly intervals until the end of the first postpartum year. At each visit, the infant examination included, among other things, a set of developmental tests covering the following areas: gross motor, vision and fine motor, hearing, language and concept development, and self help and social skills. Participating in the study were 2466 mother-infant pairs. The comparisons between the study groups were carried out within centres using life table methods and Cox-model analysis having the time to first passing the test as the criterion. There were altogether 247 comparisons between the study groups. Thirty-two (13%) of these comparisons showed statistically significant differences: 20 differences showed that the infants in the progestogen-only groups passed the tests at an earlier age and 12 at a later age than infants in the non-hormonal groups. Since no consistent trends were observed across the centres, we conclude that in this study the progestogen-only contraceptives used during lactation did not adversely affect infant development.

Adolescent↗

PubMed1993

A multicenter study of the clinical performance of the Ortho Gyne-T380 Slimline intrauterine device in routine use in general practice and family planning clinics. UK Family Planning Research Network.

In a multiclinic use-effectiveness study, 505 parous women were fitted with an Ortho Gyne-T380 Slimline intrauterine device (IUD). Gross cumulative event rates, calculated by the Tietze-Potter life-table method, show the device to have a very low pregnancy rate and a low expulsion rate. The rate of removal following complaints of bleeding and/or pain was high. The incidence of infection was low and more likely to occur among younger users. The older parous women were more likely to have a satisfactory experience of IUD use than younger users. In accordance with current advice, and following a full discussion with the client, long-term use of the device beyond the manufacturer's recommended time period will continue among satisfied users.

Adult↗

PubMed1998

[A randomized control clinical trial of glaucoma filtering surgery with homoharringtonine].

OBJECTIVE: To study the antiproliferative effects of homoharringtonine (Hh) on glaucoma filtering surgery. METHODS: In a randomized control clinical trial, 78 patients (88 eyes) with refractory glaucoma underwent trabeculectomy with and without Hh. In the Hh-treated eyes (n = 46), the therapeutic dose of Hh was: intraoperative application of Hh 0.4 mg and postoperative subconjunctival injections of Hh 0.62 +/- 0.20 mg (ranged 0.53 - 0.75 mg). In the control eyes (n = 42), Hh was not used. The follow-up period was 18 to 48 months, and the data were analyzed by using the life-table method of Kaplan-Meier. RESULTS: The cumulative success probability in Hh group was 84.5% and that in control group was 50.9%, the difference being significant (P < 0.05). The cumulative percentage of functioning bleb in Hh group was 84.2% and that in control group was 52.9% (P < 0.05). The rates of corneal erosion were 23.9% and 7.1%, and the rates of conjunctival wound leak were 6.5% and 2.4% in Hh and control group respectively. There was no significant change in corneal endothelial density following the use of Hh (P > 0.05). CONCLUSION: The study indicates that Hh is a safe and effective antiproliferative agent for the use in glaucoma filtering surgery, it not only can increase the success probability considerably, but also maintain at least the postoperative IOP at relatively low normal level for 3 years.

Adult↗

PubMed1991

Carotid endarterectomy for asymptomatic carotid stenosis: a ten-year experience with 120 procedures in a fellowship training program.

Performance of carotid endarterectomy for asymptomatic carotid stenosis has been restricted during recent years because of concern of reported complications in as high as 10-15% of patients, as well as limited long-term data on stroke protection. During the last 10 years, we have studied immediate and long-term results of carotid endarterectomy for asymptomatic disease in 120 patients. Operations were performed by a clinical vascular fellow with a staff surgeon in attendance in 113 (94%) cases with the remainder performed by the staff surgeon. Patients' mean age was 66 years; 82% were men. Risk factors included hypertension (56%), smoking (52%), coronary artery disease (32%), diabetes (24%), and hypercholesterolemia (6%). Arteriographic severity of stenoses was 80-99% in 74%, 60-79% in 22%, and 40-59% in 4% of cases. Postoperative complications included two transient neurological events (1.7%). No permanent strokes or deaths occurred. Using the life table method, cumulative stroke rate was 4.5% for ipsilateral events and 7.3% for contralateral events, confirming the high degree of stroke protection afforded by carotid endarterectomy in this population. Since these results were accomplished in a fellowship training program, we regard adequacy of this experience as the most influential factor in accomplishing this record. Surgeons who are unable to achieve comparable results should consider abandonment of the procedure or an extended period of additional training.

Aged↗

PubMed2005

Frequency and predictors of inappropriate management of recurrent gout attacks in a longitudinal study.

OBJECTIVE: To evaluate the patterns and determinants of medication use during recurrent gout attacks. METHODS: We followed participants with documented gout in an online prospective case-crossover study. During an attack, subjects were asked if they had consulted a physician for the attack and what medications they were using. Definitely inappropriate therapy was defined as use of allopurinol or a uricosuric agent acutely without having used it as a prophylactic. Potentially inappropriate therapy was defined as use of analgesics alone, alternative remedies, or no medications. We estimated the risk of having >or= 1 attack in 1 year using life table methods. We examined the relation of various risk factors to the risk of inappropriate therapy using Poisson regression. RESULTS: Among 232 participants (mean age 52 yrs, 81% male) with documented gout, the risk of having >or= 1 attack in a year was 69%. One hundred ten participants consulted a physician for each attack, 49 did so for only some attacks, while 43 never consulted a physician for any attack. Fifty-three participants had definitely (n = 10) or potentially (n = 43) inappropriate therapy for their recurrent attacks. Physician consultation for an attack was associated with increased risk of inappropriate therapy (risk ratio, RR, 2.5, p = 0.006), whereas an increasing number of gout attacks was associated with lower risk of inappropriate therapy (RR 0.8, p = 0.01). CONCLUSION: Given the high risk of recurrent attacks and the substantial number of persons whose attacks are not appropriately managed, further education about management of gout attacks for both patients and physicians may be warranted.

Adult↗

PubMed1997

Incisional hernia recurrence following "vest-over-pants" or vertical Mayo repair of primary hernias of the midline.

A series of 68 primary midline incisional hernias with a vertical Mayo repair was evaluated retrospectively. Patients without documented hernia recurrence following this repair were invited for physical examination. Life-table methods were used for statistical analysis. The 1-, 3-, 5-, and 10-year cumulative recurrence rates were 35%, 46%, 48%, and 54%, respectively. Also, generally accepted risk factors were studied. Multivariate analysis identified the size of the hernia (p = 0.02) and the use of steroids (p = 0.04) as the most important independent risk factors of first time recurrent incisional hernia. Considering the high recurrence rates found, the results of this study strongly suggest that the vest-over-pants repair should no longer be used for closure of midline incisional hernias.

Adult↗

PubMed1991

[Compliance with tuberculosis treatment in adults in Santiago, Chile].

A prospective study was conducted to estimate the current magnitude of adherence to short-course tuberculosis treatment, the degree of abandonment, the characteristics of treatment dropouts, and the causes of this abandonment. The study group was made up of tuberculosis patients over the age of 15 who received care at the Western and Southern Health Services of the Metropolitan Region of Santiago, Chile, between 1 October 1987 and 31 January 1988. The percentage abandoning treatment, calculated by the life table method, was 11.5. The profile of patients who dropped out of treatment was as follows: male, under 45 years of age, single, low level of education, no steady work, homeless, and alcoholic. In addition, an opinion survey on the variables associated with abandonment was conducted and it was concluded that the main ones were alcoholism and intolerance to tuberculosis drugs. Awareness of this profile makes it possible to take measures to prevent patients from abandoning treatment, as well as to educate and even hospitalize at the start of treatment those tuberculous patients exhibiting such a profile.

Adolescent↗

PubMed1999

Impaired glucose tolerance is a risk factor for cardiovascular disease, but not impaired fasting glucose. The Funagata Diabetes Study.

OBJECTIVE: To determine whether the new category of impaired fasting glucose (IFG) recently proposed by the Expert Committee of the American Diabetes Association is a risk factor for cardiovascular disease. RESEARCH DESIGN AND METHODS: Death certificates and residence transfer documents from the cohort population consisting of participants of the diabetes prevalence study in Funagata, Yamagata prefecture, Japan, 1990-1992, were analyzed up through the end of 1996. First, the cohort population was classified into three groups: normal glucose tolerance (NGT) (n = 2,016), impaired glucose tolerance (IGT) (n = 382), and diabetic (n = 253). Then the same population was reclassified into normal fasting glucose (NFG), IFG, and diabetic. The cumulative survival rates among the groups were compared using the classical life-table method, and age-adjusted analyses, the person-year method, and Cox's proportional hazard model were adopted. RESULTS: At the end of seven observed years, the cumulative survival rates from cardiovascular disease of IGT and diabetes were 0.962 and 0.954, respectively, both significantly lower than that of NGT (0.988). The Cox's proportional hazard model analysis showed that the hazard ratio of IGT to NGT on death from cardiovascular disease was 2.219 (95% CI 1.076-4.577). However, the cumulative survival rate of IFG from cardiovascular disease was 0.977, not significantly lower than that of NFG (0.985). The Cox's hazard ratio of IFG to NFG on death from cardiovascular disease was 1.136 (0.345-3.734), which was not significant either. CONCLUSIONS: IGT was a risk factor for cardiovascular disease, but IFG was not.

Aged↗

PubMed2003

Stripping operation with sclerotherapy for primary varicose veins due to greater saphenous vein reflux: three-year results.

The purpose of this study was to compare the recurrence-free rates of stripping with varicectomy and stripping with sclerotherapy for the treatment of primary varicose veins due to greater saphenous vein insufficiency. This is a multicenter retrospective analysis of 186 patients and 220 limbs treated for primary varicose veins due to greater saphenous vein reflux from January 1996 to December 1997. The difference between the two groups was evaluated by the Chi(2) test or t-test. The recurrence-free rates were estimated by the Kaplan-Meier life-table method. The mean follow-up period was 3.2 +/- 1.1 years. The clinical backgrounds of patients with varicectomy stripping and sclerotherapy stripping were not significantly different between the two groups. The overall recurrence-free rates at 1 and 3 years were 97.0% and 91.4%, respectively. The recurrence-free rates at 3 years were 93.5% for stripping with varicectomy and 88.6% for stripping with sclerotherapy. No statistical difference was found between the two groups. The recurrence rate after stripping with sclerotherapy was equivalent to that after stripping with varicectomy. Thus concurrent varicectomy can be replaced with sclerotherapy.

Aged↗

PubMed1995

Net effect of oral contraceptive use on the risk of cancer in women in the United States.

OBJECTIVE: To estimate by meta-analysis the risk of developing cancer of the breast, uterine cervix, endometrium, ovary, and liver from age 20-54 years in the United States in women using oral contraceptives (OCs) for 4, 8, or 12 years. DATA SOURCES: Using pairs of terms (such as oral contraception and breast neoplasms), I searched for English-language literature on OC use and cancer published since 1980 and cited through July 1994 in the MEDLINE data base. METHODS OF STUDY SELECTION: I analyzed all epidemiologic studies reporting estimates of relative risk (RR) by duration and recency of OC use (79 independent studies in total). DATA EXTRACTION AND SYNTHESIS: Reported duration-specific and recency-specific estimates of RR, with the corresponding numbers of cases and controls or person-time at risk for cohort studies, were abstracted from each article. Relative risk of cancer as a function of both duration and recency of OC use was then estimated by weighted regression and applied, using life-table methods, to United States population-based data on age-specific mortality and cancer incidence. CONCLUSIONS: For every 100,000 women in the United States who never use OCs, the number developing cancer from age 20-54 years is estimated to be 2782 (breast), 425 (cervix), 438 (endometrium), 369 (ovary), and 20 (liver). For women using OCs for 8 years, the estimated number of additional or fewer cases per 100,000 users is +151 (breast), +125 (cervix), -197 (endometrium), -193 (ovary), and +41 (liver). Therefore, from a population perspective, there are only small cancer-related risks and benefits associated with OC use and, on balance, the net effect is negligible.

Adult↗