scholarly journals Understanding bias when estimating life expectancy from age at death: A simulation approach applied to Morquio Syndrome A

Author(s):  
Xue Yin ◽  
Jaeil Ahn ◽  
Simina M. Boca

BackgroundLife expectancy can be estimated accurately from a cohort of individuals born in the same year and followed from birth to death. Due to the difficult and time-consuming nature of following a cohort prospectively, life expectancy is often assessed based on death data, which may lead to potentially biased estimates. This is more likely to be a problem in rare diseases such as Morquio syndrome A.MethodTo investigate how accurate the estimation of life expectancy is using death data, we simulate the survival of individuals with Morquio syndrome A under four different survival scenarios. In each scenario, we estimate the mean and median survival times within a defined period and compare them with the true life expectancy.ResultsWhen life expectancy is constant during the entire period, using death data does not result in a biased estimate of life expectancy. However, when life expectancy increases during the follow-up period, using only death data leads to a substantial underestimation of life expectancy.ConclusionLife expectancy can change over time, along with changes in the environment and/or biomedical innovation. When the life expectancy is increasing — as is often expected to be the case in rare diseases — estimating it based on contemporary death data will result in a downward bias. Therefore, it is crucial to understand how estimates of life expectancy are obtained and to interpret them in an appropriate context, and to assess estimation methods within a sensitivity analysis framework, similar to the simulations performed herein.

2022 ◽  
Vol 15 (1) ◽  
Author(s):  
Xue Yin ◽  
Jaeil Ahn ◽  
Simina M. Boca

Abstract Objective Life expectancy can be estimated accurately from a cohort of individuals born in the same year and followed from birth to death. However, due to the resource-consuming nature of following a cohort prospectively, life expectancy is often assessed based upon retrospective death record reviews. This conventional approach may lead to potentially biased estimates, in particular when estimating life expectancy of rare diseases such as Morquio syndrome A. We investigated the accuracy of life expectancy estimation using death records by simulating the survival of individuals with Morquio syndrome A under four different scenarios. Results When life expectancy was constant during the entire period, using death data did not result in a biased estimate. However, when life expectancy increased over time, as is often expected to be the case in rare diseases, using only death data led to a substantial underestimation of life expectancy. We emphasize that it is therefore crucial to understand how estimates of life expectancy are obtained, to interpret them in an appropriate context, and to assess estimation methods within a sensitivity analysis framework, similar to the simulations performed herein.


2019 ◽  
Vol 31 (12) ◽  
pp. 1781-1789 ◽  
Author(s):  
Adrie A.J. Gerritsen ◽  
Christian Bakker ◽  
Frans R.J. Verhey ◽  
Yolande A.L. Pijnenburg ◽  
Joany K. Millenaar ◽  
...  

ABSTRACTObjectives:The aim of this study was to investigate survival time and life-expectancy in people with young-onset dementia (YOD) and to examine the relationship with age, sex, dementia subtype and comorbidity.Design, Setting and Participants:Survival was examined in 198 participants in the Needs in Young-onset Dementia study, including participants with Alzheimer’s dementia (AD), vascular dementia (VaD) and frontotemporal dementia (FTD).Measures:The primary outcomes were survival time after symptom onset and after date of diagnosis. Cox proportional hazards models were used to explore the relationship between survival and age, sex, dementia subtype and comorbidity. Additionally, the impact on remaining life expectancy was explored.Results:During the six-year follow-up, 77 of the participants died (38.9%), 78 participants survived (39.4%) and 43 were lost to follow-up (21.7%). The mean survival time after symptom onset and diagnosis was 209 months (95% CI 185-233) and 120 months (95% CI 110-130) respectively. Participants with AD had a statistically significant shorter survival compared with VaD participants, both regarding survival after symptom onset (p = 0.047) as well as regarding survival after diagnosis (p = 0.049). Younger age at symptom onset or at diagnosis was associated with longer survival times. The remaining life expectancy, after diagnosis, was reduced with 51% for males and 59% for females compared to the life expectancy of the general population in the same age groups.Conclusion/Implications:It is important to consider the dementia subtype when persons with YOD and their families are informed about the prognosis of survival. Our study suggests longer survival times compared to other studies on YOD, and survival is prolonged compared to studies on LOD. Younger age at symptom onset or at diagnosis was positively related to survival but diagnosis at younger ages, nevertheless, still diminishes life expectancy dramatically.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
D Lauritzen ◽  
H.J Vodstrup ◽  
T.D Christensen ◽  
M Onat ◽  
R Christensen ◽  
...  

Abstract Background Following catheter ablation for atrial fibrillation (AF), CHADS2 and CHA2DS2-VASc have utility in predicting long-term outcomes. However, it is currently unknown if the same holds for patients undergoing surgical ablation. Purpose To determine whether CHADS2 and CHA2DS2-VASc predict long-term outcomes after surgical ablation in concomitance with other cardiac surgery. Methods In this prospective, follow-up study, we included patients who underwent biatrial ablation - or pulmonary vein isolation procedure concomitantly with other cardiac surgery between 2004 and 2018. CHADS2 and CHA2DS2-VASc scores were assessed prior to surgery and categorized in groups as 0–1, 2–4 or ≥5. Outcomes were death, AF, and AF-related death. Follow-up was ended in April 2019. Results A total of 587 patients with a mean age of 68.7±0.4 years were included. Both CHADS2 and CHA2DS2-VASc scores were predictors of survival p=0.005 and p<0.001, respectively (Figure). For CHADS2, mean survival times were 5.9±3.7 years for scores 0–1, 5.0±3.0 years for scores 2–4 and 4.3±2.6 years for scores ≥5. For CHA2DS2-VASc mean survival times were 7.3±4.0 years for scores 0–1, 5.6±2.9 years for scores 2–4 and 4.8±2.1 years for scores ≥5. The incidence of death was 20.1% for CHADS2 0–1, 24.8% for CHADS2 2–4, and 35.3% for CHADS2 ≥5, p=0.186. The incidence of AF was 50.2% for CHADS2 0–1, 47.9% for CHADS2 2–4, and 76.5% for CHADS2 ≥5, p=0.073. The incidence of AF related death was 13.0% for CHADS2 0–1, 16.8% for CHADS2 2–4, and 35.3% for CHADS2 ≥5, p=0.031. The incidence of death was 16.8% for CHA2DS2-VASc 0–1, 26.2% for CHA2DS2-VASc 2–4, and 45.0% for CHA2DS2-VASc ≥5, p=0.001. The incidence of AF was 49.6% for CHA2DS2-VASc 0–1, 52.5% for CHA2DS2-VASc 2–4, and 72.5% for CHA2DS2-VASc ≥5, p=0.035. The incidence of AF related death was 12.2% for CHA2DS2-VASc 0–1, 16.0% for CHA2DS2-VASc 2–4, and 42.5% for CHA2DS2-VASc ≥5, p<0.001. Conclusion Both CHADS2 and CHA2DS2-VASc scores predict long-term outcomes after surgical ablation for AF. However, CHA2DS2-VASc was superior in predicting death, AF, and AF-related death. Survival curves Funding Acknowledgement Type of funding source: None


2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 641-641
Author(s):  
Andrew Kingston ◽  
Holly Bennett ◽  
Louise Robinson ◽  
Lynne Corner ◽  
Carol Brayne ◽  
...  

Abstract The combined contribution of multi-morbidity and socio-economic position (SEP) to trends in disability free life expectancy (DFLE) is unknown. We use longitudinal data from the Cognitive Function and Ageing Studies (CFAS I: 1991; CFAS II: 2011), with two year follow up. Disability was defined as difficulty in activities of daily living, and SEP as area-level deprivation. Multi-morbidity was constructed from nine self-reported health conditions and categorised as 0-1, 2-3, 4+ diseases. In 1991 and 2011, shorter total and disability-free years were associated with greater multi-morbidity. Between 1991 and 2011, gains in life expectancy and DFLE were observed at all levels of multi-morbidity, the greatest gain in DFLE being 4 years for men with 0-1 diseases. As multi-morbidity is more prevalent in more disadvantaged groups, further analyses will investigate whether SEP differences remain at all levels of multi-morbidity.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
C Perings ◽  
C Wolff ◽  
A Wilk ◽  
A Witthohn ◽  
R Voss ◽  
...  

Abstract Introduction In 30% of patients with syncope, the underlying cause remains unexplained after clinical investigations. Unexplained syncope tends to recur, significantly impacting patients' quality of life of patients and mortality. Thus, there is a need for timely and more accurate diagnosis to initiate treatment. Dedicated care pathways are recommended by ESC guidelines. Purpose Patients with recurrent syncope were followed over time and patient outcomes with ILR were compared to patients with the same syncope burden, age, gender and mortality risk score who did not receive an ILR. Method A representative database of 4.9 million patients insured by German company statuary health insurances (BKK) was analysed over a time period of 10 years, 2007–17. Patients with recurrent syncope (two times ICD-10 GM diagnosis codes R55), age between 45–84 and no diagnosis code for the syncope were included in the analysis and followed for at least 2 years. Patients with ILR were matched to patients without ILR based on age, gender and Charlson Comorbidity index (CCI) using mahalanobis distances. The index event was the device implant in the ILR group and the second syncope event in the control group. Life expectancy, syncope hospitalisations, fall related injuries, health care costs, diagnoses and treatment rates were compared between the groups. Results A total of 412 patients with ILR for recurrent unexplained syncope were matched to the control group. Overall mean age was 68, mean was CCI 2.7, 42% were females. The risk of death was 2.35 times higher in the control group during follow up as shown in Figure 1 (p-value logrank test <0.0001). Cardiovascular related diagnosis and treatment rates were higher in the ILR group with 69% of patients having a cardiology diagnosis compared to 41% in the control group. Over a quarter (27%) of ILR patients received an implantable cardiac device compared to 5% in the control group. Ablation rates were 7% in the ILR group compared to 0% in the control group. Median health care costs were € 3,847 higher in the ILR group including the costs of the ILR implant, follow up and higher rates of cardiac treatments. These extra costs appear moderate given the substantially higher mortality risk in the control group. Conclusion This study of patients with recurrent unexplained syncope shows a remarkable difference in life expectancy in patients with ILR compared to a matched control group. Two large claim data analysis have recently shown higher rates of cardiovascular death as well as all-cause mortality in patients with unexplained syncope. A more vigilant cardiac workup might be needed to identify a possible underlying cardiac condition. Higher rates of cardiac device therapy in the ILR group were likely to play an important role for their better life expectancy. Cardiac therapies such as pacemakers, defibrillators and ablation have also been shown to significantly improve patients' quality of life. Life Expectancy Comparison Funding Acknowledgement Type of funding source: Private company. Main funding source(s): The data analysis was funded by Medtronic


Heart ◽  
2021 ◽  
Vol 107 (5) ◽  
pp. 389-395
Author(s):  
Jianhua Wu ◽  
Alistair S Hall ◽  
Chris P Gale

AimsACE inhibition reduces mortality and morbidity in patients with heart failure after acute myocardial infarction (AMI). However, there are limited randomised data about the long-term survival benefits of ACE inhibition in this population.MethodsIn 1993, the Acute Infarction Ramipril Efficacy (AIRE) study randomly allocated patients with AMI and clinical heart failure to ramipril or placebo. The duration of masked trial therapy in the UK cohort (603 patients, mean age=64.7 years, 455 male patients) was 12.4 and 13.4 months for ramipril (n=302) and placebo (n=301), respectively. We estimated life expectancy and extensions of life (difference in median survival times) according to duration of follow-up (range 0–29.6 years).ResultsBy 9 April 2019, death from all causes occurred in 266 (88.4%) patients in placebo arm and 275 (91.1%) patients in ramipril arm. The extension of life between ramipril and placebo groups was 14.5 months (95% CI 13.2 to 15.8). Ramipril increased life expectancy more for patients with than without diabetes (life expectancy difference 32.1 vs 5.0 months), previous AMI (20.1 vs 4.9 months), previous heart failure (19.5 vs 4.9 months), hypertension (16.6 vs 8.3 months), angina (16.2 vs 5.0 months) and age >65 years (11.3 vs 5.7 months). Given potential treatment switching, the true absolute treatment effect could be underestimated by 28%.ConclusionFor patients with clinically defined heart failure following AMI, ramipril results in a sustained survival benefit, and is associated with an extension of life of up to 14.5 months for, on average, 13 months treatment duration.


2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
V Gastens ◽  
C Del Giovane ◽  
D Anker ◽  
L Syrogiannouli ◽  
N Schwab ◽  
...  

Abstract Background Providing high value care and avoiding care overuse is a challenge among older multimorbid adults. There is evidence on benefits and harms of cancer screening and cardiovascular diseases (CVD) preventive treatment up to the age of 75. However, this evidence is not directly applicable to older multimorbid patients. Because each cancer and CVD preventive care has a specific lagtime to benefit, many guidelines recommend tailoring preventive care according to the estimated life expectancy (LE). However, there is no tool to estimate LE among multimorbid patients. Our objectives are therefore to develop new mortality risk prognostic indices and to derive a new LE estimator, what will help clinicians tailoring preventive care in older multimorbid adults. Methods and Results We conduct a prospective cohort study by extending the follow-up of 822 patients in Bern, Switzerland, included in the OPtimising thERapy to prevent Avoidable hospital admissions in Mulitmorbid older people (OPERAM) study over 3 years. Detailed information about cancer screening and CVD preventive treatment will be collected. We will identify variables independently associated with mortality and weight the variables to create 1 year and 3 year mortality prognostic indices. We will transform the 3 year prognostic index into a LE estimator. Preliminary results will be presented at the congress. Conclusions We will develop the first life expectancy estimator specifically for older multimorbid adults. This tool will help clinicians to tailor cardiovascular and cancer preventive care in older multimorbid adults. Key messages Because of the lagtime to benefit, personalizing preventive care by estimated life expectancy is recommended. We will provide the first life expectancy estimator for older multimorbid adults.


2000 ◽  
Vol 18 (5) ◽  
pp. 987-987 ◽  
Author(s):  
Howard S. Hochster ◽  
Martin M. Oken ◽  
Jane N. Winter ◽  
Leo I. Gordon ◽  
Bruce G. Raphael ◽  
...  

PURPOSE: To determine the toxicity and recommended phase II doses of the combination of fludarabine plus cyclophosphamide in chemotherapy-naive patients with low-grade lymphoma. PATIENTS AND METHODS: Previously untreated patients with low-grade lymphoma were entered onto dosing cohorts of four patients each. The cyclophosphamide dose, given on day 1, was increased from 600 to 1,000 mg/m2. Fludarabine 20 mg/m2 was administered on days 1 through 5. The first eight patients were treated every 21 days; later patients were treated every 28 days. Prophylactic antibiotics were required. RESULTS: Prolonged cytopenia and pulmonary toxicity each occurred in three of eight patients treated every 3 weeks. The 19 patients treated every 28 days, who were given granulocyte colony-stimulating factor as indicated, did not have undue nonhematologic toxicity. Dose-limiting toxicity was hematologic. At the recommended phase II/III dose (cyclophosphamide 1,000 mg/m2), grade 4 neutropenia was observed in 17% of all cycles and 31% of first cycles. Grade 3 or 4 thrombocytopenia was seen in only 1% of all cycles. The median number of cycles per patient was six (range, two to 11) for all patients enrolled. The response rate was 100% of 27 patients entered; 89% achieved a complete and 11% a partial response. Nineteen of 22 patients with bone marrow involvement had clearing of the marrow. Median duration of follow-up was more than 5 years; median overall and disease-free survival times have not been reached. Kaplan-Meier estimated 5-year overall survival and disease-free survival rates were 66% and 53%, respectively. CONCLUSION: The recommended dosing for this combination in patients with previously untreated low-grade lymphoma is cyclophosphamide 1,000 mg/m2 day 1 and fludarabine 20 mg/m2 days 1 through 5. The regimen has a high level of activity, with prolonged complete remissions providing 5-year overall and disease-free survival rates as high as those reported for other therapeutic approaches in untreated patients.


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