Biostatistics and epidemiology: measuring the risk attributable to an environmental or genetic factor

Bénichou, Jacques

doi:10.1016/j.crvi.2007.02.015

Cited by 39 publications

(34 citation statements)

References 115 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Differences in PAR can be caused by a difference in effect size or a difference in prevalence. 33 The PAR in our study was mostly driven by the higher prevalence of diabetes mellitus, smoking, and atrial fibrillation in people with stroke, probably because these factors are also important risk factors for the stroke itself. 40 Interestingly, we found effect modification of stroke for the effect of atrial fibrillation and underweight with stronger effect sizes for death in people with stroke than in people without stroke.…”

Section: Discussionmentioning

confidence: 98%

See 1 more Smart Citation

Role of Prestroke Vascular Pathology in Long-Term Prognosis After Stroke

Portegies

Bos

Hofman

et al. 2016

Stroke

View full text Add to dashboard Cite

Background and Purpose-Mortality after stroke remains high for years, mostly because of cardiovascular causes. Given that cardiovascular pathology plays an important role in causing the initial stroke, such prestroke pathology might also influence the prognosis after stroke. Within the population-based Rotterdam Study, we examined the proportion of deaths after stroke that are attributable to pre-existent cardiovascular risk factors before stroke (the population attributable risk). Methods-We examined 1237 patients with first-ever stroke and 4928 stroke-free participants (between 1990 and 2012), matched on age, sex, examination round, and stroke date (index date). Cardiovascular risk factors measured on ≈4 years before index date were used as determinants. Participants were continuously followed up for mortality (≈6 years) after the index date. We calculated separate and combined population attributable risk of hypertension, total cholesterol, high-density lipoprotein-cholesterol, body mass index, diabetes mellitus, smoking, transient ischemic attack, and atrial fibrillation. Results-Nine hundred and nineteen patients with stroke and 2654 stroke-free participants died. The combined population attributable risk in patients with stroke was 27% (95% confidence interval, 14%-45%) and in stroke-free participants was 19% (95% confidence interval, 12%-29%). Population attributable risks of diabetes mellitus, smoking, and atrial fibrillation were higher in patients with stroke than in the reference group because of a higher prevalence of risk factors. In addition, people with atrial fibrillation and stroke had a higher hazard ratio for death than those with only atrial fibrillation. Conclusions-One quarter of deaths after stroke could theoretically be prevented with rigorous cardiovascular prevention and treatment, but this should preferably start before stroke occurrence. In addition, research into factors explaining the remaining deaths needs to be encouraged.

show abstract

Section: Discussionmentioning

confidence: 98%

“…PARs cannot be calculated for an HR <1 because this will result in a PAR that cannot be interpreted. 33 We checked the proportional hazards assumption by inspecting log minus log plots. Follow-up started at the index date.…”

Section: Discussionmentioning

confidence: 99%

Role of Prestroke Vascular Pathology in Long-Term Prognosis After Stroke

Portegies

Bos

Hofman

et al. 2016

Stroke

View full text Add to dashboard Cite

show abstract

“…The combined PAR included the PARs of modifiable risk factors which were associated with an increased risk of recurrent stroke or dementia. 14 We provide logit transformed 95% CI for the PARs as they are more easily interpretable and more stringent with regard to our combined PAR estimate. 15 Because of small numbers, we did not explore the PAR for subtypes of stroke and dementia.…”

Section: Discussionmentioning

confidence: 99%

Prestroke Vascular Pathology and the Risk of Recurrent Stroke and Poststroke Dementia

Portegies¹,

Wolters²,

Hofman³

et al. 2016

Stroke

View full text Add to dashboard Cite

Survival after stroke has improved over the past decades, thanks to thrombolytic therapy, specialized stroke units, and better secondary prevention.1,2 However, such improved survival may lead to more people having long-term hazards of stroke, such as recurrent stroke and dementia.3,4 These longterm risks after stroke are not well documented, nor are the factors that determine this risk. In this regard, risk factors that lead to the initial stroke may also predispose to clinical adverse events after stroke. Indeed, we previously showed that 27% of all deaths after stroke can be attributed to risk factors already present before stroke. 5 We now expand on that previous report by investigating recurrent stroke and poststroke dementia and how these are affected by prestroke risk factors. MethodsExtensive details on the Methods are presented in the online-only Data Supplement and are largely identical to a previous article.5 Briefly, this study was embedded within the population-based Rotterdam Study, 6 which totals 14,926 participants aged >45 years, who were repeatedly examined every 4 years. We selected 1243 participants who had an incident stroke between 1990 and 2012 and matched these to 4 participants without stroke with matching done on date of selection, age, sex, and visit to the same examination round, using an incidence density sampling. Participants were then followed up for the occurrence of stroke or dementia until January 1, 2012. In total, 1237 participants with stroke and 4928 stroke-free participants were eligible for the analyses with recurrent stroke and, respectively, 993 and 4363 for the dementia analyses ( Figure I and Table I in the online-only Data Supplement). ResultsRisk of recurrent stroke and dementia was highest in the shortterm, but even beyond the first year, the risk of recurrent stroke (incidence rate ratio, 3.16 [95% confidence interval, 2.59-3.85]) and dementia (incidence rate ratio, 1.73 [1.38-2.17]) remained increased. However, these differences were only statistically significant from years 1 to 5 (Figure).Participants with stroke had a worse cardiovascular profile than participants without stroke (Table I online-only Data Supplement). Main factors contributing to a recurrent Background and Purpose-Improved short-term survival after stroke has necessitated quantifying risk and risk factors of long-term sequelae after stroke (ie, recurrent stroke and dementia). This risk may be influenced by exposure to cardiovascular risk factors before the initial stroke. Within the population-based Rotterdam Study, we determined the long-term risk of recurrent stroke and dementia, and the proportion of recurrent strokes and poststroke dementia cases that are attributable to prestroke cardiovascular risk factors (ie, the population attributable risk). Methods-We followed up 1237 patients with first-ever stroke and 4928 stroke-free participants, matched on age, sex, examination round, and stroke date (index date), for the occurrence of stroke or dementia. We calculated incidence rates in...

show abstract

“…2,3,13,14 To obtain more precise estimates in future work will likely require the use of a common reference group with all exposures and their interactions simultaneously included in the analysis, requiring more advanced epidemiologic methods. 15,16,17,18 In conclusion, future research should seek to better understand the epidemiologic analysis methods that are most appropriate in the new and emerging field of naturalistic driving research.…”

Section: Discussionmentioning

confidence: 99%

Naturalistic Studies of Driver Distraction: Effects of Analysis Methods on Odds Ratios and Population Attributable Risk

Young

2013

Proceedings of the 7th International Driving Symposium on Human Factors in Driver Assessment, Training, and Vehicle Design : Dr

View full text Add to dashboard Cite

Summary:When analyzing naturalistic driver performance data, different analysis methods can have large impacts on safety estimates for the condition being assessed. To illustrate, this paper reanalyzed the data for a secondary task (conversation on a hand-held cell phone) from the recently-released Virginia Tech Transportation Institute (VTTI) 100-Car databases, using a standard method for epidemiological analysis. It found substantially lower estimates for the odds ratio (OR), population exposure percent (P e %), and population attributable risk percent (PAR%) than with the VTTI analysis method. The crash/near-crash OR was reported by VTTI as 1.29, but was found to be 0.78 with the standard method, a reversal in direction from a potentially crash-increasing to a potentially crash-reducing effect. The P e % for crashes/near-crashes was 12.5% using the VTTI method, but declined to 6.7% with the standard method. The PAR% was reported as 3.6% but a population preventive fraction of 1.5% (a protective effect) was estimated by the standard method. The OR difference was traced to an "assumption bias" in the VTTI method that had unequal effects for the unexposed vs. exposed cases. The P e % and PAR% differences were traced to an error in the VTTI calculation of P e %. This bias and error were systemic in the VTTI analysis methods, overestimating OR, P e %, and PAR% for all tasks examined. Future research should seek to better understand the epidemiologic analysis methods that are most appropriate in the new and emerging field of naturalistic driving research.

show abstract

Biostatistics and epidemiology: measuring the risk attributable to an environmental or genetic factor

Cited by 39 publications

References 115 publications

Role of Prestroke Vascular Pathology in Long-Term Prognosis After Stroke

Role of Prestroke Vascular Pathology in Long-Term Prognosis After Stroke

Prestroke Vascular Pathology and the Risk of Recurrent Stroke and Poststroke Dementia

Naturalistic Studies of Driver Distraction: Effects of Analysis Methods on Odds Ratios and Population Attributable Risk

Contact Info

Product

Resources

About