SURVIVAL ANALYSIS FOR THE RISK OF DEVELOPING HEART ATTACK
Keywords:Cox Regression, Hazard Function, Heart Attack, Kaplan-Meier Estimates, SPSS, Survival Analysis, Survival Functions
Heart disease is the leading cause of death among Filipinos, accounting for 1 out of every 5 deaths in the past year. Each year, 170,000 Filipinos die from cardiovascular diseases, up from 85,000 more than 20 y ago. This paper aims to estimate the risk of developing Heart Attack using Survival Analysis. The data were obtained from the records of Quirino Memorial Medical Center with a total of 447 observations. The data includes the time t (patient's age), gender of the patient, covariates such as lifestyle (smoking and drinking alcohol); health conditions (Hypertension, Diabetes, High-density Lipoprotein (HDL) and Low-density Lipoprotein (LDL) level); and family history of Cardiovascular Disease, and the event of interest which is the occurrence of heart attack. The researchers applied two main statistical treatments in examining the data: (1) Cox Regression in formulating a model to estimate the risk of heart attack based on the given covariates; (2) Kaplan-Meier Estimates in calculating the probability of each patient to survive in accordance to their gender depending on the covariates the patients have. Results showed that females have more risks of developing heart attack than males for patients with hypertension, with diabetes, with a family history of CVD, and those who are smoking. However, for patients who are alcoholic, men are more prone to the risk of heart attack than women. The results were obtained with the help of SPSS.
ABS-CBN News. Heart disease is PHâ€™s top killer: NSO. Available from http://www.abs-cbnnews.com/lifestyle/10/20/11/heart-disease-phs-top-killer-nsowww.abscbnnews.com/lifestyle/10/ 20/11/heart-disease-phs-top-killer-nso. [Last accessed on 10 Oct 2011].
GMA News Online. Philippine Heart Association releases updated guidelines for Coronary Artery Disease. Available from: http://www.gmanetwork.com/news/story/390361/lifestyle/healthandwellnes/philippine-heart-association-releases-updated-guidelines-for-coronary-artery-disease. [Last accessed on 29 Nov 2014].
Living Heart Foundation. Heart Attack. Available from: http://www.livingheartfoundation.org/heartattack.pdf. [Last accessed on 29 Nov 2014].
Mayo Clinic. Causes of Heart Attack. Available from: http://www.mayoclinic.org/diseases-conditions/heart-attack/ basics/causes/con-20019520. [Last accessed on 29 Nov 2014].
National Heart, Lung and Blood Institute. What Causes a Heart Attack? Available from: http://www.nhlbi.nih.gov/health/health-topics/topics/heartattack/causes. [Last accessed on 28 Nov 2014].
Mayo Clinic. Risk Factors of Heart Attack. Available from: http://www.mayoclinic.org/diseases-conditions/heart-attack/ basics/risk-factors/con-20019520. [Last accessed on 25 Nov 2014].
Better Health Channel. Heart Attackâ€“Risk Factors. Available from:http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Heart_disease_your_risk-factors_explained?open. [Last accessed on 29 Nov 2014].
Hui Bian. (nd). Survival Analysis using SPSS. Available from: http://core.ecu.edu/ofe/StatisticsResearch/Survival%20Analysis%20Using%20SPSS.pdf. [Last accessed on 29 Nov 2014].
Manish Kumar Goel, Pardeep Khanna, and Jugal Kishore. Understanding Survival Analysis: Kaplan-Meier Estimate. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/ PMC3059453/. [Last accessed on 15 Jan 2011].
Vassar Stats. Kaplan-Meier Survival Probability Estimates. Available from: http://vassarstats.net/survival.html. [Last accessed on 15 Jan 2011].
MBA Skool. Log-Rank Test. Available from: http://www. mbaskool.com/business-concepts/statistics/8764-log-rank-test-.html. [Last accessed on 15 Jan 2014].
Martin J Bland, Douglas G Altman. The log-rank test. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/ PMC403858/ . [Last accessed on 01 May 2004].
Lu Tian, Richard Olshen. (nd). Survival Analysis: Log rank test. Available from: http://web.stanford.edu/~lutian/coursepdf/ survweek3.pdf. [Last accessed on 01 May 2004].
Stats Direct. Cox (Proportional Hazards) regression. Available from: http://www.statsdirect.com/help/default.htm# survival _analysis/cox_regression.htm. [Last accessed on 09 May 2014].
Math Works. Cox proportional hazards regression. Available from:http://www.mathworks.com/help/stats/cox-proportional- hazard-regression.html. [Last accessed on 08 May 2014].
Harrell Jr, Frank E. Regression modeling strategies. Available from: www.springer.com/gb/book/9781441929181. [Last accessed on 01 May 2015].
MJ Bradburn, TG Clark, SB Love, DG Altman. Survival analysis part II: multivariate data analysisâ€“an introduction to concepts and methods. Available from: http://www.ncbi. nlm.nih. gov/pmc/articles/PMC2394368/. [Last accessed on 29 Jul 2003].
Gibbons, Gary H. How does heart attack affect women? Available from: http://www.nhlbi.nih.gov/health/health-topics/topics/hdw. [Last accessed on 11 May 2015].