Clinicians who care for persons with complex chronic medical conditions face both competing demands and a lack of evidence regarding best processes of care for this heterogeneous population. Those clinicians facing decisions about prevention of coronary heart disease (CHD) following a new diagnosis of cancer must take into account cancer prognosis, cardiovascular risk status, overall burden of morbidity, and the patient's goals, preferences and values. To help inform such decisions, we propose to use analytic epidemiology methods to study an historical cohort of all (over 30,000) Kaiser Permanente Colorado (KPCO) adult members who received an initial diagnosis of cancer during the period 1999 to 2007. In this cohort, we will a) assess the attainment of goals for specific components of primary, secondary, and 'tertiary'prevention of CHD as a function of cancer prognosis, overall morbidity and the interaction between them, and b) assess the comparative effectiveness of these CHD prevention interventions (in relevant sub-cohorts) on receipt of, and time to, a composite of CHD events and all-cause mortality. We hypothesize that: a) Overall morbidity, cancer prognosis, and the interaction between them will affect attainment of goals of preventive interventions for CHD;and b) specific strata of morbidity and cancer prognosis will modify the effectiveness of these interventions on the CHD outcomes. In evaluating these prevention strategies on CHD outcomes, we will study the processes of care for the comorbidities of hypertension, diabetes, hyperlipidemia, and pre-existing CHD. We will use linear regression models and Cox proportional hazard models to assess the impact of the cancer prognosis and other morbidity scores (and their interactions) on the CHD prevention outcomes. A Cox proportional hazards model will be used to assess the effectiveness of the prevention measures on time to the CHD composite outcome across strata defined by prognosis/morbidity. Finally, we will describe which prevention measures most influence which components of the CHD outcomes. Information from this investigation will inform recommendations for the use of these specific preventive interventions in patients with a range of morbidities in order to make these recommendations congruent with an evidence base that acknowledges complex patients'priorities, time, and resources. PUBLIC HEALTH RELEVANCE: Relevance if we find differences in the comparative effectiveness of certain components of coronary heart disease prevention interventions across different levels of morbidity, policy implications could range from informing guideline development for the care of complex patients, to changes in reimbursement strategies for clinician time involved in shared decision-making. More importantly, findings will provide complex patients and their clinicians with additional information to inform personalized decisions across a spectrum of care.