2 2. Methods We conducted a prospective cohort study with one-year followup. The Queen’s University Health Sciences and Aﬃl- iated Teaching Hospitals Research Ethics Board (Kingston, Ontario) reviewed and approved the study protocol. 2.1. Participant Sample. Potential participants were recruited from one tertiary teaching centre in Kingston, Ontario, and 3 community hospital corporations in the surrounding region. Recruitment was carried out between March 2003 and September 2007; followup continued until January 2009. Participants were included if they were aged 65 years and older and seen in the emergency department (ED) with a diagnosis of HF or HF-related complaint. The HF diagnosis was conﬁrmed through chart review in accordance with the Framingham Criteria for Congestive Heart Failure [12]. Participants were excluded if they lived in such institutions as nursing homes, or long-term care facilities. The study cohort consisted of 435 study participants who provided informed consent and completed baseline questionnaires. Given the observed gender distribution and loss to follow-up rate, our eﬀective sample size achieves over 85% at a two-sided alpha = .05 to compare functional decline rates between genders if the true absolute diﬀerence is at least 10%. Furthermore, our eﬀective sample size provides at least 80% power at alpha = .05 (two-sided) to test the association between social support and functional decline if a one standard deviation change in the social support subscale results in at least 10% diﬀerence in the proportion of patients who decline (regardless of outcome). 2.2. Data Collection Procedure. All consecutive ED dis- charge records were reviewed for potential participants who met inclusion criteria. Once informed consent was obtained, baseline information was collected either in hos- pital or obtained after discharge. Participants completed self-report questionnaires at baseline and 12 months in home and returned the package in a self-addressed enve- lope. If questionnaires were not returned at the desig- nated time interval, the research coordinator contacted the participant and encouraged the participants to complete the questionnaire. In some cases, the participant provided questionnaire responses over the phone and the research coordinator completed the questionnaire. Data were entered into a secure computerized data base system maintained in the Nursing Research Unit at Kingston General Hospital, Kingston, Ontario. Data entry accuracy was veriﬁed by a second research associate. During the one-year follow-up period, survival status was determined through hospital records or through phone contact with family. 3. Measures Cardiology Research and Practice City Cardiomyopathy Questionnaire (KCCQ), or (b) overall health-related quality of life as measured by the physical component summary scale (PCS) of the SF-12 Health Survey. The Kansas City Cardiomyopathy Questionnaire (KCCQ) is a disease-speciﬁc, 23-item questionnaire that quantiﬁes the following domains: physical limitation, symptoms (fre- quency, severity, and recent change), social limitation, self- eﬃcacy and knowledge, and quality of life. Scale scores are transformed to a 0 to 100 range by subtracting the lowest possible scale score, dividing by the range of the scale and multiplying by 100. This tool is a valid, reliable self-reported health status measure for patients with HF. Cronbach’s alphas for each domain indicate high internal consistency, except for self-eﬃcacy that has moderate internal consistency (.62) [13]. As we were most interested in physical function, we focused solely on the physical limitation (PL) score of the KCCQ. Based on the literature, we deﬁned clinically important changes in PL as a 5-point change in score in either direction between baseline and 12 months [14, 15]. Participants were then classiﬁed accordingly: (1) improve- ment or maintenance of physical function, (2) decline in physical function, (3) death within the 12-month followup, (4) withdrawal from the study due to worsening illness, and (5) lost to followup/withdrawal for unknown reasons [14– 16]. The physical component summary scale (PCS) of the SF- 12 Health Survey was selected as a brief, patient-reported outcome for overall physical health status. The SF-12 is reliable and has been a validated tool used to measure self- reported generic functioning and well-being in numerous medical and surgical populations [17, 18]. Mean reliability coeﬃcients are reported between .64 and .87 for the physical dimension. Using PCS scores at baseline and 12 months, a similar 5-level categorical outcome variable was created based on clinically signiﬁcant changes. Based on the litera- ture, we used a 2-point change in PCS to reﬂect a clinically signiﬁcant change in function [19, 20]. Similar to the KCCQ- PL categorical classiﬁcation, participants were classiﬁed into the 5 levels using the PCS change score. 3.2. Exposure Variable of Interest: Social Support. Social sup- port was measured using the Medical Outcome Survey-Social Support Survey (MOS-SSS). The MOS-SSS is a 20-item self- report tool that measures four aspects of functional support including emotional/informational, tangible, aﬀectionate, and positive social interaction [21]. Scores range from 0 to 100, with higher scores indicating higher levels of perceived support. Bennett and colleagues [2] used the MOS-SSS to measure social support to determine associations between support and health-related quality of life in 227 hospitalized HF patients. Mean overall scores (±SD) at baseline were 56 (±18.2) and 53 (±20.1) at 12 months, with a score of 76 indicating positive perceptions of support [2]. 3.1. Primary Outcome: Physical Function. The primary out- come of interest was clinically important changes in physical function as related to (a) heart disease, measured by the physical limitation (PL) subscale score from the Kansas 3.3. Personal Characteristics. Age, gender, income, educa- tional level, and health habits were recorded at baseline by self-report and were used to describe the sample. Home sup- ports such as living arrangements, housing arrangements,