Women with coronary heart disease (CHD) are consistently less likely than men with CHD to be at low-density lipoprotein (LDL) cholesterol goals, and the reasons for the gender gap are not established. We studied 2,190 patients with CHD or equivalent (34% women, 42% racial/ethnic minority) who participated in the Family Cardiac Caregiver Investigation to Evaluate Outcomes (FIT-O) Study and had baseline lipid data to determine whether having a paid or informal caregiver was independently associated with adherence to LDL cholesterol goals (<100, <70 mg/dl) and statin use and to determine if the association varied by gender. Caregiver status was assessed by standardized questionnaire and lipid levels/statin use were obtained from a hospital-based informatics system. Associations between caregiving and LDL cholesterol and statin use were assessed in univariate and multivariable models and the interaction was evaluated in gender stratified models. Men with CHD were more likely to be at LDL cholesterol goals <100 and <70 mg/dl and on statins than women with CHD (79% vs 69%, p <0.001; 48% vs 36%, p <0.001; 73% vs 67%, p = 0.004, respectively). No significant association was observed between LDL cholesterol <100 mg/dl and informal caregiving or between paid caregiving and lipid goals or statin use. Having an informal caregiver was associated with having an LDL cholesterol <70 mg/dl (p = 0.016), which remained significant after adjustment in multivariable models (odds ratio 1.25, 95% confidence interval 1.00 to 1.56). Multivariable association between informal caregiving and LDL cholesterol was significant in men (odds ratio 1.37, 95% confidence interval 1.04 to 1.80) but not women. In conclusion, there was a significant association between informal caregiving and LDL cholesterol control that was limited to men with informal caregivers.
Low-density lipoprotein (LDL) cholesterol reduction and statin therapy have proven benefits in the secondary prevention of coronary heart disease (CHD) for men and women. Despite this, data consistently have shown that women with CHD are significantly less likely to reach LDL cholesterol targets or to be on statin therapy compared to their male counterparts. Reasons for the gender gap remain elusive, and an unexplored mechanism may be differential access to type or quality of caregivers. Informal caregivers such as family members or friends are often involved in tasks such as assistance with medications and other preventive care that might be associated with better CHD risk factor control. Few data have examined whether caregiving is associated with better lipid management or the gap in the understanding of gender disparities. The purpose of this study was to determine whether having a caregiver (paid or informal) was associated with adherence to National Cholesterol Education Program Adult Treatment Panel III (ATP III) and American Heart Association (AHA) secondary prevention guidelines for LDL cholesterol goals (<100 and <70 mg/dl) and statin use in hospitalized patients with CHD and whether the association varied by patient gender.
Methods
This was a cross-sectional analysis of 2,190 patients who participated in the National Heart, Lung, and Blood Institute–sponsored Family Cardiac Caregiver Investigation to Evaluate Outcomes (FIT-O) Study who had previous CHD or equivalent and had documented LDL cholesterol within 12 months of hospital admission (n = 2,190, 34% women, 42% racial/ethnic minority). The design and methods of FIT-O have been previously reported. Briefly, FIT-O was a prospective cohort study that evaluated patterns of caregiving and the association with clinical outcomes in patients with CHD consecutively admitted to an academic medical center (93% enrollment rate, n = 4,500). Patients who were unable to read or understand English or Spanish, lived in a full-time nursing facility, had a mental status that made them unable to participate, or refused to participate were excluded from the study. Participants with a documented contraindication to statin use were excluded from this analysis. The institutional review board of Columbia University Medical Center approved the study.
Trained bilingual research staff systematically distributed surveys (available in English and Spanish) to participants to determine whether they had a caregiver within the previous year or planned to have a caregiver after hospital discharge. The definition of caregiving was adapted from the report of the National Alliance of Caregiving and the American Association of Retired Persons. A caregiver was defined as someone who assists the patient with medical and/or preventative care and was categorized into 2 groups: (1) paid professional (e.g., nurse or home aide) or (2) informal/nonpaid (e.g., family member or friend). If a patient had a paid and an informal caregiver, she or he was categorized as having a paid caregiver (n = 80). Patients who reported having a caregiver in the year before hospitalization were classified as a having a caregiver in this analysis.
Admission diagnosis, baseline characteristics, medical history, and prescription medications were documented by standardized electronic chart review by trained professional research staff. A secure and comprehensive electronic clinical information system at Columbia University Medical Center/New York Presbyterian Hospital was used to access and review patient medical records. Admission diagnosis was classified using the International Classification of Disease, Ninth Revision billing code for admission or primary diagnosis. The definition and classification of CHD equivalent was adapted from the National Heart, Lung, and Blood Institute ATP III report. Patients were classified as having CHD or equivalent if they had an International Classification of Disease, Ninth Revision billing code consistent with ischemic heart disease, myocardial infarction, previous coronary artery bypass graft surgery, noncardiac atherosclerotic disease, peripheral artery disease, abdominal aortic aneurysm, or diabetes mellitus. Co-morbidities were determined based on electronic chart review and a summary Ghali co-morbidity index was calculated (range 0 to 11).
LDL cholesterol values obtained closest to within 24 hours of admission were defined as admission LDL cholesterol. If an admission LDL cholesterol was not available (n = 362), LDL cholesterol values from within 1 year of hospital admission date were used. LDL cholesterol was calculated according to the Friedewald equation: LDL cholesterol equals total cholesterol minus high-density lipoprotein cholesterol minus (triglycerides divided by 5). Serum total cholesterol, high-density lipoprotein cholesterol, and triglycerides were measured using the Beckman Coulter analyzer (Brea, California) in the core laboratory of Columbia University Medical Center/New York Presbyterian Hospital. The main results were similar when patients with triglycerides ≥400 mg/dl (n = 13) were excluded, so they were retained in the analyses. LDL cholesterol goals and indication for statin use were defined according to ATP III and AHA secondary prevention guidelines and categorized as minimum goal LDL cholesterol <100 mg/dl and optional goal LDL cholesterol <70 mg/dl and statin use unless contraindicated.
Standardized questionnaires regarding caregiver status and activities were processed using intelligent character recognition software ExDataPro32 8.0.7 (Creative ICR, Beaverton, Oregon) and Image Formula Dr-2,580C (Canon USA, New York, New York). Data were double checked for errors and stored in a Microsoft Access database (Microsoft, Redmond, Washington). Chi-square tests were conducted to determine the association between having a caregiver (paid or informal) and baseline characteristics of hospitalized patients with CHD using a Bonferroni correction for multiple comparisons (p <0.017). Independent associations between caregiving and LDL cholesterol goals and statin use were evaluated using logistic regression adjusted for demographics (age, gender, health insurance status, and marital status), Ghali co-morbidity index, diabetes, current smoking, being on ≥9 medications, and statin use. Gender-stratified analyses and interaction terms were evaluated to assess for effect modification by gender.
Results
Baseline characteristics of participants stratified by caregiver status are listed in Table 1 . Mean age of hospitalized patients with CHD was 67 ± 12 years. Approximately 34% of participants were women and 42% were racial/ethnic minorities. Prevalence of attainment of goal LDL cholesterol <100 mg/dl was 76% overall and differed significantly by gender with men being more likely than women to attain goal LDL cholesterol <100 mg/dl (p <0.0001), as shown in Figure 1 . Similarly, attainment of the more intensive goal LDL cholesterol <70 mg/dl, which was 44% overall, was more prevalent in men than women (p <0.0001). Overall, 72% of patients in this study were on a statin, which also varied significantly by gender with more men than women being on a statin (p = 0.004).
| Variable | Have Paid Caregiver a | Have Informal Caregiver b | Have No Caregiver c |
|---|---|---|---|
| (n = 283) | (n = 596) | (n = 1,311) | |
| Age ≥ 65 | 220 (78%) bc | 349 (59%) a | 691 (53%) a |
| Men | 132 (47%) bc | 426 (71%) a | 888 (68%) a |
| Minority race/ethnicity ⁎ | 130 (51%) c | 242 (44%) | 497 (39%) a |
| Not married † | 135 (58%) bc | 191 (38%) ac | 500 (45%) ab |
| No health insurance | 66 (23%) bc | 87 (15%) a | 154 (12%) a |
| Ghali co-morbidity index ≥1 | 188 (66%) bc | 277 (47%) ac | 445 (34%) ab |
| Diabetes mellitus | 169 (60%) bc | 302 (51%) ac | 549 (42%) ab |
| Chronic renal disease | 99 (35%) bc | 127 (21%) ac | 199 (15%) ab |
| Previous stroke | 50 (18%) c | 72 (12%) c | 110 (8%) ab |
| Previous coronary artery disease | 109 (39%) bc | 337 (57%) ac | 881 (68%) ab |
| Previous myocardial infarction | 108 (38%) | 239 (40%) c | 444 (34%) b |
| Previous coronary artery bypass surgery | 86 (30%) c | 155 (26%) c | 249 (19%) ab |
| Previous peripheral vascular disease | 78 (28%) bc | 104 (17%) a | 177 (14%) a |
| Previous heart failure | 106 (37%) bc | 140 (23%) ac | 189 (14%) ab |
| Chronic obstructive pulmonary disease | 33 (12%) bc | 40 (7%) ac | 52 (4%) ab |
| Hypertension (history) | 237 (84%) | 502 (84%) | 1,059 (81%) |
| Dyslipidemia (history) | 204 (72%) | 423 (71%) | 978 (75%) |
| ≥9 medications | 176 (62%) bc | 256 (43%) ac | 446 (34%) ab |
| Current smoker | 12 (4%) bc | 52 (9%) a | 154 (12%) a |
| On statin at admission | 212 (75%) | 418 (70%) | 931 (71%) |
⁎ Missing race/ethnicity information (n = 122).
Overall prevalence of caregiving in this population was 40% (13% paid, 27% informal), similar to the larger FIT-O cohort. In men, 13% (n = 132) had a paid caregiver and 32% (n = 426) had an informal caregiver. In women, 26% (n = 151) had a paid caregiver and 29% (n = 170) had an informal caregiver. As presented in Table 2 , having a paid caregiver was not associated with LDL cholesterol goals <100 or <70 mg/dl or statin use. In contrast, having an informal caregiver was significantly associated with being more likely to be at LDL cholesterol <70 mg/dl than having no caregiver (p <0.05). There was a nonsignificant trend that participants with an informal caregiver were more likely than participants without a caregiver to be at LDL cholesterol <100 mg/dl; however, there was no relation between informal caregiving and statin use.
| Variable | LDL Cholesterol (mg/dl) | On Statin | |
|---|---|---|---|
| <100 | <70 | ||
| Paid vs no caregiver | 1.08 (0.80–1.46) | 0.93 (0.72–1.21) | 1.22 (0.91–1.64) |
| Informal vs no caregiver | 1.20 (0.95–1.51) | 1.27 (1.05–1.54) ⁎ | 0.96 (0.78–1.19) |
| Age ≥65 years | 1.38 (1.13–1.68) ⁎ | 1.33 (1.12–1.58) ⁎ | 1.23 (1.02–1.48) ⁎ |
| Men | 1.72 (1.41–2.10) † | 1.58 (1.32–1.90) † | 1.33 (1.10–1.61) ⁎ |
| Minority race | 0.56 (0.46–0.69) † | 0.63 (0.53–0.75) † | 0.73 (0.60–0.88) ⁎ |
| Not married | 0.56 (0.45–0.69) † | 0.68 (0.57–0.82) † | 0.55 (0.45–0.68) † |
| No health insurance | 0.51 (0.39–0.66) † | 0.57 (0.44–0.73) † | 0.95 (0.73–1.24) |
| Ghali index ≥1 | 1.07 (0.88–1.31) | 1.04 (0.87–1.23) | 1.05 (0.87–1.27) |
| Diabetes | 1.24 (1.01–1.51) ⁎ | 1.21 (1.02–1.43) ⁎ | 1.44 (1.19–1.73) ⁎ |
| ≥9 medications | 1.80 (1.45–2.22) † | 1.62 (1.36–1.93) † | 2.42 (1.97–2.94) † |
| Current smoker | 0.59 (0.44–0.80) ⁎ | 0.56 (0.42–0.76) ⁎ | 0.64 (0.48–0.85) ⁎ |
| On statin at admission | 3.83 (3.12–4.72) † | 3.21 (2.61–3.99) † | — |
Significant correlates (p <0.05) of LDL cholesterol <70 mg/dl were having diabetes mellitus, being on ≥9 medications, older age (≥65 years old), male gender, and being on a statin at admission. Being a racial/ethnic minority, not being married, not having health insurance, and current smoking were significantly associated with being at minimum and intensive LDL cholesterol goals. After adjustment for demographics, co-morbidities, and confounders, having an informal caregiver remained significantly associated with being at LDL cholesterol <70 mg/dl.
Results of the gender-stratified analysis of the association between caregiver status and attainment of LDL cholesterol goals and statin use are presented in Table 3 . Among men, having an informal caregiver was significantly associated (p <0.05) with being at LDL cholesterol <70 mg/dl and there was a nonsignificant trend of an association between informal caregiving and being at LDL cholesterol <100 mg/dl. In contrast, among women there was no association between having an informal caregiver and LDL cholesterol <70 mg/dl or LDL cholesterol <100 mg/dl. Table 4 presents the results of multivariable analysis for informal caregiving and attainment of LDL cholesterol <70 mg/dl overall and according to gender. The relation between informal caregiving and being at intensive goal LDL cholesterol remained significant in men after adjustment.
| Variable | LDL Cholesterol (mg/dl) | On Statin | ||||
|---|---|---|---|---|---|---|
| <100 | <70 | Men | Women | |||
| Men | Women | Men | Women | |||
| Paid vs no caregiver | 1.27 (0.79–2.03) | 1.16 (0.77–1.75) | 1.11 (0.77–1.60) | 0.91 (0.61–1.34) | 1.19 (0.77–1.82) | 1.42 (0.93–2.14) |
| Informal vs no caregiver | 1.26 (0.94–1.68) | 1.05 (0.72–1.55) | 1.35 (1.07–1.70) ⁎ | 1.04 (0.72–1.51) | 0.95 (0.73–1.23) | 0.94 (0.64–1.36) |
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
