Data from: Associations between polypharmacy and treatment intensity for hypertension and diabetes: a cross-sectional study of nursing home patients in British Columbia, Canada

Objectives: Describe nursing home polypharmacy prevalence in the context of prescribing for diabetes and hypertension and determine possible associations between lower surrogate markers for treated hypertension and diabetes (over treatment) and polypharmacy. Design: Cross sectional study. Setting: 6 nursing homes in British Columbia, Canada. Participants: 214 patients, residing in one of selected facilities during data collection period. Primary and secondary outcome measures: Polypharmacy was defined as >=9 regular medications. Over treatment of diabetes was defined as being prescribed at least one hypoglycemic medication and a glycosylated hemoglobin (A1c) <=7.5%. Over treatment of hypertension required being prescribed at least one hypertension medication and having a systolic blood pressure (SBP) <=128 mmHg. Polypharmacy prescribing, independent of over treatment, was calculated by subtracting disease specific medications from total medications prescribed. Results: Data gathering was completed for 214 patients, 104 (48%) of whom were prescribed >=9 medications. All patients were very frail. Patients with polypharmacy were more likely to have a diagnosis of hypertension (p=.04) or congestive heart failure (p=.003) and less likely to have a diagnosis of dementia (p=.03). Patients with over treated hypertension were more likely to also experience polypharmacy (RR 1.77 (1.07-2.96), p=.027). Patients with over treated diabetes were prescribed more non-diabetic medications than those with a higher A1c (11.0 ±3.7 versus 7.2 ±3.1, p=.01).
Conclusion: Over treated diabetes and hypertension may be quite prevalent in nursing home patients and the presence of polypharmacy is associated with more aggressive disease treatment. Further study of interventions designed to reduce over treatment of hypertension and diabetes is needed to fully understand the potential links between polypharmacy and potential of harms of disease-specific over treatment.

研究目标：本研究旨在描述疗养院患者在糖尿病与高血压处方场景下的多重用药（polypharmacy）患病率，并探究经治疗的高血压与糖尿病的替代标志物偏低（即疾病过度治疗）与多重用药之间的潜在关联。
研究设计：横断面研究。
研究地点：加拿大不列颠哥伦比亚省的6家疗养院。
研究对象：数据收集期间入住所选疗养院之一的214例患者。
主要与次要结局指标：将多重用药定义为同时服用≥9种常规药物。糖尿病过度治疗定义为：处方至少1种降糖药物且糖化血红蛋白（glycosylated hemoglobin，A1c）≤7.5%。高血压过度治疗定义为：处方至少1种降压药物且收缩压（systolic blood pressure，SBP）≤128 mmHg。通过从总处方药物中扣除疾病特异性用药，计算得到与过度治疗无关的多重用药处方情况。
研究结果：本研究共完成214例患者的数据收集，其中104例（48%）患者处方了≥9种药物。所有受试者均为重度衰弱。合并多重用药的患者更常被诊断为高血压（p=0.04）或充血性心力衰竭（p=0.003），而痴呆诊断率更低（p=0.03）。合并高血压过度治疗的患者更易出现多重用药（相对风险RR=1.77，95%置信区间1.07~2.96，p=0.027）。与糖化血红蛋白水平较高的患者相比，糖尿病过度治疗患者的非糖尿病类用药量更多（11.0±3.7 vs 7.2±3.1，p=0.01）。
研究结论：疗养院患者中，糖尿病与高血压的过度治疗可能相当普遍，而多重用药与更积极的疾病治疗方式存在关联。未来需开展针对降低高血压与糖尿病过度治疗的干预研究，以全面阐明多重用药与疾病特异性过度治疗潜在危害之间的关联。