Objective
The purpose of this study was to determine whether an electronic prescription for over-the-counter calcium supplements increases compliance.
Study Design
Two hundred forty-five patients from 19-50 years of age who underwent annual gynecologic examinations were assigned randomly to either verbal counseling about the use of a calcium carbonate with vitamin D supplement (n = 122) or verbal counseling and an electronic prescription (n = 123). Telephone interviews at 3 and 6 months determined compliance.
Results
Women who received the electronic prescription were significantly more likely to use calcium supplementation than control subjects at both 3 and 6 months. At 3 months, 66.0% of women who received an electronic prescription reported compliance ( P = .001). At 6 months, 57.0% of the participants were compliant ( P = .001). At 6 months, women who were given the electronic prescription were 2.2 times more likely to report having taken the calcium than were control subjects (95% confidence interval, 1.5–3.1).
Conclusion
An electronic prescription for over-the-counter calcium supplements is associated with a significant increase in compliance, compared with verbal counseling alone.
Calcium is the most abundant mineral in the body. It is critical for the maintenance of skeletal structure and appears to have beneficial effects for several nonskeletal disorders such as colorectal cancer, hypertension, and perhaps obesity. Several organizations, which include the Institute of Medicine and the National Institute of Health, have published guidelines that advise women who are ≤50 years old to consume 1000 mg/day of calcium. Although, in the 2005 Dietary Guidelines for Americans, the US Departments of Health and Human Services and Agriculture advisory committees noted that 3 cups of milk or its equivalent should provide the adult daily calcium goal, most women do not achieve the recommended daily allowance for calcium. According to the US Department of Agriculture Continuing Survey of Food Intakes, >70% of women who are >20 years old are not meeting their recommended daily calcium intake. There is a need for improved calcium intake to meet the recommended daily allowance; however, little information is available in the medical literature on how clinical providers can increase calcium compliance.
Calcium supplements are over-the-counter products. Typically, clinicians provide patients with verbal or written information about the benefits of dietary calcium and, if patients have inadequate dietary calcium intake, counsel those patients to use calcium supplements. The purpose of this study was to determine whether an electronic prescription for an over-the-counter (OTC) calcium supplement that was provided to patients during their annual gynecologic examination increases compliance at 3 and 6 months, compared with physician counseling alone.
Materials and Methods
The trial included women who attended a general obstetrics and gynecology faculty practice that was affiliated with Florida Hospital Orlando between March 2007 and September 2008. The Florida Hospital institutional review committee approved this study.
This faculty practice completes approximately 26,000 outpatient visits per year. The practice implemented an electronic medical record (EMR) system approximately 5 years ago (2006 version; Epic Systems Corporation, Verona, WI). Physicians use the EMR system to document patient visits, review laboratory and imaging studies, and write electronic prescriptions. The prescriptions are printed on a standard-size prescription (14 × 11 cm) and handed to patients before they leave the practice.
All women who were cared for by the study authors were screened for potential eligibility before they completed an annual “well woman” gynecologic evaluation. Women were offered participation in the study only if they were between 19 and 50 years old, if they did not meet exclusion criteria, and after they gave written informed consent. Women in this age range were chosen to participate because most patients who obtained annual gynecologic examinations in our practice are in this age range. Exclusion criteria included current calcium usage, pregnancy, non-English speaking, use of thyroid replacement medication, or a history of hypercalcemia or kidney stones. To prevent bias, researchers described the study as an evaluation of OTC medications at baseline and 3 and 6 months, without specific mention of calcium supplementation.
After written consent, the physical examination was performed in the usual fashion. The researcher then recorded each OTC medication used by participants along with demographic information on a data abstraction form that had been designed for this trial.
After completion of the annual gynecologic examination, all participants received a brief, verbal discussion of the benefits and risks of calcium supplementation using a prearranged script that was designed to reduce variability between researchers. All participants were given advice to use 1 brand of calcium (Os-Cal 500 mg with Vitamin D, 1 pill twice daily with meals; GlaxoSmithKline, St. Louis, MO). We chose this brand, rather than a generic formulation because Os-Cal is available in every area pharmacy that was surveyed and because patients who are given an option to purchase a generic formulation may have struggled to identify the correct type and dosage without the brand identifier. Those patients who met study criteria were assigned randomly to the study or control arm by opaque sealed envelopes that were numbered with a sequence that was produced by a computerized random number generator ( Figure ). Then the women in the control group completed their visit; those women in the intervention group were given an electronic prescription for the calcium carbonate product with the EMR system and told to bring this prescription to the pharmacy to help locate this brand and that this is an OTC product not covered by commercial prescription plans. The computer-generated prescription was a typed prescription for a 160-count bottle. Each prescription contained the following text: “Take one (1) Os-Cal 500/D pill by mouth twice a day (with meals). Bring this prescription with you to the pharmacy to obtain this OTC medication and when you obtain refills. Refill when bottle nears empty.” Each prescription contained the prescribing physician’s printed name, license number, and signature. One physician, who was blinded to the subject’s enrollment status and preenrollment OTC medication use, contacted each participant by telephone at 3 and 6 months after enrollment. Using a predesigned brief script, each participant was queried about current OTC medication usage without specific mention of calcium supplements.
Our main hypothesis was that the proportion of participants who reported calcium intake at the 6-month follow-up visit would be higher in the group of women who received the electronic prescription than in the group who received only verbal counseling about calcium supplementation. Thus, our primary outcome was defined as the proportion of women who reported OTC calcium intake at 6 months. Reported calcium intake at 3 months was a secondary outcome in this study; with the goal of determining whether compliance persisted from 3-6 months. We performed an a priori sample size calculation using a power of 0.8 (type II error, 0.20) and type I error of 0.05. By reviewing a smaller set of patients at our practice, we estimated patient compliance with verbal recommendations to take calcium in our study population of 40%. Assuming that a written prescription for calcium would improve compliance by 50% over baseline, which is an overall calcium compliance rate of 60%, this yielded a minimum sample size of 214 women (107 in each arm). Anticipating a lost to follow up rate of approximately 15%, we enrolled 246 patients (123 in each study arm).
All data were analyzed with STATA statistical software (version 10; Stata Corporation, College Station, TX) by 1 of the authors (G.L.). Descriptive statistics were used to identify missing data and to describe participant characteristics. For describing baseline demographic characteristics, we used frequencies, percentages, means, and standard deviations. Potential differences between the 2 study groups were analyzed with the use of Pearson X 2 tests for categoric variables and t tests for continuous variables. A probability value of < .05 was used to determine statistical significance in these comparison analyses. Risk ratios and 95% confidence intervals (CIs) were used to compare the differences of our categoric primary outcomes.
Results
A total of 1145 patients who appeared for annual gynecologic examinations between the ages of 19 and 50 years were screened for study inclusion. Of these, 900 patients were excluded ( Figure ), and 246 patients were enrolled. Of the 246 enrolled patients, 1 woman decided not to participate on the same day of enrollment, and 43 women (17.5%) were lost to follow up. Among the women who were lost to follow up, 1 woman became pregnant before completion of the study, and 42 women could not be contacted or no longer wished to participate when contacted. Therefore, a total of 202 women completed the study at 6 months (102 in the control group and 100 in the intervention group).
Baseline demographic characteristics are presented in the Table . Of the 245 women who agreed to enroll in the study, >73.9% were white; 13.5% were African American, and <6.5% were Hispanic/Latina. Most participants, nearly 95%, were insured. No statistically significant differences were detected in body mass index, insurance status, and ethnicity between the 2 study groups at enrollment or at completion of the study. At enrollment, the control group was older than the study group (34.7 vs 32.6 years), but this difference was not detected at the completion of the study. None of the women reported any problems or adverse events from participation in the study. Compliance with clinician recommendation was defined as reporting OTC calcium intake at 3 and/or 6 months.
