Suboptimal vitamin D screening in older patients withcompromised skeletal healthNahid J. Rianon MD DrPH,1 Kathleen P. Murphy PhD MS GNP-BC,3 Rodrigo Guanlao MD,2

Matthew Hnatow BS,4 Elaine De Leon MD5 and Beatrice J. Selwyn ScD6

1Assistant Professor, 2Postdoctoral Fellow, Department of Internal Medicine/Division of Geriatric and Palliative Medicine, University of TexasMedical School at Houston, Houston, Texas, USA3Adjunct Professor, University of Texas Health Science Center at Houston School of Nursing, Houston, Texas, USA4Medical Student, MSIII, University of Texas Medical School at Houston, Houston, Texas, USA5Resident, PGY3, Department of Family and Community Medicine, University of Texas Medical School at Houston, Houston, Texas, USA6Associate Professor, Epidemiology and Disease Control, University of Texas Houston School of Public Health, Houston, Texas, USA

Keywords

family medicine, geriatric medicine, olderpatients, osteoporosis, primary care, vitaminD screening

Correspondence

Dr Nahid RianonDepartment of Internal MedicineUniversity of Texas Medical School atHouston6431 Fannin St. #MSB 5.111HoustonTX 77030USAE-mail: Nahid.J.Rianon@uth.tmc.edu

Accepted for publication: 15 October 2013

doi:10.1111/jep.12099

AbstractsRationale, aims and objectives Increasing number of primary care visits for osteoporosisby older patients combined with new vitamin D screening recommendations necessitateprimary care providers (PCPs) to identify and screen at-risk patients. We described preva-lence and determinants of vitamin D screening among older patients treated forosteopoenia, osteoporosis and related fractures in academic outpatient primary care clinics(family medicine and geriatric medicine) in Houston, TX.Methods Electronic chart review collected data on patients ≥50 years old from January2008 to December 2010. Orders for serum 25-hydroxy vitamin D indicated vitamin Dscreening. Differences in patient characteristics were described between the groups withand without vitamin D screening. Age, body mass index, racial/ethnic background, bone-promoting medication (BPM) use and clinic types (family medicine versus geriatric medi-cine) were determinants for vitamin D screening in the regression analysis.Results Patients were mostly women (95%), Caucasian (65%) and had a mean age of69 ± 12 years. Twenty-two per cent of the family medicine clinic patients (total n = 78) and51% of the geriatric medicine clinics patients (total n = 70) were screened. Older age (oddsratio, 0.94 confidence interval = 0.90–0.99) and BPM use (2.58, 1.03 to 6.45) were sig-nificant positive determinants for vitamin D screening.Conclusions In primary care clinics, vitamin D screening remains low among patientsdiagnosed with osteopoenia, osteoporosis and fractures. In light of new guidelines, subop-timal screening in the vulnerable older patients is disturbing. We recommend increasedPCPs’ awareness about vitamin D screening guidelines for improving skeletal health inolder patients.

IntroductionDeficiency of vitamin D, an essential nutrient for skeletal health,places older patients at high risk for age-related bone loss leadingto osteopoenia, osteoporosis and associated fractures [1–12]. Onein 2 women and 1 in 4 men 50 years or older in the United Statesis estimated to experience an osteoporotic fracture in their life time[7]. Decreased quality of life and the incurred health care costattributed to osteoporosis and related fractures in older patientsgenerated interest in improved screening guidelines for skeletalhealth risk factors, for example vitamin D [7–9,13–15].

In older adults, impairment of calcium absorption and negativecalcium balance is attributed to vitamin D deficiency [16]. Thereare distinct risk factors found in the geriatric population that con-tribute to calcium imbalance and promote osteoporosis. These riskfactors include multiple medical co-morbidities, medications suchas proton pump inhibitors, age-related decrease in intestinalabsorption, decreased mobility and reduced conversion of vitaminD to its active metabolite [7–9,16,17]. Despite controversy aboutguidelines for evaluation and supplementation [18,19], consensusfrom most observational studies as well as recommendation fromboth the Endocrine Society Clinical Practice Guidelines and the

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recent Institute of Medicine report favour screening for vitamin Dlevels in at risk patients, for example those with older age (≥50years) and those with osteopoenia, osteoporosis and related frac-tures [1–12]. Competing chronic disease priorities are barriers toaddressing skeletal health by primary care providers (PCPs)during short outpatient visits [20–24]. Yet a recent increase innumber of primary care visits for osteoporosis by older patients[25] makes it imperative that PCPs are appropriately screeningvitamin D levels in at risk patients. The increasing trend of osteo-porosis care by PCPs [25] brings about concern for potentialinadequate management of osteoporosis specifically when treatedby non-specialty PCPs [26,27]. This, along with new vitamin Dscreening guidelines [18,19] signify need to revisit vitamin Dscreening in at risk older patients seeking care from their PCPs forcompromised skeletal health.

Routine checking of calcium and creatinine in clinical settingsand their metabolic association with vitamin D levels may influ-ence management of patients with abnormal calcium andcreatinine since these patients usually get referred to specialtyclinics, for example endocrinology or nephrology and are notmanaged by PCPs [28,29]. Most studies discussing vitamin Ddeficiency in older adults focused on general prevalence of defi-ciency and lack critical information on screening status by physi-cian type (PCPs or non-PCPs) or appropriateness of the patients tobe managed by PCPs based on their metabolic or renal functionstatus [1–6,8,9,30–32]. With an aim to truly assess prevalence ofscreening in at-risk older patients appropriate for primary careclinics, we investigated prevalence of vitamin D screening amongpatients with normal serum calcium and renal function by serumcreatinine levels. In this study, we described the prevalence ofvitamin D screening in patients aged 50 years or older, diagnosedwith osteopoenia, osteoporosis and related fractures in outpatientprimary care clinics including family medicine and geriatricclinics in an academic programme in Houston, TX. We furtherinvestigated determinants of vitamin D screening among the samestudy patients.

Methods

Population

Data were collected on 157 patients (n = 80 family medicineand n = 77 geriatrics) ≥50 years old receiving treatment forosteopoenia, osteoporosis and related fractures from January 2008to December 2010 in family medicine and geriatric clinics inHouston, TX. The International Classification of Diseases, NinthRevision, Clinical Modification code was utilized to identifypatients with osteoporosis, osteopoenia, vertebral or hip fracturelisted as an assessed clinic visit health problem between January 1,2008 and December 31, 2010. Diagnoses were confirmed by elec-tronic medical review of the history of present illness. Fracturesassociated with motor vehicle accident or high impact traumawere excluded from our study. Only the first visit for the sameassessed diagnosis within the study period was included in theanalysis. The Committee for Protection of Human Subjects of theUniversity of Texas Health Science Center at Houston approvedthe study.

Data collection

Electronic medical record data collection was conducted by atrained research assistant. Orders for serum 25-hydroxy vitamin Dlevels [18,33] within a year before or a year after the visit dateindicated positivity for vitamin D screening test. Extracted infor-mation for data analysis included age, gender, height, weight, bodymass index (BMI), gender, race/ethnicity, current status forsmoking and alcohol use, serum levels of calcium and creatinine,use of calcium/vitamin D supplements and medication to treatosteoporosis [defined as bone-promoting medication (BMP)], andcommon chronic co-morbid conditions (hypertension, diabetesmellitus, any thyroid problem, depression, arthritis).

Data analysis

Nine patients were excluded because of abnormal levels (based onstandard laboratory practice used by the participating clinics) ofcalcium (below 8.4 and above 10.4 mg/dL) and creatinine above1.4. A total of 148 patients (78 from family medicine and 70 fromgeriatric medicine clinic) were included in our final analysis.Using standard cross-tabulations, the chi-square statistic providedstatistical significance testing (P < 0.05) to describe patient char-acteristics by vitamin D screening status (yes or no). A logisticregression analysis was conducted to investigate determinant riskfactors for vitamin D screening. Age, clinically relevant riskfactors for vitamin D deficiency and osteoporosis, for exampleBMI as a measure of obesity, racial/ethnic background (minoritiesare known to be at greater risk of vitamin D deficiency) [6,34], useof BPM, and clinic type (family medicine versus geriatric clinic)because of its significant relationship with vitamin D screeningin bivariate analysis, were included in the logistic model. Sevenout of 8 patients with ‘fall’ as a diagnosis were from the geriatricclinic and so were excluded from the logistic model because ofco-linearity. We report odds ratios and their 95% confidence inter-vals for a positive screening status.

ResultsThe study patients had a mean age (±standard deviation) of 69(± 12) years, was predominantly female (95%) and Caucasian(65%). Approximately, 20% were African American and 15% rep-resented other racial/ethnic backgrounds (including Hispanics,Asian Indian). We combined all patients from non-Caucasianethnic/racial groups and called the group ‘minority’. Similar per-centages of patients (total n = 148) were recruited from each clinicwith 53% from family medicine. About half (49%) of the patientsfrom the geriatrics clinic and 78% from the family medicine clinicwere not screened for vitamin D level.

Table 1 describes patient characteristics by vitamin D screeningstatus (yes or no). Age, clinic type (family medicine versus geri-atric medicine) and having a fall in the past year were statisticallysignificantly associated with vitamin D screening status in thebivariate analysis (Table 1).

The majority of patients (87.5%) who reported a fall were fromthe geriatric clinic. The majority of patients (89.2%) with pre-scribed BPM were also reporting taking calcium and vitamin Dsupplements. Therefore, to avoid co-linearity, both falls and useof calcium and vitamin D supplements were excluded from the

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logistic regression model. Older age and taking BPM becamestatistically significant determinants of vitamin D screening forour study patients after controlling for other determinants.(Table 2).

DiscussionWe report suboptimal screening for vitamin D levels in at riskpatients who were seen for compromised bone health in twoprimary care clinics including family medicine and geriatric out-patient clinics in Houston, TX. Although screening was betteramong geriatric patients, only about half of the geriatric clinic

patients were screened for vitamin D levels. Older age and apositive history of taking BMP were determinants of beingscreened for vitamin D. Our analysis is consistent with the publichealth concern for under-recognition of the need to screen forvitamin D levels among older patients at risk of osteoporosis andfractures [18,19,30].

Vitamin D is needed for both bone mineralization and maintain-ing mineral homeostasis to prevent mobilization of stored calciumfrom bones [11]. Low vitamin D levels are associated withdecreased intestinal absorption, and reduced conversion to itsactive metabolite in older people who are also at risk of osteopo-rosis and related fractures because of their age [7–9,16,17]. Fallsassociated with low vitamin D levels adds to the burden of fracturein older patients [2,8,10–12,31]. Because of low toxicity with largesafety margins, daily supplementation with 800–1000 IU of D isoften recommended in healthy adults without having to screen forserum vitamin D levels [18,19]. However, the daily supplementa-tion dose may not be sufficient to bring the levels to desiredrecommended levels if the baseline levels were already deficient(<20 ng mL−1) [18,19]. Adequate vitamin D of 30 ng mL−1, asrecommended by the Endocrine Society Clinical Practice Guide-lines [18], is necessary for maintaining a normal skeletal homeo-stasis and provide a metabolic state for treatment success withpharmacologic interventions [35]. As a consequence, the Endo-crine Society Clinical Practice Guidelines recommend screeningfor deficiency and appropriate supplementation of vitamin D forolder patients at risk of worsening skeletal health [11,18,19,30,33].A prevalence of only 36% screening for vitamin D among the olderpatients in our study is alarmingly low and quite disturbing in lightof national guidelines for screening. It is recommended that

Table 1 Patient characteristics by vitamin D screening status (yes/no) in participants 50 years and older visiting primary care clinics forosteopoenia, osteoporosis and related fractures

Patient characteristics Category Unit

Vitamin D screening status

P-valueYes Non = 53 (36%) n = 95 (64%)

Age Years Mean ± SD 75 ± 12 67 ± 12 <0.01Body mass index kg/cm2 Mean ± SD 25 ± 5 25 ± 5 0.89Gender Men n (%) 4 (8%) 4 (4%) 0.39

Women n (%) 49 (92%) 91 (96%)Clinic specialty Family medicine n (%) 17 (32%) 61 (64%) <0.01

Geriatrics n (%) 36 (68%) 34 (36%)Race/ethnicity Caucasian n (%) 30 (65%) 51 (65%) 0.94

Others n (%) 16 (35%) 28 (35%)Current smoking Yes n (%) 5 (15%) 9 (13%) 0.77Current alcohol use Yes n (%) 11 (38%) 24 (38%) 0.96Vitamin D/calcium supplements Yes n (%) 47 (89%) 89 (94%) 0.28Serum calcium level mg/dL Mean ± SD 9.5 ± 0.5 9.4 ± 0.4 0.25Serum creatinine level mg/dL Mean ± SD 0.9 ± 0.2 0.9 ± 0.2 0.59Bone promoting medication Yes n (%) 28 (53%) 50 (53%) 0.98Falls last year Yes n (%) 5 (20%) 3 (5%) 0.02Hypertension Yes n (%) 31 (58%) 50 (53%) 0.49Diabetes mellitus Yes n (%) 6 (11%) 7 (7%) 0.41Thyroid diseases Yes n (%) 10 (19%) 12 (13%) 0.30Depression Yes n (%) 14 (26%) 15 (16%) 0.11Arthritis Yes n (%) 6 (11%) 11 (12%) 0.96

Table 2 Determinants of vitamin D screening status (yes versus no)in patients 50 years and older visiting primary care clinics anddiagnosed with osteopoenia, osteoporosis and related fractures

DeterminantsOdds ratio with 95%confidence interval (n = 122)

Age 0.95 (0.90 to 0.99)*Body mass index 0.97 (0.89 to 1.04)Race/ethnicity (Caucasian versus other) 1.20 (0.51 to 2.81)Bone promoting medications (taking

versus not taking)2.59 (1.03 to 6.45)*

Clinic type (family medicine versusgeriatric medicine)

0.44 (0.13 to 1.47)

*P < 0.05.Each determinant variable in the logistic regression analysis is adjustedfor all others in the model.

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physicians be educated and made aware of the current EndocrineSociety Clinical Practice Guidelines for vitamin D screening in atrisk patients with compromised skeletal health [18]. Physicianawareness and action is needed to improve the poor managementstatus of osteoporosis in the vulnerable elderly.

Previous studies discussed both the need for increased testing[33] and the levels of vitamin D deficiency in ambulatory, acuteand inpatient care [1,24,30,32,33] settings; however, the studiesfocused on the prevalence of deficiency and not on screeningpractices or rates of screening by PCPs. In our study, the preva-lence of screening is low, which is consistent with one inpatientstudy reporting a similarly low prevalence (37%) in older (>50years) hip fracture patients [36].

Our study verifies low screening prevalence by PCPs forvitamin D levels. Strong policies are needed to promote vitamin Dscreening in at risk patients seen in primary care clinics. The sizeof the geriatric population in the United States is increasing, andthey are seeking osteoporosis care from their PCPs. However,statistics indicate only 20% of fracture patients are being followedand treated for osteoporosis after admission for osteoporotic frac-tures [37]. Every year, the United States spends about $22 billionfor osteoporosis related health care cost [13]. Prevention of boneloss and fractures by appropriately identifying patients at risk orthose suffering from compromised skeletal health would save pre-cious health care dollars and relieve a growing burden of poorskeletal health among the elderly.

In our study, patients seen in the geriatric clinic had a betterscreening rate compared to the family medicine clinic. However,only 50% were screened in the geriatric clinic, which is notoptimum. While a greater percentage of screening by geriatricianswho typically care for much older patients may indicate influencefrom advanced training in health care for the elderly, an overalllow prevalence in our study may indicate a lack of awareness inPCPs including geriatricians about vitamin D screening in theolder patients. Our study did not look into physicians’ awarenessor perspective or knowledge about vitamin D screening in olderpatients at risk of bone loss and fracture. Inadequate screeningrates points to a need to investigate physician factors that arehindering appropriate management of osteoporosis and associatedfractures in at risk patients.

The higher probability of screening in patients who aretaking BMP in our study indicates physicians’ understand skel-etal risk when patients are already being treated for osteoporosisor fractures. A history of taking medication to promote or treatosteoporosis is certainly a marker of compromised skeletalhealth. Yet, a low prevalence of screening in patients seekingcare for osteopoenia, osteoporosis and fractures regardlessof their treatment status is unsettling in the context of treatingat risk patients in our study. Lack of PCPs ability to recognizepresence of osteopoenia, osteoporosis and fracture as riskfactors may lead to low vitamin D screening in at risk olderpatients.

Our study is novel in that we report vitamin D screening byPCPs in at risk older patients who are otherwise normal in meta-bolic and renal function status with normal levels of calcium andcreatinine. Thus, these study patients were not referred to thespecialty clinics, making their ‘at risk’ nature harder to discern,and yet they remain at risk of being inappropriately treated byeither PCPs or geriatricians.

Vitamin D screening was positive only if it was documented inthe chart within the 12 months before or after the visit date in ourstudy. While we may have missed screenings in some patients, wedid not find any additional information about concern or plan forvitamin D supplementation from the history of present illness andplan sections of the electronic chart for the patients. A cross-sectional analysis with retrospective chart review with a smallsample size is a limitation of our study. We warrant caution whileinterpreting results for other populations who are not served byPCPs in a big city like Houston in an academic programme.

Prevention and maintenance of health with recommendedscreening and monitoring is the key for improving care for chronicdiseases, for example osteoporosis, through primary care [20,38];which mainly takes place in an outpatient setting. Evaluation andmaintenance of vitamin D levels are thus important primary careactivities for improving skeletal health of our elderly patients.Clinical practice challenges such as polypharmacy, low priority onthe list of multiple co-morbidities, time-constraints because ofregulatory issues, belief and attitude towards diagnostic tools andlimited available treatment options for osteoporosis managementhave been reported by primary care physicians [20–24]. Patient-centred medical homes (PCMH) are gaining popularity with estab-lished reports of success in improving chronic care while facingcommon challenges and barriers delivering primary care [39,40].Our results suggest a need for focus on actions to improve skeletalhealth in at risk older patients, especially given the increasedprevalence of outpatient primary care visits for osteoporosis man-agement [25] and the increased concern about health care cost andquality of life because of osteoporosis and related fractures in theelderly [7–9,13–15]. Perhaps, a focus as a special skeletal healthclinic or making it part of a chronic care model under PCMHwould improve osteoporosis care in the United States.

We report very low vitamin D screening among older patientswith compromised skeletal health. While older age and treatmentfor osteoporosis with medication were positive determinants forvitamin D screening in our study, we recommend increasedemphasis on physicians’ education to improve knowledge, aware-ness and practice that would optimize osteoporosis managementthe elderly patients.

AcknowledgementsThis research was supported by funding from the Texas Academyof Family Physicians (TAFP) and Herzstein Foundation.

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