Osteoporosis in Primary Care: Who to Screen, Reading the T-Score, FRAX and First-Line Treatment

Osteoporosis questions on the FNP and AGNP exams follow a fixed chain: who gets a DXA, what the T-score means, whether FRAX pushes an osteopenic patient into treatment, and which drug comes first. The 2025 USPSTF statement recommends screening all women 65 and older and postmenopausal women younger than 65 who are at increased risk. A T-score of -2.5 or lower, or a hip or vertebral fragility fracture, means osteoporosis and warrants treatment, and an osteopenic T-score warrants treatment when the US FRAX 10-year risk is at least 3 percent for hip fracture or 20 percent for major osteoporotic fracture. First-line therapy for most patients is an oral bisphosphonate, with calcium, vitamin D, exercise and fall prevention for everyone.

The sections below follow that chain using the USPSTF 2025 statement, the Bone Health and Osteoporosis Foundation (BHOF) 2022 clinician's guide and the AACE 2020 postmenopausal osteoporosis guideline.

Who to screen

The USPSTF statement applies to adults without prior fragility fractures or conditions that weaken bone; those patients need evaluation, not screening. For younger postmenopausal women, the USPSTF expects a formal risk tool (FRAX is the one most often used in practice) to decide who goes on to DXA. Note the exam trap: USPSTF does not endorse routine screening of men, while BHOF does from age 70.

Clinical risk factors to look for

The FRAX inputs double as the risk factor list the exam uses: age, sex, low BMI, prior fragility fracture (including vertebral fractures found on imaging), parental hip fracture, current smoking, alcohol of 3 or more drinks a day, oral glucocorticoids at 5 mg a day of prednisone or equivalent for more than 3 months, rheumatoid arthritis, and secondary osteoporosis (for example type 1 diabetes, untreated hypogonadism or premature menopause, chronic malnutrition or malabsorption, chronic liver disease). Fall risk, height loss and kyphosis complete the history.

Reading the DXA

DXA reports two scores. The T-score compares the patient's BMD with a young-adult reference population and is used to diagnose osteoporosis in postmenopausal women and men 50 and older. The Z-score compares the patient with an age-matched population and is used in premenopausal women and younger men, where a low result means "below the expected range for age" and prompts a search for secondary causes rather than a diagnosis of osteoporosis.

A clinical diagnosis does not always need a DXA number. AACE 2020 allows a diagnosis of osteoporosis with a low-trauma hip or vertebral fracture regardless of BMD, and with osteopenia plus a fragility fracture of the proximal humerus, pelvis or distal forearm, or osteopenia with a FRAX probability above the treatment threshold.

FRAX: when osteopenia becomes a treatment decision

FRAX estimates the 10-year probability of a hip fracture and of a major osteoporotic fracture (clinical vertebral, hip, forearm or proximal humerus) from the clinical risk factors plus femoral neck BMD. It is designed for adults 40 to 90 who are not on osteoporosis treatment. In the United States, BHOF uses these treatment thresholds for patients with a T-score between -1.0 and -2.5 at the femoral neck or total hip:

• 10-year hip fracture probability of 3 percent or higher, or
• 10-year major osteoporotic fracture probability of 20 percent or higher.

Either threshold alone is enough. A vignette with hip risk 3.2 percent and major fracture risk 14 percent is a treatment patient; candidates who wait for both numbers miss it. FRAX can underestimate risk with high-dose glucocorticoids, a large difference between spine and hip T-scores, or frequent falls, which are not captured as inputs.

Vertebral imaging

Vertebral fractures are often silent and change both the diagnosis and the drug choice. BHOF recommends considering a lateral spine radiograph or DXA vertebral fracture assessment for:

• All women 65 and older and all men 80 and older with a T-score of -1.0 or lower.
• Men 70 to 79 with a T-score of -1.5 or lower.
• Postmenopausal women and men 50 and older with a fracture in adulthood, historical height loss of 1.5 inches or more, prospective height loss of 0.8 inches or more, recent or long-term glucocorticoid use, or a condition such as hyperparathyroidism.

Ruling out secondary causes

Before starting therapy, a basic laboratory evaluation looks for treatable contributors: CBC, a metabolic panel with calcium, phosphorus, albumin, creatinine and alkaline phosphatase, 25-hydroxyvitamin D and TSH. Selected patients need PTH, 24-hour urine calcium, celiac serology, serum protein electrophoresis or, in men, testosterone. A Z-score that is low for age, fractures on treatment or bone loss out of proportion to age all raise suspicion of a secondary cause. Hypocalcemia and vitamin D deficiency must be corrected before a bisphosphonate or denosumab is given.

Who to treat

BHOF 2022 recommends considering pharmacologic treatment in postmenopausal women and men 50 and older with:

The Endocrine Society algorithm summarized in the BHOF guide suggests reassessing low and moderate risk patients in 2 to 4 years.

First-line treatment

Universal measures for everyone

• Calcium: total intake of 1,200 mg a day for women 51 and older and men 71 and older, and 1,000 mg a day for men 50 to 70, preferably from diet with supplements only to fill the gap. Intakes above 1,200 to 1,500 mg a day from supplements add no benefit and may add risk.
• Vitamin D: 800 to 1,000 units a day for adults 50 and older, aiming for a 25-hydroxyvitamin D level of at least 30 ng/mL.
• Exercise: regular weight-bearing and muscle-strengthening activity, plus balance training.
• Fall prevention: vision, footwear, home hazards, medication review (sedatives, orthostatic agents).
• Stop smoking and limit alcohol.

Drug choice

Ibandronate is not recommended when hip and nonvertebral fracture reduction is the goal. Calcitonin is a last resort.

Oral bisphosphonate administration is a reliable exam item: take first thing in the morning with 6 to 8 oz of plain water, at least 30 minutes before food, drink or other medicines (60 minutes for ibandronate), swallow whole and stay upright until after the first food of the day.

Monitoring and treatment duration

• DXA: 1 to 2 years after starting or changing therapy, then at intervals set by the clinical situation; more often in very high risk patients.
• Height: measure at visits; a loss of 0.8 inches or more prompts repeat vertebral imaging.
• Drug holiday: reassess after 5 years of an oral or 3 years of an intravenous bisphosphonate. If the T-score is above -2.5 and there has been no new fracture, a holiday can be considered, with reevaluation every 1 to 2 years. Patients still at high risk continue.
• Denosumab: no drug holiday; stopping it causes rapid bone loss and multiple vertebral fractures, so another antiresorptive follows.
• Adherence: ask about GI symptoms and dosing technique at every visit.

Safety: what to counsel and what to recognize

• Osteonecrosis of the jaw: rare in osteoporosis doses; good oral hygiene and routine dental care, ideally completing major dental work before starting.
• Atypical femur fracture: rare, may be bilateral; new thigh or groin pain on a bisphosphonate or denosumab needs imaging of both femurs.
• Esophagitis: chest pain or painful swallowing on an oral bisphosphonate means stopping and reassessing.
• Hypocalcemia: correct before therapy, especially before denosumab or zoledronic acid.

Referral triggers

• Fracture or significant BMD loss while adherent to therapy.
• Very high fracture risk where anabolic therapy is considered.
• eGFR below 30 to 35, secondary causes such as hyperparathyroidism, or a low Z-score in a younger adult.
• Intolerance of or contraindications to first-line agents.

Patient education

• The goal is preventing fractures, not just improving a number.
• Take the bisphosphonate exactly as instructed; incorrect technique causes both esophageal injury and poor absorption.
• Meet calcium needs mainly through food; add vitamin D as advised.
• Make the home safer and keep up strength and balance exercise.
• Report thigh or groin pain, jaw pain or nonhealing gums, and painful swallowing.
• Do not stop denosumab without a plan.

How the exam tests this

• FRAX misread. Osteopenia with hip risk at or above 3 percent is a treatment patient even if major fracture risk is below 20 percent.
• Wrong screening population. USPSTF does not recommend routine screening of men; a question asking for the USPSTF position on a 72-year-old man expects "insufficient evidence."
• Treating the T-score, missing the fracture. A vertebral compression fracture after minimal trauma means osteoporosis regardless of a T-score of -1.8.
• Wrong first drug. Teriparatide for a new, uncomplicated diagnosis, or calcitonin as first-line, are distractors; very high risk is the exception.
• Administration errors. Taking alendronate with coffee or lying down afterward.
• Denosumab holiday. Stopping denosumab without follow-on therapy is wrong.
• Calcium alone. Calcium and vitamin D support therapy but do not replace it in a patient who meets treatment criteria.

Practice question

A 66-year-old woman has her first DXA. Femoral neck T-score is -2.1 and lumbar spine T-score is -1.7. She has never had a fracture. Her mother had a hip fracture at 78. She does not smoke, drinks 1 glass of wine a week and takes no medications. BMI is 21. US FRAX estimates a 10-year major osteoporotic fracture probability of 16 percent and a hip fracture probability of 3.4 percent. eGFR is 82 mL/min/1.73 m2 and she has no GI symptoms. Which of the following is the most appropriate plan?

• A. Calcium and vitamin D only, with repeat DXA in 2 years
• B. Alendronate 70 mg weekly with calcium and vitamin D intake counseling
• C. Teriparatide daily injection for 2 years
• D. No treatment because the T-score does not meet the definition of osteoporosis

Answer: B. Osteopenia with a 10-year hip fracture probability of 3 percent or higher meets the BHOF treatment threshold even though the major osteoporotic fracture risk is below 20 percent, and an oral bisphosphonate is first-line for a high-risk patient with normal renal function and no GI contraindication. Option A applies universal measures only and misses that either FRAX threshold triggers treatment. Teriparatide (C) is reserved for very high risk patients, such as those with recent or multiple fractures or a T-score below -3.0. Option D uses the T-score alone and ignores the FRAX criteria that apply to osteopenia.

Key points

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