A retrospective case series study conducted in a public primary care clinic of KCC of HAHK.
Setting of the Multidisciplinary Osteoporosis Clinic (MOC)
Patients with confirmed osteoporosis or osteoporosis related conditions such as history of fragility fractures were referred to MOC for further management. The referring source was mainly from different general outpatient clinics (GOPCs) of KCC and other primary care providers in Hong Kong. This multidisciplinary clinic was specially designed to cater the needs of osteoporotic patients.
Patients referred to the clinic were invited to a Community Based Specialty Nursing Session which included a comprehensive osteoporosis management health talk and an individual counselling session. Fracture risk assessment tool (FRAX), a scoring system assessing one’s 10-year osteoporotic fracture risk based on individual’s clinical risk factors as well as BMD at the femoral neck , was used and FRAX score was calculated during the session. Advice was given accordingly.
After the nursing educational session, a doctor consultation session was arranged in the following weeks. Doctors conducting the consultation acquired at least fellowship qualification of both Hong Kong College of Family Physicians (HKCFP) and Royal Australian College of General Practitioners RACGP (RACGP). They were also equipped with updated knowledge regarding osteoporosis management. The consultation time was on average 15 minutes per patient, which was longer than the 7-minute consultation time in GOPC. This was to ensure sufficient time had been given to attending doctors to convey necessary pharmacological and non-pharmacological advice, and to provide quality medical assessment and management. 
Bisphosphonates are recommended as first line treatment in most guidelines including National Osteoporosis Foundation (NOF) guidelines and the American Association of Clinical Endocrinologists (AACE) guidelines [10, 11]. Oral alendronate is the only pharmacological agent that can be reimbursed in HAHK for patients with history of osteoporotic fracture. Therefore, guideline directed medical therapy, namely alendronate was regularly prescribed in our clinic.
DEXA scan was performed upon joining MOC, i.e. baseline DEXA scan. It was repeated after 1-2 years of initiation of pharmacological treatment and every 2 years thereafter if BMD had been stabilized or improved, compatible with most guidelines’ recommendation including NOF guidelines, AACE guidelines and the International Society for Clinical Densitometry (ISCD) guideline [10, 11, 12]. To ensure uniform data comparisons, patients were urged to have their DEXA scans repeated in the same diagnostic center, assuming the same DEXA machine was used. Doctor follow up appointment was arranged depending on clinical needs.
Allied health services such as dietitian counselling, physiotherapy and occupational therapy were also available upon doctor’s referral.
All osteoporotic patients, coded by International Classification of Primary Care (ICPC) L95 (osteoporosis), who had attended MOC of KCC of the HAHK from 1 January 2015 to 31 December 2018.
- Osteopenia patients
- Osteoporosis patients due to secondary causes such as osteoporosis due to endocrine diseases or corticosteroid use
- Osteoporosis patients who had been followed by other specialists or private doctors
- Osteoporosis patients who had been treated with osteoporosis medication before joining MOC, Osteoporosis medication means any type of bone antiresorptive and anabolic drugs, not including vitamin D and calcium supplement
- Osteoporosis patients who had no baseline DEXA scan
- Osteoporosis patients who had no interval DEXA scan
Definition of Osteoporosis
Dual X-ray absorptiometry (DEXA) is the gold standard and most precise technique for BMD measurement . The difference between the patient’s BMD and mean BMD of young female adult, divided by the standard deviation (SD) of the reference population, yields the T-score. A DEXA T-score of -1.0 or above was regarded as normal. While a DEXA T-score between -0.1 to -2.5 was regarded as osteopenia. Osteoporosis was defined as DEXA T-score of ≤-2.5, according to World Health Organization .
Determination of variables
The recruited patient’s age, gender, ethnicity, smoking status, drinking status, body mass index (BMI), family history of fracture, past history of fracture, other past medical history or co-morbidities, menopausal status (for female), age of menopause, FRAX score were retrieved from nursing consultation notes of Clinical Management System (CMS) of HAHK. The BMI was calculated as body weight (kg)/body height2 (m2). The patient was considered a smoker if he/she was an active smoker or had quit smoking within 6 months. Baseline blood test including complete blood count, liver function test, calcium level, phosphate level and thyroid function test of patients were collected from the CMS of HKHA.
Baseline and 2-year interval DEXA T-scores were collected. Baseline DEXA T-score was the T-score of DEXA scan performed upon joining MOC, within one year before or after first doctor consultation. The 2-year interval DEXA T-score was the T-score of the DEXA scan performed at or nearest to 2 years after joining MOC. The serial interval T-scores of those who had completed 5 years of bisphosphonate were collected. These data were retrieved from doctor consultation notes from CMS of HKHA. If in any doubt, the original copy of DEXA report was referred to. The occurrence of new osteoporotic fractures documented in consultation notes was also recorded.
Primary and Secondary outcome
- Changes in DEXA T-score of recruited osteoporotic patients after two years of management at MOC.
- Subgroup analysis: 2-year interval DEXA T-score changes among patients with or without history of fragility fracture; and among patients with or without pharmacological treatment
- Serial interval DEXA T-score changes of recruited patients who had completed 5 years of bisphosphonate
Secondary outcome: The occurrence of new osteoporotic fracture of recruited osteoporotic patients
Sample size calculation
From previous studies, the mean BMD difference between treatment and non-treatment group was 0.03 g/cm2, with a SD of 0.13 [15,16]. At 95% confidence level and a power of 0.8, with the use of paired sample T test for sample size calculation, the sample size required is 147. To allow the room for data exclusion (~20%), totally 186 patients were included into the data analysis.
All data were entered and analyzed using computer software (SPSS version 23, Chicago, IL, US). Categorical variables were presented as frequencies and percentages. Continuous variables were presented as mean, plus standard deviation. Paired Student’s t test was used to analyze continuous variables. All statistical tests were two-sided, and a P value of <0.05 is considered significant.