El papel de la determinación de un marcador de resorción, el telopéptido carboxiterminal del colágeno I, en la valoración del cumplimiento terapéutico en pacientes tratadas con bifosfonatos orales / The determining role of a resorption marker,carboxyterminal telopeptide of collagen I,in assessing therapeutic compliance inpatients treated with oral bisphosphonates

Objetivo: Se estima que al año entre el 50-60% de los pacientes tratados con fármacos para la osteoporosis son incumplidores. Disponemos de diferentes métodos indirectos de valoración del cumplimiento. Nuestro objetivo es testar una única determinación del telopéptido carboxiterminal del colágeno tipo I (CTX) para valorar el cumplimiento en pacientes tratadas con bifosfonatos, de forma aislada o junto al cuestionario de Morinsky-Green. Material y método: Estudio de validación diagnóstica realizado en 10 centros de Cataluña. Mediante muestreo consecutivo se seleccionaron mujeres postmenopáusicas con osteoporosis y tratadas con un mismo fármaco antirresortivo en el último año; se excluyeron aquellas tratadas con un fármaco diferente a bifosfonato, con deterioro cognitivo, enfermedad terminal, o insuficiencia renal avanzada, o fractura en el año previo. Se recogieron datos sobre el diagnóstico de osteoporosis y tipo de tratamiento. Se solicitó analítica con determinación del CTX. Como gold-standard se utilizó la tasa de posesión de medicación (Medication Possession Ratio, MPR). Mediante metodología de la curva ROC se estableció el punto de corte teórico del CTX. Se calculó la sensibilidad, la especificidad y los valores predictivos positivos para estimar el cumplimiento terapéutico. Resultados: Se incluyeron 100 pacientes, de las cuales más de la mitad recibían alendronato. Según la MPR, un 70% eran cumplidoras. El valor medio del CTX fue de 0,193±0,146 ng/ml, siendo inferior en las pacientes cumplidoras. Se estableció como punto de corte para valorar el cumplimiento un valor de 0,196 ng/ml. La valoración conjunta del CTX junto al cuestionario de Morinsky-Green presentó mayor capacidad discriminativa. Conclusiones: La realización de una única determinación del CTX (<0,196 ng/ml) junto al cuestionario de Morinsky-Green permite valorar mejor el cumplimiento terapéutico en pacientes tratadas con bifosfonatos

Objective:It is estimated that in one year between 50‐60% of patients treated with osteoporosis drugs are non‐com‐pliant. There are different indirect methods of assessing compliance. Our objective is to test a single determination ofthe carboxyterminal telopeptide of type I collagen (CTX) to assess compliance in patients treated with bisphosphonates,either on its own or together with the Morinsky‐Green questionnaire.Material and method:A diagnostic assessment study was carried out in 10 centers in Catalonia. Through consecutivesampling, postmenopausal women with osteoporosis were selected and treated with the same antiresorptive drug inthe last year. Those treated with a drug other than bisphosphonate, with cognitive impairment, terminal illness, advancedrenal failure or fracture in the previous year, were excluded. Data were collected on the diagnosis of osteoporosis andtype of treatment. Analysis was requested with CTX determination. As a gold standard, the medication possession rate(MPR) was used. Using the ROC curve methodology, the theoretical CTX cut‐off point was established. Sensitivity, spe‐cificity and positive predictive values were calculated to estimate therapeutic compliance.Results:100 patients were included, of which more than half were being treated with alendronate. According to theMPR, 70% were compliant. The mean CTX value was 0.193±0.146 ng/ml. It was lower in the compliant patients. A valueof 0.196 ng/ml was established as a cut‐off point to assess compliance. The joint assessment of the CTX together withthe Morinsky‐Green questionnaire showed greater discriminatory capacity.Conclusions:Carrying out a single determination of CTX (<0.196 ng/ml) along with the Morinsky‐Green questionnaireallows us to more accurately assess the therapeutic compliance in patients treated with bisphosphonates

One and two-year persistence with different anti-osteoporosis medications: a retrospective cohort study.

Adherence to anti-osteoporosis medications is poor. We carried out a cohort study using a real-world population database to estimate the persistence of anti-osteoporosis drugs. Unadjusted 2-year persistence ranged from 10.3 to 45.4%. Denosumab users had a 40% lower risk of discontinuation at 2 years compared to alendronate users. PURPOSE: The purpose of this study was to estimate real-world persistence amongst incident users of anti-osteoporosis medications. METHODS: This is a retrospective cohort using data from anonymised records and dispensation data ( www.sidiap.org ). Eligibility comprised the following: women aged ≥50, incident users of anti-osteoporosis medication (2012), with data available for at least 12 months prior to therapy initiation. Exclusions are other bone diseases/treatments and uncommon anti-osteoporosis drugs (N < 100). Follow-up was from first pharmacy dispensation until cessation, end of study, censoring or switching. Outcomes are 2- and 1-year persistence with a permissible gap of up to 90 days. Persistence with alendronate was compared to other bisphosphonates, strontium ranelate, selective oestrogen receptor modulators, teriparatide and denosumab. Cox models were used to estimate hazard ratios of therapy cessation according to drug used after adjustment for age, sex, BMI, smoking, alcohol drinking, Charlson co-morbidity index, previous fractures, use of anti-osteoporosis medication/s, oral corticosteroids and socio-economic status. RESULTS: A total of 19,253 women were included. Unadjusted 2-year persistence [95% CI] ranged from 10.3% [9.1-11.6%] (strontium ranelate) to 45.4% [43.1-47.8%] (denosumab). One-year persistence went from 35.8% [33.9%-37.7%] (strontium ranelate) to 65.8% [63.6%-68.0%] (denosumab). At the end of the first year and compared to alendronate users, both teriparatide and denosumab users had reduced cessation risk (adjusted HR 0.76, 95% CI 0.67-0.86 and 0.54, 95% CI 0.50-0.59 respectively) while at the end of the second year, only denosumab had a lower risk of discontinuation (adjusted HR 0.60, 95% CI 0.56-0.64). CONCLUSIONS: Unadjusted 2-year persistence is suboptimal. However, both teriparatide and denosumab users had better 1-year persistence and only denosumab had 2-year better persistence compared to alendronate users. Unmeasured confounding by indication might partially explain our findings.