Uric Acid in Primary Hyperparathyroidism: Assessment of Surgical versus Conservative Approach.

Introduction: Although suggested in early papers, the association between primary hyperparathyroidism (PHPT) and hyperuricemia is still debated, as is the potential benefit of parathyroidectomy compared to conservative treatment in serum uric acid (SUA) metabolism. Material and Methods: Our retrospective study of 125 Caucasian PHPT patients with surgical criteria evaluated between 2017 and 2021 at Elias Emergency and University Hospital, Bucharest, Romania aims to describe the characteristics of hyperuricemia in PHPT patients and to assess the differences in SUA levels between 38 surgically cured and 41 conservatively managed patients. Results: Our hyperuricemic PHPT patients (N=34) had significantly higher levels of calcium (11.55[11.05;12.42] vs. 11.2[10.8;11.96], p=.039) than the normouricemic subjects (N=91). At baseline, SUA correlated with age, serum total calcium (p=.004, r=.328), creatinine, triglycerides, and magnesium levels. A linear regression model identified calcium as a covariate with unique contribution for SUA variability. After successful parathyroidectomy, the 38 cured patients showed significantly lower serum calcium (9.3[8.7;9.75] vs. 11.55[11;12.12], p .001) and SUA (4.95[3.52;6.3] vs. 5.65[4.49;7.45], p=.011) levels compared to baseline. Conclusions: Hyperuricemic PHPT patients have significantly higher levels of serum calcium, which is also an independent determinant of SUA variability. Patients who undergo successful parathyroidectomies show a significant decrease in SUA during 1 year of follow-up.

Disparities in Time to Surgeon Evaluation Among Patients with Primary Hyperparathyroidism.

BACKGROUND: A majority of patients with primary hyperparathyroidism are not referred for surgical evaluation. We hypothesized that disparities in the rate of surgeon evaluation by language, race and ethnicity, and insurance contribute to this deficit. METHODS: We queried our institutional electronic health record registry for patients with first-incident hypercalcemia between 2010 and 2018 and subsequent biochemical diagnosis of primary hyperparathyroidism. We used the Kaplan-Meier method and Cox proportional hazards modeling to investigate estimated time to surgeon evaluation by language, race and ethnicity, and insurance status. RESULTS: Of 1,333 patients with a diagnosis of primary hyperparathyroidism, 74% were female, 67% were White, 44% were privately insured, and 88% preferred English. Fewer than one third (n = 377; 28%) were evaluated by a surgeon. After adjusting for demographic and clinical factors, Asian (hazard ratio = 0.38; 95% confidence interval, 0.18-0.84; P = .016) and Black or African American patients (hazard ratio = 0.59; 95% confidence interval, 0.39-0.90; P = .014) had a lower rate of surgeon evaluation compared to White patients. Although patients with Medicaid had a lower rate of surgeon evaluation compared to privately insured patients (hazard ratio = 0.52; 95% confidence interval, 0.35-0.77; P = .001), there was no difference in rate for those with Medicare or who were uninsured. Patients with non-English and non-Spanish language had a lower rate of evaluation compared to those who preferred English (hazard ratio = 0.47; 95% confidence interval, 0.23-0.98; P = .043). CONCLUSION: Rates of surgeon evaluation vary by race and ethnicity, insurance status, and preferred language. Evaluation of factors contributing to these disparities is needed to improve access to surgeon referral.

A cost-utility analysis of 18F-fluorocholine-positron emission tomography imaging for localizing primary hyperparathyroidism in the United States.

BACKGROUND: Primary hyperparathyroidism historically necessitated bilateral neck exploration to remove abnormal parathyroid tissue. Improved localization allows for focused parathyroidectomy with lower complication risks. Recently, positron emission tomography using radiolabeled 18F-fluorocholine demonstrated high accuracy in detecting these lesions, but its cost-effectiveness has not been studied in the United States. METHODS: A decision tree modeled patients who underwent parathyroidectomy for primary hyperparathyroidism using single preoperative localization modalities: (1) positron emission tomography using radiolabeled 18F-fluorocholine, (2) 4-dimensional computed tomography, (3) ultrasound, and (4) sestamibi single photon emission computed tomography (SPECT). All patients underwent either focused parathyroidectomy versus bilateral neck exploration, with associated cost ($) and clinical outcomes measured in quality-adjusted life-years gained. Model parameters were informed by literature review and Medicare costs. Incremental cost-utility ratios were calculated in US dollars/quality-adjusted life-years gained, with a willingness-to-pay threshold set at $100,000/quality-adjusted life-year. One-way, 2-way, and threshold sensitivity analyses were performed. RESULTS: Positron emission tomography using radiolabeled 18F-fluorocholine gained the most quality-adjusted life-years (23.9) and was the costliest ($2,096), with a total treatment cost of $11,245 or $470/quality-adjusted life-year gained. Sestamibi single photon emission computed tomography and ultrasound were dominated strategies. Compared with 4-dimentional computed tomography, the incremental cost-utility ratio for positron emission tomography using radiolabeled 18F-fluorocholine was $91,066/quality-adjusted life-year gained in our base case analysis, which was below the willingness-to-pay threshold. In 1-way sensitivity analysis, the incremental cost-utility ratio was sensitive to test accuracy, positron emission tomography using radiolabeled 18F-fluorocholine price, postoperative complication probabilities, proportion of bilateral neck exploration patients needing overnight hospitalization, and life expectancy. CONCLUSION: Our model elucidates scenarios in which positron emission tomography using radiolabeled 18F-fluorocholine can potentially be a cost-effective imaging option for primary hyperparathyroidism in the United States. Further investigation is needed to determine the maximal cost-effectiveness for positron emission tomography using radiolabeled 18F-fluorocholine in selected populations.

[Assessment of the quality of life of patients after parathyroidectomy from standard and small access].

BACKGROUND: Primary hyperparathyroidism (PGPT) is an increase in the secretory activity of the parathyroid glands (OSH), due to their tumor or hyperplastic changes. Due to the lack of an effective alternative to the treatment of PGPT, the surgical method is still the only correct tactical solution for the management of patients with an established diagnosis of PGPT. The paper presents the long-term results and assessment of the quality of life of patients who underwent surgical treatment from standard and small access. The results obtained showed the promise of a sparing approach to the treatment of PGPT caused by LV adenoma. AIM: To study the effectiveness of surgical treatment of patients with PGPT based on the assessment of the quality of life of patients who underwent parathyroidectomy from standard and small access. MATERIALS AND METHODS: A retrospective study of the quality of life of patients with PGPT after surgical treatment was conducted using the SF-36 questionnaire and the linear analog scale (LAS). Statistical data processing is performed in the R programming language using the FMSB package. The quantitative parameters were presented as median (Median) and interquartile range (25th (1st Qu) - lower quartile and 75th (3rd Qu ) - upper quartile). As a nonparametric statistical criterion, the Mann-Whitney U-test was used, on the basis of which the p-value was calculated. The calculated data of the research results are presented in graphical form - in the form of bar charts, spider plot and barplot. RESULTS: This study involved 264 patients. The patients were divided into 2 groups: GR1 - patients operated from the Kocher access with mandatory revision of all 4 OSH, GR2 - patients who received surgical treatment from the small access with the removal of the altered OSH, without revision of the remaining OSH. When analyzing the quality of life of patients before surgery, there were no statistically significant differences in the groups in terms of PF (Physical Functioning) and VT (Vitality). Small-access parathyroidectomy (patients with GR 2) significantly improved the quality of life in the GH (General Health) and VT (Vitality) domains. The analysis of LAS before surgery between the groups showed no statistically significant differences, while after surgical treatment, the indicators on the linear analog scale differ in the direction of improvement in GR2. CONCLUSION: The results obtained in the course of the study showed the promise of a gentle approach to the treatment of PGPT caused by LV adenoma, which is reflected in higher quality of life indicators.

[Validation and testing of the Russian version of PHPQoL questionnaire for quality of life assessment in patients with primary hyperparathyroidism (PHPT)].

BACKGROUND: Quality of life (QoL) assessment before and after surgical treatment in patients with primary hyperparathyroidism (PHTP) may be useful for comprehensive evaluation of the treatment effect, as well as for monitoring of the patient' condition after surgery, including in real clinical practice. AIM: The aim of the study was to validate and test the Russian version of the PHPQoL questionnaire for assessment of the quality of life (QoL) in patients with primary hyperparathyroidism (PHPT) for further application in clinical practice and research in Russia. MATERIALS AND METHODS: The linguistic and cultural adaptation of the PHPQoL questionnaire was carried out in accordance with international guidelines. Psychometric properties of the tool, namely, its reliability, validity and sensitivity were tested in the focus group of patients with PHPTResults: In the whole, 65 patients with PHPT were involved into the study (mean age - 52.3 ± 10.5 years, 97% - -women): 67.7% patients were symptomatic, 35.4% patients had moderate or severe hypercalcemia. All the patients filled out the Russian version of PHPQoL before parathyroidectomy. One third of patients filled out the Russian version of PHPQoL twice - before surgery and 3 months after surgery. Satisfactory external and content validity of the Russian version of PHPQoL was demonstrated. Its stable structure confirmed satisfactory construct validity of the questionnaire. The ability of the tool to determine differences in severity of symptoms/problems due to PHPT before and after treatment was revealed. The positive effect of the surgery on QoL in PHPT patients was shown. CONCLUSION: The results obtained during the study confirm that the Russian version of PHPQoL is a reliable, valid and sensitive tool. Feasibility and applicability of its use in research and clinical practice in Russian endocrinology settings has been demonstrated.

Racial Disparities in Primary Hyperparathyroidism.

BACKGROUND: Racial disparities in surgery are increasingly recognized. We evaluated the impact of race on presentation, preoperative evaluation, and surgical outcomes for patients undergoing parathyroidectomy for primary hyperparathyroidism (PHPT). METHODS: We performed a retrospective cohort study of patients undergoing parathyroidectomy for PHPT at a single center (1997-2015). Patients were classified by self-identified race, as African-American or White. The primary outcome was disease severity at referral. The secondary outcome was completeness of preoperative evaluation. Operative success and surgical cure were evaluated. RESULTS: A total of 2392 patients were included. The majority of patients (87.6%) were White. African-American patients had higher rates of comorbid disease as well as higher preoperative calcium (10.9 vs.10.8 mg/dl, p < 0.001) and PTH levels (122 vs. 97 pg/ml, p < 0.001). White patients were more likely to have history of bone loss documented by DXA and nephrolithiasis. African-American patients had lower rates of complete preoperative evaluation including DXA scan. Operatively, African-American patients had larger glands by size (1.7 vs. 1.5 cm, p < 0.001) and mass (573 vs. 364 mg, p < 0.001). We observed similar operative success (98.9 vs. 98.0%, p = 0.355) and cure rates (98.3 vs. 97.0%, p = 0.756). CONCLUSIONS: At the time of surgical referral, African-American patients with PHPT have more biochemically severe disease and higher rates of incomplete evaluation. Operative success and cure rates are comparable.

Screening for primary hyperparathyroidism in a tertiary stone clinic, a useful endeavor.

INTRODUCTION AND OBJECTIVES: Primary hyperparathyroidism (1HPT) is associated with the risk of developing kidney stones. Our objective was to determine the prevalence of 1HPT amongst SF evaluated at a tertiary stone clinic and determine if it is cost-effective to screen for this condition. METHODS: We retrospectively reviewed 742 adult SF seen by a single urologic surgeon from 2012 to 2017 all of who were screened for 1HPT with an intact serum PTH (iPTH) and calcium. The diagnosis of 1HPT was based on the presence of hypercalcemia with an inappropriately elevated iPTH or a high normal serum calcium and an inappropriately elevated iPTH. The diagnosis was confirmed by surgical neck exploration. Published cost data and stone recurrence rates were utilized to create a cost-effectiveness decision tree. RESULTS OBTAINED: Fifty-three (7.1%) were diagnosed with 1HPT. 15 (28%) had hypercalcemia and inappropriately elevated iPTH, 38 (72%) had high normal serum calcium levels and inappropriately elevated iPTH. The potential diagnosis was ignored/missed by primary care physicians in 9 (17.0%) based on a review of prior lab results. Cost modeling was undertaken for 5, 10, 15, and 20-year intervals after screening. Based on our prevalence data, historical risks for recurrence and published cost data for stone treatments, cost savings in screening are realized at 10 years. CONCLUSION: These results support screening for primary hyperparathyroidism in patients evaluated in a tertiary referral setting.

Diagnostic value of four-dimensional computed tomography and four-dimensional magnetic resonance imaging in primary hyperparathyroidism when first-line imaging was inadequate.

INTRODUCTION: Accurate localisation of the abnormal hyperfunctioning gland with preoperative imaging has a critical role in parathyroid surgery to obtain a successful outcome. This study aimed to evaluate the diagnostic performance of second-line imaging and their contribution to the treatment success in primary hyperparathyroidism when the first-line methods were negative or discordant. METHODS: Among the patients who underwent parathyroidectomy due to primary hyperparathyroidism, 33 who underwent four-dimensional computed tomography and/or four-dimensional magnetic resonance imaging because of negative or discordant first-line imaging results were included. Persistent and recurrent cases were excluded. RESULTS: The majority of the patients were female (84.8%) and the mean age was 59.2 years. Seventeen patients had four-dimensional computed tomography and 25 had four-dimensional magnetic resonance imaging, respectively. Four-dimensional computed tomography and four-dimensional magnetic resonance imaging localised the culprit gland successfully in 52.9% and 84%, respectively. Twenty-five patients in whom single adenoma was detected underwent focused parathyroidectomy. The culprit gland was solitary in 32 cases and one patient had double adenoma. Normocalcaemia was achieved in all cases. Among the 29 patients who completed their postoperative sixth month success rate was 100%. CONCLUSION: Four-dimensional magnetic resonance imaging had high accuracy with fast dynamic imaging in detecting parathyroid adenomas. When the first-line imaging methods were negative or inconclusive, four-dimensional magnetic resonance imaging should be considered primarily since it is cost effective in Turkey and emits no radiation.

Derivation of a cost-saving screening strategy for asymptomatic primary hyperparathyroidism.

BACKGROUND: Our study seeks to find a cost-saving screening strategy in a primary care population for diagnosing primary hyperparathyroidism based on peak serum total calcium level, age, and patient sex. METHODS: Laboratory data resulting from primary care office visits at our institution between January 2016 through December 2017 to evaluate patients who had at least 1 episode of hypercalcemia (≥10.5 mg/dL). For each serum calcium threshold, we calculated the percentage of patients who were found to have an increased parathyroid hormone level (≥65 pg/mL). We determined whether net cost savings could be achieved by screening hypercalcemic patients given their probability of primary hyperparathyroidism and expected cost savings from fracture risk reduction, given their sex and age. RESULTS: From 155,350 unique patients in the study period, a total of 2,271 had a minimum of 1 hypercalcemic lab value. After exclusion criteria, there were 1,326 patients of whom 27.5% had a parathyroid hormone level checked. Cost savings was established at a screening threshold of 10.5 for all patients until age 66 years for men and 69 years for women. For men aged 67-68 y and women aged 70-71 years, the optimal screening threshold was 10.8 mg/dl. CONCLUSION: Cost savings can be achieved by screening hypercalcemic patients with a life expectancy exceeding 16 years, with varying thresholds based on age and sex.

Parathyroidectomy for asymptomatic primary hyperparathyroidism: A revised cost-effectiveness analysis incorporating fracture risk reduction.

BACKGROUND: Recent data demonstrate decreased fracture risk after operation for asymptomatic primary hyperparathyroidism. We performed a revised cost-effectiveness analysis comparing parathyroidectomy versus observation while incorporating fracture risk reduction. METHODS: A Markov transition-state model was created comparing parathyroidectomy and guideline-based medical observation for a 60-year-old female patient with mild asymptomatic primary hyperparathyroidism. Costs were estimated using published Medicare reimbursement data. Treatment strategy outcomes, including risk of fracture, were identified by literature review. Quality adjustment factors were used to weight treatment outcomes. A threshold of $100,000/quality-adjusted life year was used to determine cost-effectiveness. Sensitivity analyses and Monte Carlo simulation were performed to examine the effect of uncertainty on the model. RESULTS: Parathyroidectomy was the dominant strategy (less costly and more effective) with an incremental cost savings of $1,721 and an incremental effectiveness of 0.185 quality-adjusted life years. Parathyroidectomy remained dominant when the relative risk reduction of fracture after operation was ≥14%, the cost of fracture was ≥$7,600, or the probability of recurrent laryngeal nerve injury was <12.5%. Monte Carlo simulation showed parathyroidectomy was cost-effective in 995/1,000 hypothetical patients. CONCLUSION: When fracture risk reduction is considered, parathyroidectomy for mild asymptomatic primary hyperparathyroidism is the dominant strategy when compared to observation.

Laboratory approaches for the diagnosis and assessment of hypercalcemia.

Calcium, the fifth most common element in the body, plays major physiological functions. Measurement of blood calcium is one of the most commonly ordered laboratory tests in assessments of calcium homeostasis and disease diagnosis. Hypercalcemia is an increased level of calcium in the blood. This disorder is most commonly caused by primary hyperparathyroidism and malignancy. However, other less common causes of elevated calcium levels need to be considered when making a differential diagnosis. This review is intended to provide readers with a better understanding of calcium homeostasis and the causes and pathophysiology of hypercalcemia. Most importantly, this review describes useful approaches for laboratory scientists and clinicians to appropriately diagnose and assess hypercalcemia.

Assessment of mean platelet volume (MPV) in primary hyperparathyroidism: effects of successful parathyroidectomy on MPV levels.

OBJECTIVE: A determinant of platelet function - mean platelet volume (MPV), is newly emerging risk factor for atherothrombosis. The aim of this study is to evaluate MPV in patients with primary hyperparathyroidism (PHPT) before parathyroidectomy (PTX) and six months after successful PTX in a retrospective study. METHODS: We analyzed the changes in serum biochemical, parathyroid hormone (PTH) and MPV before and six months after PTX in 66 patients with PHPT and 44 healthy controls, age- and sex-matched. RESULTS: Sixty-six patients (18 men, 48 women) with mean age 53.8 ± 12.7 years were analyzed. MPV was significantly higher in the patients with PHPT before PTX than in the same group after PTX (9.26 ± 1.20 fl vs. 7.99 ± 0.80 fl, p<0.0001). MPV levels were positively correlated with PTH (r=0.888, p<0.0001), calcium (r=0.292, p=0.017) in the preoperative phase. Postoperative (after 6 months) MPV showed a significant positive correlation with postoperative PTH (r=0.381, p=0.002) and calcium levels (r=0.324, p=0.008). CONCLUSIONS: These results suggest that subjects with PHPT lead to have increased platelet activation.

Minimizing cost and maximizing success in the preoperative localization strategy for primary hyperparathyroidism.

Ultrasonography of the thyroid, parathyroid, and soft tissues of the neck should always be performed before parathyroidectomy. The most cost-effective localization strategies seem to be ultrasonography followed by four-dimensional computed tomography (4DCT) or ultrasonography followed by sestamibi ± 4DCT. These localization strategies are highly dependent on the quality of imaging. Surgeons should critically evaluate the imaging and operative data at their own institution to determine the best preoperative localization strategy before parathyroidectomy. Surgeons should communicate with the referring physicians about the best localization algorithms in the local area and become the decision maker as to when to obtain them.

Preoperative localization strategies for primary hyperparathyroidism: an economic analysis.

BACKGROUND: Strategies for localizing parathyroid pathology preoperatively vary in cost and accuracy. Our purpose was to compute and compare comprehensive costs associated with common localization strategies. METHODS: A decision-analytic model was developed to evaluate comprehensive, short-term costs of parathyroid localization strategies for patients with primary hyperparathyroidism. Eight strategies were compared. Probabilities of accurate localization were extracted from the literature, and costs associated with each strategy were based on 2011 Medicare reimbursement schedules. Differential cost considerations included outpatient versus inpatient surgeries, operative time, and costs of imaging. Sensitivity analyses were performed to determine effects of variability in key model parameters upon model results. RESULTS: Ultrasound (US) followed by 4D-CT was the least expensive strategy ($5,901), followed by US alone ($6,028), and 4D-CT alone ($6,110). Strategies including sestamibi (SM) were more expensive, with associated expenditures of up to $6,329 for contemporaneous US and SM. Four-gland, bilateral neck exploration (BNE) was the most expensive strategy ($6,824). Differences in cost were dependent upon differences in the sensitivity of each strategy for detecting single-gland disease, which determined the proportion of patients able to undergo outpatient minimally invasive parathyroidectomy. In sensitivity analysis, US alone was preferred over US followed by 4D-CT only when both the sensitivity of US alone for detecting an adenoma was ≥ 94 %, and the sensitivity of 4D-CT following negative US was ≤ 39 %. 4D-CT alone was the least costly strategy when US sensitivity was ≤ 31 %. CONCLUSIONS: Among commonly used strategies for preoperative localization of parathyroid pathology, US followed by selective 4D-CT is the least expensive.

Would scan, but which scan? A cost-utility analysis to optimize preoperative imaging for primary hyperparathyroidism.

BACKGROUND: Minimally invasive parathyroidectomy for primary hyperparathyroidism depends on accurate preoperative localization. This study examines the cost-utility of sestamibi in combination with single photon emission computed tomography (sestamibi-SPECT); ultrasound; and 4-dimensional computed tomography (4D-CT). METHODS: A decision tree was constructed for patients undergoing initial parathyroidectomy. Patients were randomized to 1 of 5 preoperative localization protocols: (1) ultrasound; (2) sestamibi-SPECT; (3) 4D-CT; (4) sestamibi-SPECT and ultrasound; and (5) sestamibi-SPECT and ultrasound and 4D-CT, if discordant (sestamibi-SPECT and ultrasound ± 4D-CT). From a societal perspective, all relevant costs were included. Input data were obtained from literature and Medicare. The incremental cost-utility ratio was determined in dollars per quality-adjusted life years ($/QALY). Sensitivity analyses were performed. RESULTS: In the base-case, ultrasound was least expensive, with a cost of $6666, compared to $6773 (4-D CT); $7214 (sestamibi-SPECT and ultrasound ± 4D-CT); $7330 (sestamibi-SPECT); and $7371(sestamibi-SPECT and ultrasound). Sestamibi-SPECT and ultrasound ± 4D-CT were most cost-effective because improved localization resulted in fewer bilateral explorations. QALY were comparable across modalities. Compared to sestamibi-SPECT, ultrasound, 4D- CT, and sestamibi-SPECT and ultrasound ± 4D-CT resulted a win-win situation-costing less and accruing more utility. Sensitivity analyses demonstrated that the model was sensitive to surgery cost and diagnostic accuracy of imaging. CONCLUSION: In our model, sestamibi-SPECT and ultrasound ± 4D-CT were the most cost-effective methods, followed by 4D-CT and ultrasound. Sestamibi-SPECT alone was least cost-effective. Cost-utilities were dependent on the sensitivities of ultrasound and 4D-CT and may vary by institution.

Telemedicine--an efficient and cost-effective approach in parathyroid surgery.

OBJECTIVES/HYPOTHESIS: To demonstrate the effectiveness and cost benefit of using telemedicine for the postoperative visit in patients undergoing parathyroidectomy for primary hyperparathyroidism. STUDY DESIGN: Prospective noncontrolled study at a tertiary medical center of a cohort of 39 patients undergoing postoperative care after parathyroidectomy through TeleHealth at a number of sites at various distances from the primary surgical facility. METHODS: From October 2006 through January 2010, 149 patients underwent parathyroidectomy for primary hyperparathyroidism at one tertiary medical center by a single surgeon. Age, sex, distance from the patient's home to the surgical center and to the TeleHealth site, effective completion of the TeleHealth visit, and postoperative complications were recorded. RESULTS: Of the 149 patients who underwent parathyroidectomy, 39 had their postoperative visit using TeleHealth (26%). There were 26 females (67%) and 13 (33%) males. Mean age was 64 years. All visits were effectively carried out and completed with a nurse and the patient at a remote TeleHealth site and the surgeon at the surgical center site. There were no postoperative surgical complications noted with the visits. Average round-distance travel saved was 119 miles. The travel distance saved translated into an average savings of $357.00 per patient (which included estimations of transportation costs and lost work time), with further immeasurable benefits to the patient and healthcare system. CONCLUSIONS: TeleHealth is a cost-effective and efficient way to follow-up with patients who have undergone parathyroidectomy, with significant convenience and financial benefits for the patient and healthcare system.

Variation in plasma calcium analysis in primary care in Sweden--a multilevel analysis.

BACKGROUND: Primary hyperparathyroidism (pHPT) is a common disease that often remains undetected and causes severe disturbance especially in postmenopausal women. Therefore, national recommendations promoting early pHPT detection by plasma calcium (P-Ca) have been issued in Sweden. In this study we aimed to investigate variation of P-Ca analysis between physicians and health care centres (HCCs) in primary care in county of Skaraborg, Sweden. METHODS: In this cross sectional study of patients' records during 2005 we analysed records from 154 629 patients attending 457 physicians at 24 HCCs. We used multilevel logistic regression analysis (MLRA) and adjusted for patient, physician and HCC characteristics. Differences were expressed as median odds ratio (MOR). RESULTS: There was a substantial variation in number of P-Ca analyses between both HCCs (MORHCC 1.65 [1.44-2.07]) and physicians (MORphysician 1.95 [1.85-2.08]). The odds for a P-Ca analysis were lower for male patients (OR 0.80 [0.77-0.83]) and increased with the number of diagnoses (OR 25.8 [23.5-28.5]). Sex of the physician had no influence on P-Ca test ordering (OR 0.93 [0.78-1.09]). Physicians under education ordered most P-Ca analyses (OR 1.69 [1.35-2.24]) and locum least (OR 0.73 [0.57-0.94]). More of the variance was attributed to the physician level than the HCC level. Different mix of patients did not explain this variance between physicians. Theoretically, if a patient were able to change both GP and HCC, the odds of a P-Ca analysis would in median increase by 2.45. Including characteristics of the patients, physicians and HCCs in the MLRA model did not explain the variance. CONCLUSIONS: The physician level was more important than the HCC level for the variation in P-Ca analysis, but further exploration of unidentified contextual factors is crucial for future monitoring of practice variation.

Avaliação da hipercalcemia assintomática em pacientes ambulatoriais / Assessment of asymptomatic hypercalcemia in outpatients

Introdução: Dosagens indiscriminadas de cálcio sérico podem levar à detecção de pacientes assintomáticos, com hipercalcemia, em que o hiperparatireoidismo primário é a causa mais comum. Objetivo: Discutir aforma de avaliação da hipercalcemia detectada em população atendida em regime ambulatorial, avaliando a sua freqüência, com ênfase na pesquisa de hiperparatireoidismo primário. Material e métodos: Foi realizado estudo prospectivo envolvendo 1.049 indivíduos, de 40 a 60 anos, com dosagens séricas de cálcio e albumina, e calculado o valor de cálcio corrigido. Na presença de elevação do cálcio corrigido,foram dosados cálcio iônico, fósforo, paratormônio (PTH) e calciúria. Resultados: A idade foi 49,7 ± 13,7anos e 188 (17,9%) indivíduos apresentaram valores elevados de cálcio corrigido. Desses, 90 pacientescompareceram à segunda avaliação e 19 (2%) mantiveram quadro de hipercalcemia. Os níveis de cálcio iônico (média: 1,2 ± 0,01 mmol/l) foram normais em todos os indivíduos. A calciúria foi 185,8 ± 111,8 mg/24 horas. Os níveis de PTH (média: 46 ± 11,8 pg/ml) foram elevados em três casos, com cintilografia de paratireóides normal. Discussão: A queda na freqüência de hipercalcemia com base novalor do cálcio corrigido e, sobretudo, após dosagem de cálcio ionizável sugere que a dosagem de cálcio livre seja preferida como triagem. Na população estudada não foi diagnosticado hiperparatireoidismo, sugerindo distribuição variável da doença em diferentes populações. Conclusão: Deve ser questionada a dosagem rotineira de cálcio sérico em indivíduos sem quadro clínico que indique a necessidade darealização desse exame. Quando realizada, a dosagem de cálcio iônico deverá ser preferida.

Introduction: Indiscriminate serum calcium measurement may lead to the identification of asymptomatic patientswith hypercalcaemia, which is caused mostly by primary hyperparathyroidism. Objective: To discuss the frequencyof hypercalcaemia and the type of assessment of this condition in an outpatient population, with emphasis on the investigation of primary hyperparathyroidism. Material and methods: In a prospective study 1,049 subjects (age range: 40 to 60 years old) underwent serum calcium and albumin determination and the corrected calcium values were calculated. When there was a rise in the corrected calcium level, ionized calcium, phosphate, parathyroid hormone (PTH) and urinary calcium were measured. Results: The average age was 49.7 ± 13.7 years old, and 188 subjects (17.9%) had elevated corrected calcium levels. Among these, 90 patients underwent the second investigation and 19 (2%) remained hypercalcemic. Ionized calcium levels (average: 1.2 ± 0.01 mmol/L) werenormal in all subjects. Urinary calcium was 185.8 ± 111.8 mg/24 hours. PTH levels (average: 46 ± 11.8 pg/mL)were elevated in three subjects whose parathyroid scintigraphies were normal. Discussion: The fall in the frequencyof hypercalcaemia based on corrected serum calcium levels and mostly after determination of serum ionized calciumsuggests that determinations of serum free calcium are a better screening test. No subject was diagnosed with hyperparathyroidism, what suggests an uneven distribution of the disease in different populations. Conclusion:Routine serum calcium determinations in asymptomatic patients must be questioned. When serum calcium determination is thought necessary, ionized calcium levels should be favored.