The effect of identifying macroprolactinemia on health-care utilization and costs in patients with elevated serum prolactin levels

OBJECTIVES

The routine screening for macroprolactin of all hyperprolactinemic patients may avoid unnecessary imaging procedures and medication prescription. The study described the frequency and types of tests requested after a diagnosis of high serum prolactin concentration, and assessed whether the diagnosis of macroprolactinemia resulted in lower downstream utilization and costs compared with hyperprolactinemic patients.

METHODS

A cost analysis was conducted using a decision tree to model the health-care utilization of the two groups. The database of the Fleury Medicina e Saúde provided the tests and medication of patients with a prolactin value >or=30 microg/L for a period of 6 months.

RESULTS

Six hundred fifty-four of 1793 patients (36.5%) had hyperprolactinemia because of macroprolactin. The average number of tests per individual was higher (P = 0.001) in the patients with true hyperprolactinemia (3.07) than in patients with macroprolactinemia (2.51).The average cost in the hyperprolactinemic group (R$425 or euro 162) was significantly higher (P < 0.001) than the macroprolactinemic group (R$340 or euro 130), an incremental cost 25% higher.

CONCLUSION

The macroprolactin screening did not completely avoid inappropriate clinical investigation or associated health-care costs. Our results demonstrate the importance of proper medical education and knowledge diffusion of the meaning of macroprolactinemia.

A simple and cost-effective approach to assessment of pituitary adrenocorticotropin and growth hormone reserve: combined use of the overnight metyrapone test and insulin-like growth factor-I standard deviation scores

CONTEXT

The insulin tolerance test (ITT) is the gold standard for assessment of ACTH and GH reserve in patients with suspected hypopituitarism. It is labor intensive and costly.

OBJECTIVE

The objective of the study was to determine whether use of the overnight metyrapone test (OMT) and plasma IGF-I sd scores (SDS) could provide a cost-effective alternative to the ITT.

DESIGN

This was a retrospective chart review.

SETTING

The study was conducted at a teaching hospital.

PARTICIPANTS AND INTERVENTION

Charts from 100 patients with organic pituitary disorders were reviewed. All underwent the OMT unless 0900 h plasma cortisol was less than 80 or greater than 450 nmol/liter when ACTH deficiency or ACTH sufficiency, respectively, was diagnosed. Patients were considered GH deficient if the age-related IGF-I SDS was less than -3 or if they had three or more other pituitary hormone deficiencies. Patients were considered GH sufficient if age-related IGF-I SDS was greater than the 95th centile established from patients with known GH deficiency. Thirty-three underwent an ITT.

MAIN OUTCOME MEASURES

The proportion of patients in whom ACTH and GH reserve could be assessed using OMT/IGF-I SDS was measured. The concordance with results was obtained from ITT.

RESULTS

Fifty-five patients were ACTH sufficient and 45 were ACTH deficient. Twenty-one were GH sufficient and 33 were GH deficient based on IGF-I SDS and other pituitary hormone deficiencies, whereas 46 could not be classified. There was near-uniform concordance between OMT/IGF-I SDS and ITT. Initial investigation using OMT/IGF-I SDS resulted in a significant cost saving.

CONCLUSIONS

ACTH and GH reserve can be accurately and cost-effectively investigated using OMT/IGF-I SDS in approximately 50% of patients with organic pituitary disorders.

Short procedure of GHRH plus arginine test in clinical practice

Either in children or in adults, arginine (ARG) alone and combined with GHRH (GHRH+ARG) are reliable tests for the diagnosis of GH deficiency. The procedures of these tests generally include GH measurement every 15 min from baseline up to 90-120 min. Aim of our study was to verify if the procedure of these tests could be usefully shortened in clinical practice. To this goal we have studied 173 normally growing children and adolescents (C, 117 M and 56 F, age: 11.3 +/- 0.4 yr.) and 125 young and middle aged normal adults (A, 68 M and 57 F, age: 30.0 +/- 0.6 yr.). ARG alone test was performed by 81 C and 33 A (0.5 g/kg arginine, i.v., from 0 to +30 min, up to a maximum of 30 g) while GHRH (1 microg/kg i.v. bolus at 0 min) + ARG test was performed by 92 C and 92 A. After ARG alone, taking into account data from +15 to +105 min, GH values above the 3rd centile limit of arbitrary cut-off (7 or 10 microg/l in C and 5 microg/l in A) occurred in 85% or 64% and 94% subjects, respectively. After GHRH+ARG test, taking into account only data at +30, +45, +60 min GH values above the 3rd centile limit (20 microg/l in C and 16.5 microg/l in A) occurred in 99% of subjects in both groups. Taking into account only these 3 timing points, the percentage of GH peak above the third centile limits after ARG alone was never higher than 60% in C and 85% in A. In conclusion, this study shows that single GHRH+arginine test can be reliably performed in a shortened procedure which makes easier the clinical practice and further reduces costs.