Evaluation of ICD-10 algorithms to identify hypopituitary patients in the Danish National Patient Registry

OBJECTIVE: Routinely collected health data may be valuable sources for conducting research. This study aimed to evaluate the validity of algorithms detecting hypopituitary patients in the Danish National Patient Registry (DNPR) using medical records as reference standard. STUDY DESIGN AND SETTING: Patients with International Classification of Diseases (10th edition [ICD-10]) diagnoses of hypopituitarism, or other diagnoses of pituitary disorders assumed to be associated with an increased risk of hypopituitarism, recorded in the DNPR during 2000–2012 were identified. Medical records were reviewed to confirm or disprove hypopituitarism. RESULTS: Hypopituitarism was confirmed in 911 patients. In a candidate population of 1,661, this yielded an overall positive predictive value (PPV) of 54.8% (95% confidence interval [CI]: 52.4–57.3). Using algorithms searching for patients recorded at least one, three or five times with a diagnosis of hypopituitarism (E23.0x) and/or at least once with a diagnosis of postprocedural hypopituitarism (E89.3x), PPVs gradually increased from 73.3% (95% CI: 70.6–75.8) to 83.3% (95% CI: 80.7–85.7). Completeness for the same algorithms, however, decreased from 90.8% (95% CI: 88.7–92.6) to 82.9% (95% CI: 80.3–85.3) respectively. Including data of hormone replacement in the same algorithms PPVs increased from 73.2% (95% CI: 70.6–75.7) to 82.6% (95% CI: 80.1–84.9) and completeness decreased from 94.3% (95% CI: 92.6–95.7) to 89.7% (95% CI: 87.5–91.6) with increasing records of E23.0x. CONCLUSION: The DNPR is a valuable data source to identify hypopituitary patients using a search criteria of at least five records of E23.0x and/or at least one record of E89.3x. Completeness is increased when including hormone replacement data in the algorithm. The consequences of misclassification must, however, always be considered

The TRH test provides valuable information in the diagnosis of central hypothyroidism in patients with known pituitary disease and low T4 levels

Objective: To evaluate the value of the thyrotropin-releasing hormone (TRH) test in the diagnosis of central hypothyroidism (CH) in patients with pituitary disease. Methods: Systematic evaluation of 359 TRH tests in patients with pituitary disease including measurements of thyroxine (T4), TBG-corrected T4 (T4 corr), baseline TSH (TSH 0) and relative or absolute TSH increase (TSH fold, TSH absolute). Results: Patients diagnosed with CH (n=39) show comparable TSH 0 (p-value 0.824) but lower T4 corr (p-value &lt;0.001) and lower TSH increase (p-value &lt;0.001) compared to patients without CH. In 54% (42 of 78 cases) of patients with low T4 corr, the CH diagnosis was rejected based on a high TSH fold. In these cases, a spontaneous increase and mean normalization in T4 corr (from 62 to 73 nmol/L, p-value &lt;0.001) was observed during the follow-up period (7.6 ± 5.0 years). Three of the 42 patients (7%) were started on replacement therapy due to spontaneous deterioration of thyroid function after 2.8 years. Patients diagnosed with CH reported significantly more symptoms of hypothyroidism (p-value 0.005), although, symptoms were reported in most patients with pituitary disease. The TRH test did not provide clinical relevant information in patients with normal T4 or patients awaiting pituitary surgery (78%, 281 of 359). There were only mild and reversible adverse effects related to the TRH test except for possibly one case (0.3%) experiencing a pituitary apoplexy. Conclusion: The TRH test could be reserved to patients with pituitary disease, low T4 levels without convincing signs of CH. Approximately 50% of patients with a slightly decreased T4 were considered to have normal pituitary thyroid function based on the TRH test results.</p

Acromegaly according to the Danish National Registry of Patients:how valid are ICD diagnoses and how do patterns of registration affect the accuracy of registry data?

BACKGROUND: The incidence of acromegaly is uncertain, since population-based studies are few. In the absence of a specific acromegaly registry, the Danish National Registry of Patients (DNRP) becomes a potential source of data for studying the epidemiology of acromegaly, by linking all hospital discharge diagnoses to the personal identification numbers of individual Danish inhabitants. The validity of the DNRP with respect to acromegaly, however, remains to be tested. The aim of this study was to validate the International Classification of Diseases (ICD) codes for acromegaly (ICD-8: 25300, 25301. ICD-10: E22.0) as used in the DNRP, and to assess the influence of various registration patterns on the accuracy of registry data. METHODS: We identified patients registered with ICD codes for the diagnosis of acromegaly or other pituitary disorders during the period 1991–2009. Data on the institutional origin of each registration and the number of relevant DNRP registrations were recorded, and systematic patient chart reviews were performed to confirm the diagnosis. RESULTS: In total, 110 cases of acromegaly were confirmed, compared with 275 registered cases, yielding a positive predictive value (PPV) of 40%. When restricting the search to the regional highly specialized department of endocrinology, the PPV increased to 53% with no loss of cases with confirmed acromegaly. With a requirement of at least one, two, or three DNRP registrations, the PPV increased, but with a concurrent loss of confirmed cases. CONCLUSION: The DNRP seems to be a useful source for identifying new cases of acromegaly, especially when restricting the search to a relevant regional highly specialized department. The PPV of DNRP data used for this purpose can be increased by including only cases with several registrations. A similar approach may be successfully applied to other rare diseases in which continuity of care is provided by highly specialized departments

Carcinoid syndrome caused by a serotonin-secreting pituitary tumour

NEUROENDOCRINE TUMOURS ARE MOST FREQUENTLY LOCATED IN THE GASTROINTESTINAL ORGAN SYSTEM OR IN THE LUNGS, BUT THEY MAY OCCASIONALLY BE FOUND IN OTHER ORGANS.CASE: We describe a 56-year old woman suffering from a cardinoid syndrome caused by a large serotonin secreting pituitary tumour. She had for years suffered from episodes of palpitations, dyspnoea and flushing. Cardiac disease had been suspected, which delayed the diagnosis, until blood tests revealed elevated serotonin and chromogranin A in plasma. Somatostatin receptor (SSR) scintigraphy showed a single positive focus in the region of the pituitary gland and MRI a corresponding intra- and suprasellar heterogeneous mass. After pre-treatment with octreotide leading to symptomatic improvement, the patient underwent trans-cranial surgery with removal of the tumour. This led to clinical improvement and to a normalisation of SSR scintigraphy, as well as serotonin and chromogranin A levels