Rescoring the NIH chronic prostatitis symptom index: nothing new.

The National Institutes of Health-chronic prostatitis symptom index (NIH-CPSI) is a commonly used 13-item questionnaire for the assessment of symptom severity in men with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). For each item, score ranges are 0-1 (6 items), 0-3 (2 items), 0-5 (3 items), 0-6 (1 item) and 0-10 (1 item). This scoring system is straightforward, but items with wider score ranges are de facto weighted more, which could adversely affect the performance characteristics of the questionnaire. We rescored the NIH-CPSI so that equal weights were assigned to each item, and compared the performance of the standard and rescored questionnaires using the original validation dataset. Both the original and revised versions of the scoring algorithm discriminated similarly among groups of men with CP (n=151), benign prostatic hyperplasia (n=149) and controls (n=134). The internal consistency of the questionnaire was slightly better with the revised scoring, but values with the standard scoring were sufficiently high (Cronbach's >or=0.80). We conclude that although the rescored NIH-CPSI provides better face validity than the standard scoring algorithm, it requires additional calculation efforts and yields only marginal improvements in performance.

Primary care physician practices in the diagnosis, treatment and management of men with chronic prostatitis/chronic pelvic pain syndrome.

To describe practice patterns of primary care physicians (PCPs) for the diagnosis, treatment and management of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), we surveyed 556 PCPs in Boston, Chicago, and Los Angeles (RR=52%). Only 62% reported ever seeing a patient like the one described in the vignette. In all, 16% were 'not at all' familiar with CP/CPPS, and 48% were 'not at all' familiar with the National Institutes of Health classification scheme. PCPs reported practice patterns regarding CP/CPPS, which are not supported by evidence. Although studies suggest that CP/CPPS is common, many PCPs reported little or no familiarity, important knowledge deficits and limited experience in managing men with this syndrome.

Responsiveness of the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI).

OBJECTIVES: The NIH-Chronic Prostatitis Symptom Index (NIH-CPSI) was developed to assess symptoms and quality of life in men with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). We assessed the responsiveness of the NIH-CPSI to change over time and defined thresholds for changes perceptible to patients. METHODS: We studied 174 men with CP/CPPS who participated in a placebo-controlled randomized clinical trial. Changes from baseline to six weeks in the NIH-CPSI total score and pain, urinary, and quality of life subscores were compared to a global response assessment (GRA). Effect sizes and Guyatt statistics were calculated to evaluate responsiveness; 95% confidence intervals were produced using bootstrapping. RESULTS: All scores decreased over time with the largest decrease in subjects who reported on the GRA that they were markedly improved. The NIH-CPSI total, pain, and quality of life scores were highly responsive in the improved groups; the urinary score showed minimal responsiveness. There was no evidence of responsiveness among those subjects who worsened on the trial. ROC curves identified a 6-point decline in the NIH-CPSI total score as the optimal threshold to predict treatment response. CONCLUSIONS: The NIH-CPSI total score and pain and quality of life subscores are responsive to change over time.

Does fetal fibronectin use in the diagnosis of preterm labor affect physician behavior and health care costs? A randomized trial.

OBJECTIVE: The purpose of this study was to determine whether a knowledge of fetal fibronectin results affects patient treatment and health care costs. STUDY DESIGN: Women between 24 and 34 weeks of gestation with a singleton pregnancy and preterm uterine contractions were eligible for enrollment. Once informed consent was given, a fetal fibronectin specimen was obtained, and women were assigned randomly into 2 groups. In 1 group, results of the fetal fibronectin test were available; in the other group, results were not available. The use of inpatient and outpatient health care resources subsequent to enrollment was ascertained through the use of medical records, hospital billing data, and patient interviews. This study was powered to allow the detection in the fetal fibronectin group of a 20% reduction in total health care-related costs. RESULTS: The 2 groups were similar with respect to maternal age, parity, race, cervical examination at admission, and estimated gestational age at enrollment and at delivery. Women who did not have fetal fibronectin results available were no different than those women who did with respect to initial length of labor and delivery observation (median, 4 hours vs 3 hours), hospital admission (28% vs 26%), tocolysis (18% vs 16%), cessation of work (27% vs 26%), or total health care-related costs (log mean +/- SD, 7.6 +/- 1.2 vs 7.5 +/- 1.1). CONCLUSION: In this study population, the use of fetal fibronectin did not affect physician behavior or health care costs related to preterm contractions.

Psychometric evaluation of the Functional Assessment of Cancer Therapy/Gynecologic Oncology Group-Neurotoxicity (Fact/GOG-Ntx) questionnaire for patients receiving systemic chemotherapy.

The purpose of this study was to validate the Functional Assessment of Cancer Therapy/Gynecologic Oncology Group-Neurotoxicity (FACT/GOG-Ntx) questionnaire. The FACT/GOG-Ntx is the FACT-G plus an eleven-item subscale (Ntx subscale) that evaluates symptoms and concerns associated specifically with chemotherapy-induced neuropathy. Two groups of women with ovarian cancer completed the FACT/GOG-Ntx: one group with known neurotoxicities and one group of chemotherapy-naive women newly diagnosed with ovarian cancer. Levels of patient neuropathy, severity of toxicity, and patient quality of life from diagnosis of ovarian cancer to 12 months post-diagnosis were assessed. The Ntx subscale significantly differentiated the two groups at baseline and 3- and 6-month follow-ups, demonstrating significantly fewer problems among chemotherapy-naive patients than among patients with known neuropathy. The FACT/GOG-Ntx is a reliable and valid instrument for assessing the impact of neuropathy on health-related quality of life. The Ntx subscale demonstrated sensitivity to meaningful clinical distinctions and change over time.

Preference assessment of prenatal diagnosis for Down syndrome: is 35 years a rational cutoff?

OBJECTIVE: To compare the perceptions of miscarriage and birth of a child with Down syndrome among pregnant women and to evaluate the implications of these preferences for the traditional 35-year old maternal age risk boundary. METHODS: An interviewer-administered survey was given to 186 pregnant women receiving antepartum care at a university hospital. Preferences, as reflected by utilities, for birth of a child with Down syndrome and pregnancy miscarriage, stratified by patient characteristics, were assessed. RESULTS: The utility for the birth of a child with Down syndrome decreased (p < 0.001) as clinical severity increased from mild (0.78) to severe (0.65). Miscarriage of a pregnancy had a mean utility of 0.76 +/- 0.31. Women who desired prenatal diagnosis had a utility value for miscarriage (0.79 +/- 0.28) that was significantly higher than for the birth of a child with Down syndrome of unknown severity (0.73 +/- 0.27). In multivariable logistic regression, desire for prenatal diagnosis was the only factor associated with a preference of miscarriage over birth of an affected child (odds ratio 2.26, 95% confidence interval 1.03, 4.96). CONCLUSION: Women who desire prenatal diagnosis do not perceive the birth of a child with Down syndrome and a pregnancy miscarriage to be equivalent health states. This finding calls into question the rationale of the 35-year-old maternal age criterion and suggests that actual patient preferences should be better incorporated into the decision to offer definitive prenatal diagnosis.

The Spanish National Institutes of Health-Chronic Prostatitis Symptom Index: translation and linguistic validation.

PURPOSE: The prominence of health related quality of life end points in international clinical research underscores the importance of well validated and translated measures to enable cross-cultural comparison. The National Institutes of Health (NIH)-Chronic Prostatitis Symptom Index (CPSI) assesses symptoms and health related quality of life in men with chronic nonbacterial, NIH type III prostatitis. To expand its use to Spanish speaking patients we performed a translation and linguistic validation. MATERIALS AND METHODS: The 9-item NIH-CPSI was translated into Spanish according to a standard methodology of 2 forward translations, 1 reconciled version, back translation of the reconciled version and 3 independent reviews by bilingual experts. The purpose of this methodology was to create a single universal Spanish version that would be acceptable to native Spanish speakers inside and outside of the United States. After the translation process the Spanish version was pre-tested in Argentina, Mexico, Spain and the United States. Patient responses were analyzed to identify necessary modifications. The internal consistency of the CPSI was evaluated using Cronbach's alpha. Pearson's product moment correlations were used to evaluate construct validity. RESULTS: Data were collected from chronic prostatitis patients, including 15 in Argentina, 15 in Mexico, 4 in the United States and 3 in Spain. The translation had high reliability overall and in all subscales (Cronbach's coefficient alpha = 0.81 to 0.94), and the subscales correlated well with each other (r = 0.76 to 0.97). However, patients expressed difficulty in distinguishing the response categories "a menudo" ("often") from "normalmente" ("usually") in question 3. We revised "a menudo" to "muchas veces" ("much of the time") and "normalmente" to "casi siempre" ("almost always") to improve the distinctiveness of response categories. CONCLUSIONS: The Spanish NIH-CPSI has high reliability as well as face and construct validity in Spanish speaking men from various countries. The Spanish NIH-CPSI permits cross-cultural comparisons of men with chronic nonbacterial prostatitis.

Quality of life is impaired in men with chronic prostatitis: the Chronic Prostatitis Collaborative Research Network.

OBJECTIVE: Health-related quality of life (HRQOL) impairment may be a central component of chronic prostatitis for men afflicted with this condition. Our objective was to examine HRQOL, and factors associated with HRQOL, using both general and condition-specific instruments. DESIGN: Chronic Prostatitis Cohort (CPC) study. SETTING: Six clinical research centers across the United States and Canada. PARTICIPANTS: Two hundred seventy-eight men with chronic prostatitis. MEASUREMENTS AND MAIN RESULTS: The Short Form 12 (SF-12) Mental Component Summary (MCS) and Physical Component Summary (PCS), and the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) were measures used. CPC subjects' MCS scores (44.0 +/- 9.8) were lower than those observed in the most severe subgroups of patients with congestive heart failure and diabetes mellitus, and PCS scores (46.4+/-9.5) were worse than those among the general U.S. male population. Decreasing scores were seen in both domains with worsening symptom severity (P < .01). History of psychiatric disease and younger age were strongly associated with worse MCS scores, whereas history of rheumatologic disease was associated with worse PCS scores. Predictors of more severe NIH-CPSI scores included lower educational level and lower income; history of rheumatic disease was associated with higher scores. CONCLUSIONS: Men with chronic prostatitis experience impairment in the mental and physical domains of general HRQOL, as well as condition-specific HRQOL. To optimize the care of men with this condition, clinicians should consider administering HRQOL instruments to their patients to better understand the impact of the condition on patients' lives.

Evaluating the total costs of chemotherapy-induced toxicity: results from a pilot study with ovarian cancer patients.

PURPOSE: While chemotherapy-related toxicities affect cancer patients' activities of daily living and result in large expenditures of medical care for treatment, few studies have assessed the out-of-pocket and indirect costs incurred by patients who experience toxicity. The objective of this study was to evaluate the feasibility of obtaining detailed and comprehensive cost information from patients who experienced neutropenia, thrombocytopenia, or neurotoxicity during treatment. METHODS: Ovarian cancer patients who experienced chemotherapy-associated hematologic or neurologic toxicities were asked to record detailed information about hospitalization, laboratories, physician visits, phone calls, home visits, medication, medical devices, lost productivity, and caregivers. Resource estimates were converted into cost units, with direct medical cost estimates based on hospital cost-accounting data and indirect costs (i.e., productivity loss) on modified labor force, employment, and earnings data. RESULTS: Direct medical costs were highest for neutropenia (mean of $7,546/episode), intermediate for thrombocytopenia (mean of $3,268/episode), and lowest for neurotoxicity (mean of $688/episode). Indirect costs relating to patient and caregiver work loss and payments for caregiver support were substantial, accounting for $4,220, $3,834, and $4,282 for patients who developed neurotoxicity, neutropenia, and thrombocytopenia, respectively. The total costs of chemotherapy-related neurotoxicity, neutropenia, and thrombocytopenia were $4,908, $11,830, and $7,550. CONCLUSION: Our study has shown that, with the assistance of patients who are experiencing toxicity, estimation of the total costs of cancer-related toxicities is feasible. Indirect costs, while not included in prior estimates of the costs of toxicity studies, accounted for 34% to 86% of the total costs of cancer supportive care.

Purification and characterization of cholesterol sulfotransferase from rat skin.

Previous work has demonstrated that the activity of the enzyme cholesterol sulfotransferase is rapidly and dramatically increased upon squamous differentiation of a variety of epithelial cells in culture, including epidermal keratinocytes. As a step toward understanding the molecular mechanisms underlying this differentiation-related change, we now report the partial purification and characterization of this enzyme activity from rat skin. Supernatant solutions from rat skin homogenates were subjected to a series of column chromatography steps including anion exchange, gel filtration, chromatofocusing and hydrophobic interaction chromatography. The purification procedure resulted in cholesterol sulfotransferase activity purified 2,700-fold with a 11% recovery. The most purified preparation yielded a major Coomassie blue-stained band on denaturing polyacrylamide gel electrophoresis of an apparent molecular weight (MW) of 40,000 Da. Photoaffinity labeling with the donor substrate, 3'-phosphoadenosine-5'-phospho-[35S]-sulfate resulted in a single radiolabeled protein band on denaturing polyacrylamide gel electrophoresis, again of apparent MW 40,000 Da, strongly suggesting that the major Coomassie blue-stained band in the most purified preparation is the cholesterol sulfotransferase protein. Among 3beta-hydroxysteroids with a A5 double bond that were tested, each served as a substrate, while androgens, estrogens, corticosteroids, p-nitrophenol and DOPA did not serve as substrates. Apparent Michaelis constants for the 3beta-hydroxysteroid substrates ranged from 0.6 to 8 microM.

Genetic analysis of early- versus late-stage ovarian tumors.

In the United States, ovarian cancer is the fourth most common cause of cancer-related deaths among women. The most important prognostic factor for this cancer is tumor stage, or extent of disease at diagnosis. Although women with low-stage tumors have a relatively good prognosis, most women diagnosed with late-stage disease eventually succumb to their cancer. In an attempt to understand early events in ovarian carcinogenesis, and to explore steps in its progression, we have applied multiple molecular genetic techniques to the analysis of 21 early-stage (stage I/II) and 17 advanced-stage (stage III/IV) ovarian tumors. These techniques included expression profiling with cDNA microarrays containing approximately 18,000 expressed sequences, and comparative genomic hybridization to address the chromosomal locations of copy number gains as well as losses. Results from the analysis indicate that early-stage ovarian cancers exhibit profound alterations in gene expression, many of which are similar to those identified in late-stage tumors. However, differences observed at the genomic level suggest differences between the early- and late-stage tumors and provide support for a progression model for ovarian cancer development.

IL-1beta and TNF-alpha in prostatic secretions are indicators in the evaluation of men with chronic prostatitis.

PURPOSE: Chronic Prostatitis, or Chronic Pelvic Pain Syndrome [CPPS], is a common disorder characterized by pelvic pain and varying degrees of inflammation in expressed prostatic secretions (EPS). In search of markers to more clearly define CPPS, we compared proinflammatory cytokines interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) levels in EPS from men with CPPS, to healthy men and men with Benign Prostatic Hyperplasia (BPH). METHODS: 78 men: controls (n = 16), BPH (n = 14), CPPS IIIA [>/=10 white blood cells per high power field (WBC/hpf) in EPS] (n = 18), CPPS IIIB [<10 WBC/hpf in EPS] (n = 20), and asymptomatic inflammatory prostatitis (AIP) (n = 10) were evaluated for EPS WBC, and IL-1beta and TNF-alpha by ELISA. RESULTS: IL-1beta and TNF-alpha levels in EPS were usually detectable in men with CPPS IIIA (89% and 45%, respectively) or AIP (90%; 100%), but less often in controls (31%; 17%), BPH (57%; 15%), and CPPS IIIB (35%; 15%) respectively. IL-1beta and TNF-alpha levels were higher in CPPS IIIA versus CPPS IIIB, and in AIP versus controls or BPH (p's <0.001). Cut-points for IL-1beta and TNF-alpha discriminated AIP from controls (predictive values = 94% and 83%, respectively) and CPPS IIIA from CPPS IIIB (predictive values 84% and 100%). Overall, there was a correlation between IL-1beta and TNF-alpha (p <0.003), but no correlation between WBC and IL-1beta (p <0.1) or TNF-alpha (p <0.50). CONCLUSIONS: Cytokines are frequently present and elevated in the EPS from men with CPPS IIIA and AIP and provide a novel means for identification, characterization and potential management of men with CPPS that differs from traditional methods based on WBC.

Cost analysis of second-line therapies for platinum-refractory ovarian cancer: reimbursement dilemmas for Medicare patients.

Currently used options for salvage therapy for epithelial ovarian cancer include intravenously administered paclitaxel or topotecan and orally administered altretamine or etoposide. The response rates for these agents are similar (14-26%), whereas the type and incidence of adverse events differ. Under current legislation, Medicare will reimburse intravenous outpatient chemotherapy regimens only or oral regimens with a marketed intravenous formulation, despite that 89% of cancer patients prefer oral therapies. To compare the out-of-pocket costs and costs to the Medicare system, a cost minimization analysis of treatment with these agents was conducted using published phase II and phase III data. The total cost of treatment was $15,767 for paclitaxel, $18,635 for topotecan, $4477 for altretamine, and $5016 for etoposide. The out-of-pocket costs to the patient were $83, $37, $4477, and $6, respectively. Although a physician's first consideration in choosing a therapy is efficacy and toxicity, current Medicare reimbursement policies restrict patient options for cancer care. Because Medicare adopts managed care and health maintenance organizations into the management of patient care, cost effectiveness will likely become an important consideration in the treatment of cancer.

The National Institutes of Health chronic prostatitis symptom index: development and validation of a new outcome measure. Chronic Prostatitis Collaborative Research Network.

PURPOSE: Chronic abacterial prostatitis is a syndrome characterized by pelvic pain and voiding symptoms, which is poorly defined, poorly understood, poorly treated and bothersome. Research and clinical efforts to help men with this syndrome have been hampered by the absence of a widely accepted, reliable and valid instrument to measure symptoms and quality of life impact. We developed a psychometrically valid index of symptoms and quality of life impact for men with chronic prostatitis. MATERIALS AND METHODS: We conducted a structured literature review of previous work to provide a foundation for the new instrument. We then conducted a series of focus groups comprising chronic prostatitis patients at 4 centers in North America, in which we identified the most important symptoms and effects of the condition. The results were used to create an initial draft of 55 questions that were used for formal cognitive testing on chronic prostatitis patients at the same centers. After expert panel review formal validation testing of a revised 21-item draft was performed in a diverse group of chronic prostatitis patients and 2 control groups of benign prostatic hyperplasia patients and healthy men. Based on this validation study, the index was finalized. RESULTS: Analysis yielded an index of 9 items that address 3 different aspects of the chronic prostatitis experience. The primary component was pain, which we captured in 4 items focused on location, severity and frequency. Urinary function, another important component of symptoms, was captured in 2 items (1 irritative and 1 obstructive). Quality of life impact was captured with 3 items about the effect of symptoms on daily activities. The 9 items had high test-retest reliability (r = 0.83 to 0.93) and internal consistency (alpha = 0.86 to 0.91). All but the urinary items discriminated well between men with and without chronic prostatitis. CONCLUSIONS: The National Institutes of Health chronic prostatitis symptom index provides a valid outcome measure for men with chronic prostatitis. The index is psychometrically robust, easily self-administered and highly discriminative. It was formally developed and psychometrically validated, and may be useful in clinical practice as well as research protocols.

The relation between physician experience and patterns of care for patients with AIDS-related Pneumocystis carinii pneumonia: results from a survey of 1,500 physicians in the United States.

STUDY OBJECTIVES: To determine whether physician experience and specialty influence the approach to care of AIDS patients with pneumonia, we surveyed physicians about their management of possible Pneumocystis carinii pneumonia (PCP) infection. DESIGN, SETTING, PARTICIPANTS: A postal survey was sent to a random sample of 1,500 internists and family physicians in the United States drawn from the American Medical Association master file who were identified by a pharmaceutical marketing company as having written prescriptions for AIDS-related agents in the previous year. MEASUREMENTS AND RESULTS: The survey had a 53% response rate. Physicians more experienced in AIDS care were more likely to advocate diagnostic bronchoscopy over initiation of empiric anti-PCP therapy for HIV-infected patients with undiagnosed pulmonary infiltrates (odds ratio [OR], 1.4 for a patient with mild severity of illness [p = 0.02]; OR, 1.7 for a severely ill patient [p < 0.001]). Physician specialty and fee-for-service reimbursement were independently associated with higher rates of bronchoscopy, with internists favoring bronchoscopy more frequently than family physicians. High-experience providers and internists also predicted better clinical outcomes for the hypothetical patients. CONCLUSIONS: Our findings extend the observations about HIV experience and PCP prophylaxis to the setting of diagnosis and treatment. Physicians with higher levels of experience with AIDS, internists, and physicians reimbursed as fee-for-service providers are more likely to support diagnostic confirmation of PCP than empiric treatment approaches.

Pharmacoeconomics of amifostine in ovarian cancer.

Physicians are frequently pressured to make therapeutic decisions within a cost-effective framework to demonstrate value to managed care. Because cancer is a chronic disease, health care costs are known to be expensive and physicians must use their resources as efficiently as possible. Historically, economic analyses in oncology have emphasized survival as their clinical end point. Today, both government groups and professional organizations are moving toward making quality of life the clinical end point in determining the economics of chemotherapy. This report evaluates the cost and efficacy of amifostine (Ethyol; Alza Pharmaceuticals, Palo Alto, CA/US Bioscience, West Conshohocken, PA) use in the treatment of advanced ovarian cancer using two pharmacoeconomic analyses. A cost-utility analysis performed in the United States indicated that inclusion of amifostine therapy had both a favorable clinical and cost-utility profile compared with other medical therapies. A second cost-benefit analysis, conducted in Canada, suggested that use of amifostine in patients with advanced ovarian cancer would be cost saving. Amifostine is a novel agent that protects against both chemotherapy- and radiotherapy-induced toxicities, such as nephrotoxicity, neutropenia, thrombocytopenia, peripheral neuropathy, mucositis, and xerostomia. These toxicities are disturbing to both patients and physicians alike. The results of these studies support the use of amifostine as a valuable resource both economically and clinically.

Identifying providers of care to individuals with human immunodeficiency virus for a mail survey using a prescription tracking database.

Unlike cancer and other illnesses for which specialists provide the majority of care for affected individuals, care of those infected with human immunodeficiency virus (HIV) is provided by generalists and many different types of specialists. To assess the utility of a prescription tracking database in identifying low experience and high-experience providers of such care regardless of specialty, we mailed a survey to 1500 physicians identified as having written prescriptions for agents used in care of HIV-infected individuals in the year before the survey. We discovered that physicians who care for patients with acquired immunodeficiency syndrome (AIDS) in the United States come from a broad range of specialties and practice in a variety of settings. Self-report of experience with AIDS care in the prior year was strongly associated with the number of HIV-related prescriptions identified in the tracking information. Response rates were consistent with those of other surveys published in medical journals. This study suggests that prescription tracking databases can be used to identify the breadth of physician/subjects who provide care for patients with HIV infection.

Perceptions of cisplatin-related toxicity among ovarian cancer patients and gynecologic oncologists.

BACKGROUND: We conducted a pilot study to evaluate issues related to chemotherapy-induced toxicities by eliciting assessments of toxicity from women with advanced stage ovarian cancer and gynecologic oncologists. PATIENTS AND METHODS: Fifteen ovarian cancer patients and ten gynecologic oncologists completed the survey exercises. All patients surveyed had received at least six courses of a cisplatin-containing chemotherapy regimen. RESULTS: For both patients and physicians, there was good face validity to the utility exercise as assessments of health states with cisplatin were (1) consistently associated with less favorable assessments than the health state with no toxicity and (2) neurotoxicity was viewed less favorably than either ototoxicity or nephrotoxicity. While the 15 patients as a group viewed health states with toxicity more favorably than physicians (P < 0.05 for each toxicity), patient assessments varied, depending on individual experiences with cisplatin. Physician assessments of toxicity were most similar to those obtained from patients who had not experienced cisplatin toxicity and were less favorable than those elicited from patients who had experienced any toxicity. CONCLUSIONS: In deciding upon therapeutic strategies, women with advanced stage ovarian cancer and treating physicians markedly differ in their assessment of the impact of specific toxicities on quality of life.

The influence of temporal bone anatomical variation upon the caloric stimulus.

This study involved a comparison of temperature changes occurring in isolated cadaveric temporal bones as a result of caloric stimulation, with information gained from radiological examination of the bones by means of high resolution computed tomographic scanning. This was performed in order to investigate the complex nature of heat transfer within the temporal bone and the influence which anatomical variations may have upon the accuracy of evaluation of vestibular function by means of the caloric test. No significant correlation could be found between the maximum temperature change occurring across the lateral semicircular canal and any of the parameters obtained from radiological assessment except for the diameter of the internal auditory meatus. It was deduced that an intra-subject difference in the diameters of the internal auditory meatus of 0.5 mm would introduce an absolute error in the evaluation of percentage canal paresis of 10%. Since normal intra-subject differences in internal meatus diameter can exceed 0.5 mm, this finding was considered to be highly significant.