An observational study of glucocorticoid-induced osteoporosis prophylaxis in a national cohort of male veterans with rheumatoid arthritis

We applied regression techniques to a large cohort of patients to understand why certain patients are prescribed medications to prevent glucocorticoid-induced osteoporosis (GIO). Rates of prescriptions to prevent osteoporosis were low. The presence of drugs and disorders associated with osteoporosis and gastrointestinal conditions actually are associated with a decreased likelihood of receiving osteoporosis-preventing medications.

INTRODUCTION

To understand why some patients are prescribed medications to prevent GIO while other patients are not, we examined whether there is an association among osteoporosis-inducing medical conditions or medications and prescriptions for osteoporosis prophylaxis in a large cohort of rheumatoid arthritis patients on chronic glucocorticoids.

METHODS

Department of Veterans' Affairs national administrative databases were used to construct a cohort (n = 9,605) and provide the data for this study. Multivariate logistic regression was performed to determine medical conditions and medications associated with dispensing of GIO-preventive medications, controlling for sociodemographic variables, comorbidities, glucocorticoid dosage, prior fractures, and rheumatoid arthritis severity. A subanalysis examined predictors of early GIO prevention.

RESULTS

Subjects were more likely to receive GIO prophylaxis if they were older, African American, treated with multiple antirheumatic disease-modifying drugs, or received greater glucocorticoid exposure. The prescription of certain drug classes (loop diuretics and anticonvulsants) and conditions (malignancy, renal insufficiency, alcohol abuse, and hepatic disease) were associated with lower likelihood of GIO prophylaxis, despite putative links between these agents/conditions and osteoporosis. The presence of gastrointestinal disorders dramatically decreased likelihood of GIO prophylaxis. Few characteristics predicted the dispensing of GIO-preventing medications within 7 days of the initial glucocorticoid start date.

CONCLUSIONS

Rates of prescriptions to prevent osteoporosis in a cohort of older men with rheumatoid arthritis on chronic glucocorticoids were low. Gastrointestinal disorders and drugs and disorders potentially linked to osteoporosis are associated with diminished odds of being prescribed GIO-preventing medications.

Internal medicine residents reject "longer and gentler" training

BACKGROUND

Increasing complexity of medical care, coupled with limits on resident work hours, has prompted consideration of extending Internal Medicine training. It is unclear whether further hour reductions and extension of training beyond the current duration of 3 years would be accepted by trainees.

OBJECTIVE

We aimed to determine if further work-hour reductions and extension of training would be accepted by trainees and whether resident burnout affects their opinions.

DESIGN

A postal survey was sent to all 143 Internal Medicine residents at the University of Colorado School of Medicine in May 2004.

MEASUREMENTS

The survey contained questions related to opinions on work-hour limits using a 5-point Likert scale ranging from strongly agree to strongly disagree. Burnout was measured using the Maslach Burnout Inventory, organized into three subscales: emotional exhaustion (EE), depersonalization (DP), and personal accomplishment, with burnout defined as high EE or DP.

RESULTS

Seventy-four percent (106/143) of residents returned the survey. The vast majority (84%) of residents disagreed or strongly disagreed with extending training to 4 or 5 years. Burnout residents were less averse to extending training (strongly agree or agree, 18.9% vs 4.3%, P = .04). The majority of residents (68.9%) disagreed or strongly disagreed with establishing a 60-hour/week limit. Residents who met the criteria for burnout were more likely to agree that a 60-hour limit would be better than an 80-hour limit (strongly agree or agree, 22% vs 8%, P = .02).

CONCLUSIONS

In this program, most Internal Medicine residents are strongly opposed to extending their training to 4 or 5 years and would prefer the current 80 hours/week cap. A longer, less intense pace of Internal Medicine training seems to be less attractive in the eyes of current trainees.

New developments in smoking cessation

Research on smoking has increased in the past several years, and many new therapeutic modalities have been developed. Primary intervention for smoking cessation begins with systematic identification of smokers and a formal diagnosis of nicotine dependence. Providing self-help brochures without clinical advice has marginal efficacy, but these can be useful as an adjunct to clinician intervention. Several large studies have shown that physician advice alone can lead to quit rates of up to 10%, and follow-up for patients trying to quit can double cessation rates. Behavioral therapy alone has demonstrated cessation rates of approximately 20% for those willing to participate. Drug therapy remains the most attractive method of smoking cessation for many patients. The standard approach has been nicotine substitution using one of the four forms of nicotine replacement (gum, patches, nasal spray, inhaler) currently available. The efficacy of nicotine replacement products is similar, with each agent providing a doubling of the cessation rate. Thus, the choice of agent depends on patient factors and preference. Bupropion is the first nonnicotine-containing agent approved for smoking cessation, with cessation rates ranging from 10.5 to 24.4%, depending on dose. One-year follow-up suggests a continued benefit with this agent. The combination of bupropion and transdermal nicotine has also been shown to be effective for smoking cessation in clinical trials. Effective approaches to smoking cessation should combine identification of smokers, provision of advice at each visit, and widespread availability of treatment.

Smokers hospitalized in an urban, public hospital: addiction, stages of change, and self-efficacy

BACKGROUND

This study characterizes adult smokers on the medicine service of an urban, public hospital, including stage of change, self-efficacy to quit, and nicotine dependence, and explores relationships between perceived and actual smoking-related illness and these three predictive variables.

METHODS

Adult patients (n = 154) admitted to the Medicine service of Denver Health Medical Center in October and November 1996 were surveyed using a written questionnaire.

RESULTS

The proportion of smokers in this population was 45.7% (95% CI = 42.0%, 49.4%). Adjusted for age and sex, the proportion of smokers in this population was significantly greater than in Colorado (28.8% vs 21.8%, P < 0.001). About half (54.2%) were willing to try free nicotine patches during hospitalization. Among smokers with diseases recognized as smoking-related, 30.4% believed their reason for admission was related to smoking, compared to 20.4% among those with no smoking-related diseases (P = 0.18). Patients who believed their hospitalization was due to smoking had greater intentions (P = 0.001) and self-efficacy (P < 0.001) to quit.

CONCLUSIONS

Targeting smokers who perceive that their illness is smoking-related may optimize inpatient smoking interventions.

A randomized trial of nortriptyline for smoking cessation

BACKGROUND

Smoking cessation rates with current therapy are suboptimal. One class of drugs that may improve cessation is the tricyclics.

OBJECTIVE

To add nortriptyline hydrochloride to a behavioral smoking cessation program to enhance cessation rates and reduce withdrawal symptoms.

SUBJECTS AND METHODS

We conducted a randomized, double-blind, placebo-controlled trial at an affiliated Department of Veterans Affairs Medical Center and an Army Medical Center. Subjects were aged 18 through 70 years, smoked 10 or more cigarettes per day, and were without current major depression. Nortriptyline hydrochloride or matched placebo was started at 25 mg before bed 10 days prior to quit day and titrated to 75 mg/d or to the maximal tolerated dose. The behavioral intervention consisted of 2 group sessions and 12 individual follow-up visits. Withdrawal symptoms were measured using a daily diary, and smoking cessation was defined as self-reported abstinence, expired carbon monoxide of 9 ppm or less, and a 6-month urine cotinine level of less than 50 ng/mL.

RESULTS

A total of 214 patients were randomized (108 to nortriptyline and 106 to placebo). There was a significant reduction in several withdrawal symptoms including anxious/tense, anger/irritability, difficulty concentrating, restlessness, and impatience by day 8 after quit day in the nortriptyline group. The cessation rate at 6 months was 15 (14%) of 108 and 3 (3%) of 106, respectively (P = .003; absolute difference, 11%; 95% confidence interval, -18% to -4%). Nortriptyline caused frequent adverse effects, including dry mouth (64%) and dysgeusia (20%).

CONCLUSIONS

We conclude that nortriptyline led to an increased short-term cessation rate compared with placebo. In addition, there were significant, but relatively small, reductions in withdrawal symptoms. Nortriptyline may represent a new therapeutic approach to smoking cessation.

The assessment of refill compliance using pharmacy records: methods, validity, and applications

The refill records of computerized pharmacy systems are used increasingly as a source of compliance information. We reviewed the English-language literature to develop a typology of methods for assessing refill compliance (RC), to describe the epidemiology of compliance in obtaining medications, to identify studies that attempted to validate RC measures, to describe clinical features that predicted RC, and to describe the uses of RC measures in epidemiologic and health services research. In most of the 41 studies reviewed, patients obtained less medication than prescribed; gaps in treatment were common. Of the studies that assessed the validity of RC measures, most found significant associations between RC and other compliance measures, as well as measures of drug presence (e.g., serum drug levels) or physiologic drug effects. Refill compliance was generally not correlated with demographic characteristics of study populations, was higher among drugs with fewer daily doses, and was inconsistently associated with the total number of drugs prescribed. We conclude that, though some methodologic problems require further study, RC measures can be a useful source of compliance information in population-based studies when direct measurement of medication consumption is not feasible.

The safety of transdermal nicotine as an aid to smoking cessation in patients with cardiac disease

BACKGROUND

Transdermal nicotine therapy is widely used to aid smoking cessation, but there is uncertainty about its safety in patients with cardiac disease.

METHODS

In a randomized, double-blind, placebo-controlled trial at 10 Veterans Affairs medical centers, we randomly assigned 584 outpatients (of whom 576 were men) with at least one diagnosis of cardiovascular disease to a 10-week course of transdermal nicotine or placebo as an aid to smoking cessation. The subjects were monitored for a total of 14 weeks for the primary end points of the study (death, myocardial infarction, cardiac arrest, and admission to the hospital due to increased severity of angina, arrhythmia, or congestive heart failure); the secondary end points (admission to the hospital for other reasons and outpatient visits necessitated by increased severity of heart disease); any side effects of therapy; and abstinence from smoking.

RESULTS

There were 48 primary and 78 secondary end points noted in a total of 95 subjects. At least one of the primary end points was reached by 5.4 percent of the subjects in the nicotine group and 7.9 percent of the subjects in the placebo group (difference, 2.5 percent; 95 percent confidence interval, -1.6 to 6.5 percent; P=0.23). In the nicotine group, 11.9 percent of the subjects had at least one of the secondary end points, as compared with 9.7 percent in the placebo group (difference, 2.2 percent; 95 percent confidence interval, -2.2 to 7.4 percent; P= 0.37). After 14 weeks the rate of abstinence from smoking was 21 percent in the nicotine group, as compared with 9 percent in the placebo group (P=0.001), but after 24 weeks the abstinence rates were not significantly different (14 percent vs. 11 percent, P= 0.67).

CONCLUSIONS

Transdermal nicotine does not cause a significant increase in cardiovascular events in high-risk outpatients with cardiac disease. However, the efficacy of transdermal nicotine as an aid to smoking cessation in such patients is limited and may not be sustained over time.

Randomized controlled trial of residents as gatekeepers

BACKGROUND

Managed care advocates suggest that primary care gatekeepers may improve patient care and reduce costs. Training internal medicine residents in these gatekeeping functions has not been emphasized in most internal medicine programs.

OBJECTIVE

To determine if residents could perform gatekeeper functions and if patient costs and satisfaction would be favorable.

METHODS

Patients (n = 254) followed up by residents (n = 26) in continuity clinics at the Denver Veterans Affairs Medical Center in Denver, Colo, were divided into 2 groups. A control group of 128 was followed up by residents with no restrictions on appointments made for them. An intervention group of 126 patients were followed up by residents who had to approve all referrals made for their patients. A research nurse assisted with the approvals when the residents were rotating through other institutions. Utilization of resources, satisfaction with care, and health status were monitored over a 1-year period.

RESULTS

A minor reduction of resource utilization was found in the intervention group, particularly in medication use. Significantly more visits were made to primary care providers in the intervention group (3.01 vs 2.59; P = .03). Patient satisfaction and health status were similar in both groups with a trend toward better satisfaction in the intervention group in some areas.

CONCLUSIONS

Our study showed that residents can function as gatekeepers of highly complex patients and that satisfaction with care and utilization of resources does not suffer. Drug utilization and costs may be less when a gatekeeper exists.

Effects of a postdischarge clinic on housestaff satisfaction and utilization of hospital services

This randomized, controlled clinical trial evaluated the effect of a postdischarge clinic on housestaff education and patient utilization of hospital services. Medicine housestaff were randomized either to attend a clinic once a week in which they saw all eligible patients they had recently discharged from the hospital, or to continue with usual discharge practices. We enrolled 751 patients, 312 on intervention teams and 439 on control teams. Intervention housestaff did not feel that the clinic took too much time and felt that they better knew how patients did after discharge. Fewer intervention patients had emergency room visits (28.0% to 20.8%, p = .03) in the 30 days after discharge. Length of stay, readmission rates, and mortality were similar for the two groups. We conclude that a postdischarge clinic can improve resident education and reduce postdischarge emergency room utilization.

Health care costs of veterans with multiple sclerosis: implications for the rehabilitation of MS. VA Multiple Sclerosis Rehabilitation Study Group

We retrospectively determined health care costs among veterans with multiple sclerosis (MS) and correlated the costs with neurologic dysfunction. Total health care costs for the 165 patients averaged $35,000/year. VA benefits and homecare together accounted for 85% of the total costs. Total health care costs correlated with two measures of neurologic dysfunction, the Expanded Disability Status Scale (EDSS) (r = 0.61, p < 0.001) and the Incapacity Status Scale (ISS) (r = 0.64, p < 0.001). The costs of VA benefits, homecare, and hospitalizations also correlated with the EDSS, ISS, and other measures of neurologic dysfunction whereas the cost of outpatient clinic visits did not. In a period of three years, there were 40 hospitalizations, at a total cost of $412,800, that were potentially preventable with appropriate outpatient management. Improving selfcare and avoiding preventable hospitalizations might lower the considerable health care costs of MS.

Transdermal clonidine reduced some withdrawal symptoms but did not increase smoking cessation

BACKGROUND

Clonidine may be useful in controlling tobacco withdrawal and in facilitating smoking cessation. This study was developed to test the efficacy of transdermal clonidine in promoting smoking cessation.

METHODS

We conducted a five-center, double-blind, placebo-controlled, randomized controlled trial of transdermal clonidine in conjunction with a minimal behavioral intervention for smoking cessation. The intervention was based on the American Lung Association's Freedom From Smoking program. Self report of not smoking was validated with exhaled air carbon monoxide of less than 8 ppm and salivary cotinine of less than 20 ng/mL. Transdermal clonidine therapy began 1 week before the target quit date: 0.1 mg/24 h for the first 4 days increasing to 0.2 mg/24 h for the next 3 days, if the lower dose was tolerated. The highest tolerated dose was then continued for 6 weeks after target quit day. Withdrawal symptoms were measured daily for the first 7 days after target quit day.

RESULTS

A total of 213 patients were enrolled (106 active drug and 107 placebo). During the study, 15.5% of patients had drug therapy discontinued due to adverse effects, 24.5% (26/106) taking active drug vs 8.4% (9/107) receiving placebo. There was a significant reduction in anxiety score from 3.0 to 2.4 (placebo vs active) and irritability score from 2.2 to 1.7 (placebo vs active) during the first week after cessation. There was no reduction in other withdrawal symptoms. The overall 12-week abstinence rate was 33.0% (35/106) in the active drug group vs 34.5% (37/107) in the placebo group (not significant).

CONCLUSION

This study demonstrated some reduction in early withdrawal symptoms with the use of a clonidine transdermal patch, but no increase in cessation rate, 6 weeks after medication had been discontinued.

Leg symptoms in outpatient veterans

In a survey of outpatients at the Denver Veterans Affairs Medical Center for common leg symptoms--515 questionnaires returned in a 3-week period--56% reported nocturnal leg cramps, 29% reported the restless leg syndrome, and 49% reported symptoms of peripheral neuropathy. Only 33% of patients had no symptoms relating to their legs. Patients often did not report these symptoms to their physician but were more likely to do so if the symptoms were frequent. Conditions especially related to leg symptoms were hypertension, peripheral vascular disease, coronary artery disease, cerebrovascular disease, kidney disease, and hypokalemia. Most patients did not receive effective therapy for these symptoms.

Dyslipidemia in veterans. Multiple risk factors may break the bank

The National Cholesterol Education Program guidelines for treatment of high cholesterol levels especially target patients who have multiple risk factors for coronary heart disease. Veterans have an increased prevalence of smoking, are predominantly male, and may have higher rates of other risk factors than other groups; therefore, they may require more aggressive screening and treatment for dyslipidemias. To assess the prevalence of cardiac risk factors, current cholesterol screening practices, and the potential impact of the National Cholesterol Education Program guidelines on the Veterans Affairs health care system, we reviewed 185 randomly selected charts of outpatients who were actively receiving follow-up at the Denver (Colo) Veterans Affairs Medical Center. The patients had an average age of 58.3 years and 99.5% were male. Of these patients, 60% had a serum cholesterol level checked within the last 999 days. Nearly all patients (84%) had two or more risk factors noted. The mean cholesterol level was 5.85 mmol/L (226 mg/dL), with 72% of patients having levels above 5.20 mmol/L (200 mg/dL) and 36.1% having levels above 6.20 mmol/L (240 mg/dL). Of patients who had their cholesterol level checked, 69% (77/111) would require lipoprotein analysis by National Cholesterol Education Program guidelines (cholesterol, greater than or equal to 6.20 mmol/L [greater than or equal to 240 mg/dL] or 5.15 to 6.20 mmol/L [200 to 239 mg/dL] with two or more risk factors), yet only 16% (12/77) had lipoprotein analyses done. Extrapolating from these data, the Denver Veteran Affairs Medical Center, which cares for 28,000 patients, has more than 19,000 patients who would need lipoprotein analysis to meet current guidelines. Full evaluation and subsequent treatment of dyslipidemias in veterans would require tremendous financial and manpower commitments.

A survey of physicians' smoking counseling practices

Several techniques used in smoking cessation counseling have been shown to be useful in physicians' efforts to help their patients quit smoking. The use of these techniques by Tulsa physicians was assessed through a survey of private practice internists, internal medicine residents, and family practice residents in a university-based community hospital. The majority of physicians (85%) reported they brought up the subject of smoking with their patients. Other techniques were used less frequently, with 34% of physicians never giving their patients self-help materials, 83% never using a quit date contract, and 73% never making appointments mainly to discuss smoking. Private practice physicians reported using more techniques than did the residents. Internists who practice a subspecialty reported using fewer techniques, and this was especially true in the younger physicians. Ten percent of physicians were often satisfied with their efforts, and 14% had formal training in smoking counseling techniques. Some physicians apparently learn how to better use these techniques as their experience increases. Training physicians while they are in residency and early subspecialty practice may accelerate this process and enable more smokers to quit with their physicians' help.

Reduction of polypharmacy by feedback to clinicians

OBJECTIVE

To determine whether two different educational interventions would reduce polypharmacy in outpatients receiving ten (10) or more active medications at the Denver Veterans Affairs Center.

DESIGN

292 patients were randomized into three (3) groups: Control (n = 88); simple notification of primary care provider (n = 102); intensive notification, provision of pharmacy profiles, compliance index, and chart review by senior clinician with recommendations (n = 104).

SETTING

Veterans Affairs Medical Center affiliated with the University of Colorado Health Sciences Center.

PATIENTS/PARTICIPANTS

All patients receiving greater than ten (10) active medications who are followed by clinic staff at the Denver VAMC. The mean age was 62 years (range 26-88) and 96% were male.

INTERVENTIONS

The simple notification group received only a single letter recommending that the patient's number of medications be reduced. The intensive notification group received more sophisticated intervention with a chart review, two letters with calculation of patient compliance, and individualized suggestions for reduction in polypharmacy. The control group received no intervention.

MEASUREMENTS AND MAIN RESULTS

Control patients had significantly less reduction in polypharmacy then either the simple or intensive intervention groups at four months (p = 0.028). There was no significant difference between the intervention groups (p = 0.189). By six months the difference was no longer significant.

CONCLUSIONS

A simple intervention can result in a significant reduction in the number of medications prescribed to patients with polypharmacy. The authors were unable to show that a more complex intervention resulted in a further reduction in polypharmacy.

Pursuing mild elevations of liver enzyme values to exclude hemochromatosis

To determine whether physicians in an academic medical center excluded hemochromatosis as a diagnosis in a population of patients with mildly elevated liver enzyme values, we reviewed 100 charts of patients with both aspartate aminotransferase and alkaline phosphatase levels that were less than twice the upper limit of normal. We analyzed each chart to determine if hemochromatosis would have been excluded by a subsequent workup. Those patients who did not have a complete workup were assigned to one of three categories: (1) no mention was made of abnormal liver enzyme values; (2) liver enzyme values were ascribed to some condition other then hemochromatosis and no definitive workup was done; and (3) the condition of the patient was so poor that assessment did not seem indicated. Ninety of 100 patients were not given a workup to exclude hemochromatosis. Physicians often ignore mild elevations in liver enzyme values.

Research consent forms: continued unreadability and increasing length

Consent forms are often long and incomprehensible. The authors studied 88 consecutive research consent forms generated at the Denver Veterans Administration Medical Center, evaluating the reading levels of the forms using the Fry Readability Scale and recording the numbers of lines of text. The mean grade reading level required for comprehension was 13.4 years of schooling. Twenty-two percent of all text passages scored were at the postgraduate level of readability. This difficult readability level has not improved since the forms were last tested in 1982. The mean length of the forms was 84.6 lines. Also found was a 58% increase in the length of forms since 1982, a factor known to impair comprehension. These factors, poor readability and increasing length, may make many consent forms incomprehensible. It is recommended that investigators be brief, use plain English, and write consent forms at appropriate reading levels, and receive training on how to obtain valid consent.

How physicians can help their patients quit smoking. A practical guide

We describe practical, effective, office-based methods for physicians to use to assist patients to stop smoking that do not require special training or support personnel. Brief counseling achieves smoking cessation in a small percent of well patients but is more effective in patients with smoking-related illnesses or abnormal laboratory test results. Routine prescribing of nicotine gum without participation by the patient in a smoking-cessation program does not increase smoking cessation, and we do not recommend it. The prevention of smoking relapse can probably be enhanced by scheduling follow-up office visits after the patient has quit. Failure to quit on initial attempts should not discourage physicians and patients, since most successful abstainers usually must make several attempts to quit. We outline for physicians two approaches, one brief and one more intensive, to help patients stop smoking.

Osler's Maneuver in outpatient veterans

A recently described procedure, Osler's Maneuver (OM), identifies patients with pseudohypertension. We examined the prevalence of OM positivity in consecutive outpatients at a Veterans Administration Medical Center. A total of 582 patients, median age of 61 years, were studied. OM was definitely positive in 3.4% (20/582). Age strongly related to OM (p less than 0.001). No patients under 50 were positive, while 15.6% (29/186) of those age 65 or older had a possible or definite OM. OM positive patients had higher systolic pressures than did OM negative patients (p less than 0.001). There was no significant relation between OM and diastolic pressure. In a regression analysis, definite or possible OM was associated with higher systolic pressure (p = .001). A moderate degree of observer variation in detection of OM was present (kappa = .675). OM positivity is common among the elderly, and so, pseudohypertension may occur more frequently than has been previously recognized.

Primary thrombocythaemia treated with busulphan

Thirty-seven patients with primary thrombocythaemia (PT) treated with busulphan have been followed for periods up to 25 years. Reduction of the platelet count to less than 400 X 10(9)/l resolved vascular occlusive symptoms, but haemorrhagic symptoms often remained unaltered. Cox regression analysis indicated that there were only two prognostically important presenting features; age had a strong inverse correlation with survival and vascular occlusive symptoms correlated with a better survival. Median duration of survival on treatment was 9 X 8 years. The number of deaths was 2 X 1 times that of a comparable control group, with deaths from myelofibrosis markedly increased. Deaths from thrombosis and malignant diseases, including leukaemia, were not significantly different from the number expected, which emphasizes the efficacy and the relative safety of busulphan for the long-term treatment of PT. Progression of PT into myelofibrosis occurred in 24% of cases and 9% became polycythaemic. Two additional cases of "thrombocythaemia' with a Philadelphia chromosome (and no overt evidence of chronic granulocytic leukaemia) are also presented.

The epidemiology of polycythaemia rubra vera in England and Wales 1968-1982

The epidemiology of polycythaemia rubra vera (PV) has not been studied extensively in the past. In 1968 PV became subject to cancer registration in England and Wales. The mortality rates and registration rates for PV were abstracted for 1968-1982. The average annual mortality rates were 3.0/million/y (men, 1068 cases) and 2.3/million/y (women, 886 cases), there being no significant increase over the time period. The average annual registration rates were 10.7/million/y (men, 3321 cases) and 6.7/million/y (women, 2207 cases) and showed a large increase from 1968 to 1974 with a stable rate subsequently. This increase was concentrated in the 65+ age groups. The median age of registration was 60--64 y with a peak of mortality and incidence between ages 75 and 84 y. The data suggest some degree of overdiagnosis for PV registrations, however the rates are comparable with those seen in other studies in developed countries. The routine data sources require further validation, but they appear to provide useful information for the study of the epidemiology of PV.