TC led to a greater decrease in systolic and diastolic BP  than UC .
The differences between TC and UC for systolic BP tend to become larger when no treatment modification is applied .
TC seems a valuable tool for hypertension management
There is an increasing interest for using telecare(TC ) in the management of hypertension .
Home Monitoring Service Improves Mean Arterial Pressure in Patients with Essential Hypertension
Although the use of telecommunication systems in medicine has been increasing , few trials have assessed the efficacy of such technology for improving blood pressure in patients with essential hypertension ( 1 , 2 ) . Friedman and colleagues ( 1 ) found that when hypertensive patients used a telephone-linked computer system to report blood pressure , diastolic blood pressure decreased significantly . Bondmass and colleagues ( 2 ) also found a significant decrease in both diastolic and systolic blood pressure , although their trial lacked controls . In these studies and in other trials of home monitoring , self-report of blood pressure was the basic mechanism for transmission of information to physicians ( 1 - 8 ) . This may have consequences for patient care , since it has recently been shown that patients often erroneously report blood pressure , especially patients whose blood pressure is uncontrolled ( 9 ) . Johnson and colleagues ( 9 ) found that in approximately 20 % of instances , self-report of blood pressure differed from the electronic reading by more than 10 mm Hg . Another limitation of previous trials is accurate assessment of the outcome . In some studies , the outcome was determined by one or two blood pressure readings taken during an office visit or by a technician in the home setting ( 1 , 4 - 7 ) . Only one study of 31 patients used  automatic ambulatory blood pressure monitoring ( ABPM )  to assess usual blood pressure at baseline and exit ( 3 ) . Twenty-fourhour ABPM recordings yield a more reliable assessment of usual blood pressure levels during the course of daily activities ( 10 ) . To improve on the previous studies , we design ed a r and omized , controlled trial that used 24-hour ABPM measurements at baseline and at exit to determine change in blood pressure more accurately . The intervention was a service provided to physicians that used electronic transmission of results and did not rely on  self-report of blood pressure . Methods Study Protocol From May 1999 to April 2000 , five internists from the Department of Medicine at the State University of New York Upstate Medical University in Syracuse recruited patients from internal medicine outpatient practice s affiliated with the general medicine division . Out patients seen by these physicians were covered by private insurance plans or Medicare . Eligible patients were adults who had previously received a diagnosis of essential hypertension and were under evaluation for a change in antihypertensive therapy because of 1 ) elevated blood pressure [ systolic pressure 140 or diastolic pressure 90 mm Hg ] despite current antihypertensive therapy , 2 ) undesirable side effects of current antihypertensive medication , or 3 ) office systolic pressure of at least 180 mm Hg or diastolic pressure of at least 110 mm Hg with no current use of antihypertensive medication . For patients with diabetes mellitus , heart disease , stroke , nephropathy , peripheral arterial disease , or hypertensive retinopathy , an office systolic pressure of at least 130 mm Hg or an office diastolic pressure of at least 85 mm Hg was a criterion for eligibility . Patients who were younger than 18 years of age , were pregnant , had secondary hypertension , or did not have the mental or physical capacity to monitor blood pressure at home were excluded . All patients were informed of the study procedures , the risks and benefits of participation , confidentiality , rights , and personnel to contact for additional information . The institutional review board at Upstate Medical University approved the trial , and all patients gave written consent before participation . Patients received printed educational material s on nonpharmacologic approaches to blood pressure  control from the National Heart , Lung , and Blood Institute ( 11 ) . These approaches included reducing weight , increasing physical activity , and changing diet if necessary . At baseline , height and weight were recorded at the clinic for all patients . Body mass index was calculated as kg/m2 . Printed information on the treatment of hypertension from the Sixth Report of the Joint National Committee on Prevention , Detection , Evaluation , and Treatment of High Blood Pressure ( National High Blood Pressure Education Program ) ( 12 ) was available at each clinical site as a reference for physicians and clinical staff . Study Group Assignment We conducted a r and omized trial with concurrent controls . The two study groups were home service and usual care .  To ensure an equal number of patients in both study groups , we used a blocking procedure with r and om permuted blocks of varying size to reduce predictability . R and omization was stratified by the number of prescription medications patients were taking ( 0 to 2 or 3 ) at study entry , which served as a general indicator of morbidity . Sequentially numbered , sealed , opaque envelopes were used for assignment . The r and omization procedure was concealed to physicians and clinical research staff , but physicians , investigators , and patients were aware of group assignment when r and omization was complete . In addition , adherence to the protocol was monitored independently of the clinicians . A priori sample size was calculated to detect a mean ( SD ) difference in blood pressure of 3 5 mm Hg between the two study groups . This yielded 60 patients per group with 90 % power ( = 0.05 [ two-tailed ] ) . Intervention The intervention was a telecommunication service consisting of three components : automatic blood pressure recording at home , central processing , and electronic reports provided weekly to the primary physician and patient . We used a home blood pressure monitoring device that transmitted data over analog telephone lines ( Model 52500 , Welch Allyn , Inc. , Skaneateles Falls , New York ) and was vali date d according to the st and ards of the American National St and ard Institute , Inc. , and the Association for the Advancement of Medical Instrumentation ( 13 ) . The oscillometric device ( 16.26 cm 10.92 cm 6.6 cm ) had a digital display for blood pressure and pulse and used automatic pressurization and exhaust for cuff inflation and deflation . Patients were instructed to take their blood pressure three times in the morning before eating or drinking and three times in the evening before going to bed . After each reading , the device automatically dialed the Service and Support Center at Welch Allyn and transmitted the data . Patients were asked to conduct this routine at least three days each week for a minimum of 8 weeks and could take additional readings if they desired . A computer program was developed to display the results in a report form , which was then faxed to each patient 's physician . The report form contained information on the mean systolic pressure , mean diastolic pressure , and heart rate ( overall , morning , and evening ) . It also graphed the pressure by date and displayed individual readings in tabular form . Both physicians and patients received a report form each week , as well as a summary report form at the end of the trial . When physicians received report forms that indicated elevated pressure , they adjusted antihypertensive medications through a telephone call , an office visit , or both . At the time of the trial , the service cost $ 24.95 per month . Patients assigned to usual care were treated for hypertension according to the guidelines of the Joint National Committee on Prevention , Detection , and Treatment of High Blood Pressure ( 12 ) . Question naire Information Information about patients ' medical histories , past diagnoses of disease , and use of medications was obtained from question naires . The Baecke question naire of habitual physical activity was used to assess usual activity levels ( 14 ) . Subscales included a work index , a sports index , and a nonsports leisure index , as well as a total physical activity score . Dietary intake was estimated by using the Block screening question naire , which consists of two subscales : intake of highly saturated fatty foods and intake of fruit , vegetables , and high-fiber grains ( 15 ) . Questions about smoking and stress were taken from the previously vali date d Health Habits and History Question naire ( 16 ) . The study question naire was collected at the time of the second 24-hour ambulatory readings . Outcome Measures The primary end point was the change in mean arterial pressure during the trial ( baseline to exit ) for home service compared with usual care . A clinical research nurse ( the study manager ) fitted participants with a 24-hour ABPM device at baseline and at exit . The nurse gave the patients detailed instructions for using the device . The ABPM device automatically recorded blood pressure every half-hour from 7:00 a.m. to 11:00 p.m. and every hour from 11:00 p.m. to 7:00 a.m. Information from baseline and exit ABPM readings was given to physicians only after the patient exited the trial . All blood pressure measurements indicated in this report refer to these 24-hour readings . Means and SDs were recorded for systolic pressure , diastolic pressure , arterial pressure , and heart rate by using 24-hour ABPM . Mean arterial pressure was measured as ( diastolic pressure + 1/3 [ systolic pressure diastolic pressure ] ) . The ABPM device also recorded the percentage of readings above the desired target levels ( 140 mm Hg systolic or 90 mm Hg diastolic for patients without target organ damage ; 130 mm Hg systolic or 85 mm Hg diastolic for patients with target organ damage ) . Patients were scheduled to remain in the trial for a minimum of 8 weeks . During the sixth and seventh weeks , appointments were made to schedule second 24-hour ABPM sessions . For both the home service and usual care groups , the median time from baseline to exit was 11 weeks . The final patient receiving usual care exited at 20 weeks , and the final patient receiving home service exited at 28 weeks . Statistical Analysis All information was entered into an Excel data base ( Microsoft Corp. , Redmond , Washington ) and was manually rechecked for errors . Statistical analyses were conducted by using STATISTICA software (
TC led to a greater decrease in systolic and diastolic BP  than UC .
The differences between TC and UC for systolic BP tend to become larger when no treatment modification is applied .
TC seems a valuable tool for hypertension management
There is an increasing interest for using telecare(TC ) in the management of hypertension .