Intervención para valorar la Inercia Terapéutica en el tratamiento de la hipertensión arterial

  1. María Ángeles Garrido López
Supervised by:
  1. Carlos Ruiz Frutos Director
  2. Josefa Borrero Hernández Director
  3. Emilio Márquez Contreras Director

Defence university: Universidad de Huelva

Fecha de defensa: 18 December 2014

  1. Emilio Pujol de la Llave Chair
  2. Nieves Martell Claros Secretary
  3. Vicente Gil Guillén Committee member

Type: Thesis


Therapeutic Inertia has been defined by Phillips as the failure of the physician to start or to intensify treatment when it is indicated. It is a conservative attitude on the part of the clinician, in which the treatment is not modified despite the fact that it is not achieving the therapeutic objectives. Therapeutic Inertia is a serious problem that affects all healthcare and which is difficult to resolve, as this requires better training for healthcare professionals and a greater awareness in the application of guidelines and consensuses in High Blood Pressure. Above all, it is incentives for healthcare professionals and the availability of time in the management of their consultations that are lacking. If we analyse the therapeutic inertia that occurs in Spain, we see that transversal studies put it at between 51% and 84,6%, while longitudinal studies put it at between 40,3% and 82,5%. The latter are more similar to everyday clinical practice. Furthermore, therapeutic inertia occurs in more than 80% of non-controlled hypertensive patients, which indicates the great importance of this phenomenon in the normal practice of healthcare professionals. There are few studies in the literature that evaluate interventions with the aim of reducing therapeutic inertia. It is for this reason that it is pertinent to evaluate whether interventions have the capacity to reduce it in normal clinical practice. OBJECTIVES OF THE STUDY PRIMARY OBJECTIVE To evaluate whether a nursing consultation is an effective strategy to reduce Therapeutic Inertia in the pharmacological treatment of High Blood Pressure. SPECIFIC OBJECTIVES To measure the prevalence of Therapeutic Inertia occurring in the pharmacological treatment of High Blood Pressure in primary-care consultations. To evaluate the existence of different variables that could influence Therapeutic Inertia and the influence of Therapeutic Inertia on Blood Pressure figures. METHODOLOGY The study was carried out in a primary care environment in the various healthcare districts of the province of Huelva, in south-western Spain. 206 patients with mild to moderate HBP, according to the criteria of the ESC/ESH 2007 Guidelines, took part. They were divided into two treatment groups, with 6 months� follow-up for each patient. Of the 110 doctors in the eleven healthcare districts to who the study was proposed, 30 took part. Each doctor selected 7 patients consecutively as they detected hypertensive patients in their practice who met the inclusion criteria and none of the exclusion criteria. The methodology that was used for the calculation of sample size was that for studies that obtain proportions as principal results and that need a two-tailed test. An observation of a 26% difference in therapeutic inertia between the groups was considered to be clinically significant, and the prevalence of Therapeutic Inertia in the control group was estimated at 65%. Possible losses to follow-up of 10% were considered, giving a sample of 103 individuals for each of the two groups. Therefore the final sample size was 206 patients. A cluster randomisation was carried out to the participating doctors, with a doctor�s patients being assigned to the group to which he/she corresponded. The randomisation was carried out centrally using random-number tables by a person who was not involved in the follow-up of patients. WORKPLAN The study lasted 12 months, with an inclusion period of 6 months. Two groups were obtained after the randomisation of the doctors; Control group (CG): The patients received the treatment that their primary-care doctor usually applies in the practice for the management of hypertensive patients and were NOT previously seen in appointments with a nurse. Treatment group or nursing-consultation group (NCG): The patients received their primary-care doctor�s normal treatment and, in addition, were followed up through appointments with a nurse to monitor blood pressure figures. In these appointments, these patients received the normal treatment practiced by their nurse with his/her hypertensive patients normally. An initial visit and visits at 2, 4 and 6 months were carried out. For these appointments, a medical referral form was available to be used for patients who presented high blood pressure figures according to the health centre�s protocol and the judgement of the nurse. Three medical visits were carried out: the initial or inclusion visit, a follow-up visit at the health centre after 3 months, and a final visit 6 months after the inclusion visit. VARIABLES AND STATISTICAL ANALYSIS The variables studied were: the total number of individuals, drop-outs and their reasons, age and gender, number of illnesses and medicines taken, associated Cardiovascular Risk Factors, clinical mean Blood Pressures and their standard deviations and the differences in blood pressure between two consecutive visits and the initial and final visit. The degree of control of Blood Pressure was calculated, considering BP to be controlled when the clinical mean systolic and diastolic pressures were lower than 140 mmHg and 90 mmHg respectively. Therapeutic Inertia was defined at each visit by the ratio: (Number of patients whose pharmacological treatment was not changed / Number of patients with mean clinical blood pressure figures higher than 140 mmHg and/or 90 mmHg) multiplied by 100. The Therapeutic Inertia was calculated for the clinical visits at 3 and 6 months. The therapeutic Inertia at the visits was considered to be the principal variable. The sample was divided into two groups depending on the therapeutic inertia that occurred: patients with Therapeutic Inertia and patients without Therapeutic Inertia. The differences in variables that could influence Therapeutic Inertia were evaluated by carrying out a bivariate and multivariate analysis with logistic regression of said variables. The degree of control of blood pressure was calculated in relation to the Therapeutic Inertia that occurred, i.e. for the group of patients without therapeutic inertia and for the group of patients with Therapeutic Inertia. The absolute risk reduction (ARR = difference between the rates of therapeutic inertia in the nursing-consultation group and in the control group), the relative risk reduction (RRR ~ ARR divided by the rate of therapeutic inertia in the control group) and the number of patient who would need to be treated to avoid one case of therapeutic inertia (NNT = 1/ARR). All the variables were evaluated using the statistical software package SPSS 11.5 for Windows and were then calculated and compared, first overall and then by treatment groups. Tiie relationship between Blood Pressure and the degree of control of Blood Pressure with Therapeutic Inertia was analysed. The correlation between Therapeutic Inertia and Blood Pressure figures was evaluated using multiple linear regression analysis. The Chi-squared test, Student�s Mest and McNemar's test were used for the comparison of qualitative and quantitative variables for paired and unpaired data. A p<0,05 was considered significant and confidence intervals (Cl) were calculated at 95%. RESULTS A total of 184 patients finished the study, 92 patients from each treatment group could be evaluated. The overall mean age was 62,8 years; there were 58,5% women with a mean age of 63,4 years and 41,5% men with a mean age of 62 years. By treatment groups, the mean age of the Nursing-Consultation Group was 62 years and that of the Control Group 63.7 years. Patients suffered from an average of 2,9 illnesses and took an average of 4,1 medicines every day, including other medicines not indicated for HBP: there was no difference between genders. There was no significant difference between the cardiovascular risk factors studied except for dyslipidaemia, which was presented by 33,8% of patients in the nursing- consultation group and 49,3% of patients in the control group. The mean Blood Pressures showed a significant reduction between the initial and final visits, with drops of 18.7 mmHg in systolic pressure and 9,6 mmHg in diastolic pressure. The drops achieved between the start and the end of the study were statistically significant for the mean systolic pressures and the pulse pressures, with this drop being higher in the Nursing-Consultation Group. The proportion of individuals controlled at the end of the study was 60,6%. It was observed that the proportion of responding and controlled individuals increased as the study went on (p<0,001). Significant differences were observed in terms of the degree of control of the blood pressure figures at each visit, over all and as a function of treatment group, with greater control at the final visit in the treatment group. The Therapeutic Inertia level at visit 2 was 15,5% in the treatment group and 38% in the control group; for the final visit it was 25,23% and 46,07% for the treatment group and the control group respectively. The Therapeutic Inertia level in non-controlled hypertensive patients in the treatment group was 22,9% at visit 2 and 54,5% at the final visit, and was higher in the control group (57,5% at visit 2 and 76,5% at the final visit). This difference was significant for visit 2 (p=0,04). The sample was divided into patients with and without Therapeutic Inertia: there were 49 patients with Therapeutic Inertia and 133 without. The possible influence of various variable on Therapeutic Inertia was analysed. After two-tailed analysis, statistically significant differences were only observed in two variables: Therapeutic Inertia is higher with a higher number of illnesses suffered (95% RR for illness suffered, p=0,002) and with a lower number of medicines taken (95% RR for medicines taken, p<0,001). The proportion of patients controlled at the end of the study was 38,51% in the group without Therapeutic Inertia and 18,36% in the group with Therapeutic Inertia (p<0,05). The systolic blood pressure was observed to be lower in the group without Therapeutic Inertia than in the group with Therapeutic Inertia (p<0,05). The absolute risk reduction at the end of the treatment was 22,5%. The relative risk reduction was 59% and the number of patients needing to be treated was 4,44. It would be necessaiy to treat 4 patients with this protocol to avoid one case of therapeutic inertia. CONCLUSIONS The nursing consultation is an effective strategy to reduce cases of Therapeutic Inertia by primary-care doctors in the pharmacological treatment of high blood pressure. The prevalence of Therapeutic Inertia is high. In this study it ranges from 15,5% to 46,07% depending on the visit and the group referred to. The number of medicines taken (number of tablets/day) and the number of illnesses suffered influence Therapeutic Inertia: it is higher when fewer medicines are taken and when more illnesses are suffered. Lower Therapeutic Inertia translates into better control of High Blood Pressure.