Evaluation of actions concerning systemic arterial hypertension in primary healthcare

OBJECTIVE: To evaluate the effi ciency of the Family Health Strategy in actions related to hypertension. METHODS: Evaluative, cross-sectional quantitative research based on secondary data of 66 small municipalities located in the state of Santa Catarina, Southern Brazil, with maximum potential coverage of 100% by the Family Health Strategy in 2007. Input indicators, products and results were evaluated. The municipalities’ effi ciency of services production and results production was compared through data envelopment analysis. RESULTS: The municipalities were more effi cient in services production (37.8%) than in results production (16.6%). Forty-one municipalities (62.2%) were ineffi cient in the services: enrolment in the Hypertension and Diabetes Information System, individual assistance and home visit for hypertensive users, and 55 (83.3%) were ineffi cient in the production of impact against hypertension. CONCLUSIONS: The evaluation model used in this study proved to be capable of measuring effi ciency in primary healthcare by evaluating the productivity of services and results. DESCRIPTORS: Hypertension, prevention & control. Family Health Program. Health Services Evaluation. Primary Health Care. CrossSectional Studies.


INTRODUCTION
Public expenditure on health is increasing and is related to factors such as population aging, new health technologies, improvement in income levels, consolidation of the wellbeing state and universalization of sanitary coverage.a In these circumstances, the use of economic methodological instruments in the fi eld of health is justifi ed by the criterion of scarcity and by the diffi culty in resources allocation. 16ta envelopment analysis (DEA), created in the 1980s, measures productive effi ciency in the social area.It was developed to evaluate public programs in such a way that the organizations' fi nancial aspect is not the only one that is considered.This tool is applied to studies on the productivity and technical a Ministério da Saúde.Secretaria-Executiva. Área de Economia da Saúde e Desenvolvimento.Avaliação econômica em saúde: desafi os para gestão no Sistema Único de Saúde.Brasília (DF); 2008.
effi ciency of productive units that employ multiple inputs to generate multiple products, and it enables to identify the best practices by means of empirical frontiers of linear programming. 6nce its implementation, Sistema Único de Saúde (SUS -National Health System) has dealt with lack of resources, given the adverse scenario from the economic point of view at the time it was created.Programa Saúde da Família (PSF -Family Health Program) emerged in light of the initial criticism of being a care program that had restrictive characteristics.However, its rapid expansion in the last years and its importance have transformed it in a conversion strategy of the primary healthcare model.The control and diagnosis of hypertension have been an attribution of the Family Health Program, have a character of priority action in the adult's health in its initial phase and have become a strategic action after the Pacto em Defesa da Vida (Pact for Life Defense), of 2005. 1 Systemic Arterial Hypertension (SAH) is a highly prevalent chronic non-communicable disease whose diagnosis and control are fundamental in the handling of serious diseases like congestive heart failure, cerebrovascular diseases, acute myocardial infarction, hypertensive nephropathy, peripheral vascular disease and hypertensive retinopathy.
Evaluation of the effi ciency of SAH-related services, with the identifi cation of strong points of action of reference municipalities, could represent an important management and planning tool.It would enable the improvement in the provided care by identifying municipalities and actions with effi cient impact, thus subsidizing information on how to produce services and results with more effi ciency.The present study aimed to evaluate the effi ciency of Estratégia Saúde da Família (ESF -Family Health Strategy) in the actions related to hypertension.

METHODS
In the study, 66 small municipalities located in the state of Santa Catarina, Southern Brazil, were selected, whose model of Atenção Primária à Saúde (APS -Primary Healthcare) was ESF for the entire population.An evaluative model was constructed as recommended by Rabetti (2009).b The data were organized into SAH-related inputs and products in primary healthcare.Financial resources, material resources and workforce were considered inputs for services production, and actions for SAH control and diagnosis, as products.The generated services were transformed into inputs, and their product was the control of the immediate and mediate health conditions deriving from SAH (Figure 1).The inputs were: fi nancial resource (the total amount employed by the municipality to defray the cost of primary healthcare); material resource (weekly hours of occupation of offi ces destined to primary healthcare), and workforce (average weekly working hours of the Family Health teams per month).
Enrolment (number of enrolled individuals with SAH); individual assistance (number of SAH assistances performed by the ESF), and home visit (number of visits of community health agents to users with SAH) were the considered services.
The SAH-related services performed by ESF were classifi ed as inputs in the stage of results production.The number of observed services was corrected to number of services projected for effi ciency by the DEA tool, in order to maintain the relationship with the initial inputs.
A result indicator or rate was created that represented protection to cardiovascular (CV) outcomes.This rate was called rate of SAH-related hospitalizations potentially avoided by primary healthcare, calculated by the formula: rate = [(population between 20 and 65 years -number of hospitalizations due to SAH, Congestive Heart Failure and Cerebrovascular Diseases in individuals between 20 and 65 years): population between 20 and 65 years] * 10,000.
DEA was employed to construct empirical frontiers of productive effi ciency, that is, a grouping of the best observed productivities, forming a set of units of maximum productivity, and no productive unit is above this limit.One of its greatest advantages is the identifi ed effi ciency, which is real and not calculated as a theoretical combination of the best that could be done in ideal conditions.c In the DEA methods, the units of analysis are evaluated according to the utilization of inputs for the production of a certain amount of products.Weights are attributed to each input and to each product aiming at a more effi cient relationship.
DEA was chosen due to the possibility of complex analyses for multiple inputs and multiple products; because it does not require predetermined existence of a mathematical model that relates inputs and products (the only maintained hypothesis is that the weighted sum of inputs and products of any municipality results in a "virtual municipality" of viable technology); because it compares units directly with their pair or with a combination of pairs; and because inputs and products can be expressed in different units (for example: number of employed teams and invested values in reais). 8A's main limitations are the measurement errors and the presence of outliers, which interfere in the formation of the frontier.Due to this, checking for the presence of infl uent observations and outliers is recommended. 8strictions were established to control for the municipalities' heterogeneity and to ensure they would be structurally comparable: same size (≤ 10 thousand inhabitants) and same ESF coverage (100% of maximum potential coverage).To control for outliers, 37 municipalities (35.9%) were excluded due to lack of data or to measurement errors that could not be corrected.DEA was applied to the two productive stages by means of the program IDEAS®.c The variable scale model was used, in light of the hypothesis that variation in the municipality's size might interfere in the production scale of services and results.DEA was oriented to products, with the arrangement of invested inputs, which searched for the best productivity and increased the number of products.
The maximum productivities that were observed formed an empirical frontier of effi ciency among Santa Catarina's small municipalities.Maximum productivity assumed a score equal to 1 and was classifi ed as efficient; scores above 1 were categorized as ineffi cient.
By means of DEA, effi cient productivity goals were calculated to the ineffi cient units and ineffi ciency for each product was evaluated.

RESULTS
Of the 66 municipalities, 25 (37.8%) were effi cient in the production of services related to SAH and 41 were ineffi cient (62.2%).
The scores of the ineffi cient municipalities ranged from 1.06 to 2.09 (productivities 0.6 to 1.9 lower than the maximum productivity that was observed).The effi cient municipalities with similar input arrangements were able to produce more services and became reference to the others.
Municipalities that were considered ineffi cient had more than one municipality as reference.Table 1 shows the benchmarks in services and the characteristics of their practices.The total of references was higher than the total of observations, because there were municipalities with more than one reference.
Five municipalities were reference only to themselves, i.e., the others did not obtain projections for their practices from their arrangements.
Of the municipalities, 41 were ineffi cient concerning the production of the three types of services: user enrolment, individual assistance and home visit (Table 2).
The greatest inefficiency was in user enrolment, measured by the record of users with SAH in SISHIPERDIA, with an average of 47.3% in the state.The number of enrolled users was incompatible with the other activities observed in some municipalities (Table 2).The municipality of Irani, the most inefficient one, had three enrolled users when it should have 312; however, it offered 7,623 individual consultations regarding this activity, and a little more than 10 thousand home visits, which suggests a specifi c defi ciency in user enrolment.
The municipalities needed to expand production by 43.16% on average for individual assistance.The municipality of Paial had the highest ineffi ciency in individual assistance, having offered 48 consultations for users with SAH in one year.In order to become effi cient, its productive goal was of 896 consultations/ year, which would mean a 94.7% increase in this product.Ineffi ciency was lower in the other services (approximately 40%) for this municipality.The lowest degree of ineffi ciency was observed for home visits.Santiago do Sul was the most ineffi cient municipality in home visits, with 998 visits and a goal to achieve effi ciency of 3,414.The ineffi ciency of this municipality was equally distributed among the three services.
The effi ciency frontier in results production was constituted of fewer municipalities than the services frontier.
The scores of the ineffi cient municipalities were close to 1, which suggests that their maximum productivity was almost reached.The variation of the ineffi cient scores was of 1.000014 to 1.006635.
Of the 11 effi cient municipalities in results production, nine (81.9%) became reference for other ineffi cient ones.Two (18.1%), despite being effi cient, had no municipalities that could be projected for their practices (Table 3).The municipality of Jaborá was the one that most served as reference (36 municipalities can achieve its results without modifying their inputs).This benchmark presented two hospitalizations for the selected causes.Thus, 9,991 every 10 thousand people of the susceptible population were protected from CV outcomes, which indicates that the services developed by the ESF protected this part of the population.This rate applied to the susceptible population showed that there was the maximum protection that the service could obtain.
In the ineffi cient municipalities, on average, 18:10,000 adults were not protected from CV outcomes and were hospitalized due to avoidable causes that were sensitive to SAH-related primary healthcare (Table 4).To be continued In Bom Jardim da Serra, the municipality that had the highest ineffi ciency in results production, the number of avoided hospitalizations might be increased by approximately 66 adults every 10,000.Considering its adult population, 15 people might have been protected and would not have been hospitalized due to SAH, congestive heart failure or cerebrovascular diseases.The value observed in this city was of 17 hospitalizations, when it could have reduced the number of hospitalizations to two to be effi cient.
Of the 11 effi cient municipalities in results production, nine (81.9%) were effi cient also in the production of SAH care services with impact (p = 0.001) (Table 5).

DISCUSSION
The evaluation model developed in the present study proved to be capable of measuring effi ciency in primary healthcare by evaluating the productivity of services and results.
The employed methodology can be a useful tool for municipal managers concerning the reorientation of primary healthcare in the search for effi ciency.It enables to identify types of underused resources, the increase in services that might occur with the utilized resources and the potential of avoidable hospitalizations as a consequence of SAH.
The selection of SAH-related hospitalizations due to causes that are sensitive to primary healthcare and their transformation into potentially avoidable hospitalizations in the susceptible population resulted in the creation of the rate of potentially avoided hospitalizations, a marker of the impact of primary healthcare.Its employment proved to be useful to evaluate the effi ciency of results.
The present study evaluates a level of care that has an extensive action spectrum, but it focuses on the set of services related to SAH control, which can be considered a limitation.Camargo Jr et al 4 state that evaluation can be restricted to certain conditions or pathologies considered "representative" of the responsibilities of the assistance system.Therefore, many studies on health systems, programs or services use these "tracers" as a way of evaluating the whole of a program.
Assistance to SAH is not exclusive of primary healthcare, but the best opportunities of action happen in this level of care.The hypertensive disease can be considered a "tracer" of Family Health, as it is a health condition that is prioritized in the adult health care and, although it is a specifi c disease, it is also characterized by the need of longitudinal care, which is characteristic of primary healthcare. 17en the productivity of this action was evaluated, no exclusive inputs for this health condition were found.The municipality is considered ineffi cient concerning a specifi c action and not the action of the ESF as a whole, as the inputs are shared for all actions executed in this level of care.
Another restriction of the study regards the utilization of secondary data.The utilization of data from the Sistemas de Informações em Saúde (SIS -Health Information Systems) should be made with caution and critical analysis, as the risk of under-recording and the low quality of the data are well known.
Authors of baseline studies on primary healthcare disagree on the theme.Camargo Jr et al 4 analyzed three information systems and concluded that SIAB has adequate coverage and reliability and that these data should be used in order to value the information systems and to stimulate their use as monitoring and evaluation instruments.Fachini, 9 on the other hand, argues that the information provided by the SIS is fragmented, is not updated and its quality is low.According to Cordeiro et al, 7 data from SIAB are not valued by the team's nurse, a fact that may infl uence the quality of their collection, since these professionals are the supervisors of the Community Health Agents. 7Although Brazil has not achieved total excellence in the quality of offi cial data, the qualifi cation of these data has advanced and their utilization contributes to this advance.
It was not possible to evaluate the effi ciency of 37 municipalities due to undernotifi cation or to measurement errors registered in the secondary databases.The qualifi cation of the records, mainly concerning the enrolment of patients in SISHIPERDIA, may improve the evaluations of SAH care in primary healthcare.
The publications on health effi ciency measurement concentrate on analyses of national health systems and hospital services.There are few studies on primary healthcare.
A review study carried out in 2000 on effi ciency frontier studies in primary healthcare identifi ed that such studies emerged after the decade of 1990 and concentrated on a few countries: England, Spain and the United States.There were few studies on primary healthcare when compared to effi ciency studies in the health sector.
Twenty-fi ve publications on the theme were found, of which 21 used DEA as the effi ciency measurement method.Among 12 Spanish studies, the majority used secondary data in the investigation. 14ig-Junoy 14 (2000) criticizes the effi ciency studies in primary healthcare that use only services indicators and do not evaluate their quality, which is shown by the results indicators.According to the author, only two works employed this type of indicator in Spain. 14 the present study, a result indicator was used, as the rate of prevention of hospitalizations due to causes that are sensitive to primary healthcare indicates the obtention of results, the quality of the assistance provided in individualized consultations and home visits, and the user's connection with the healthcare team.
In Brazil, there are few publications on effi ciency in primary healthcare.In a study with inputs, products and results indicators in municipalities located in the state of Ceará, Northeastern Brazil, higher effi ciency was observed in services than in results.In this study, all the executed primary healthcare activities were considered as services indicators and only child mortality and child hospitalization due to diarrhea were considered as results indicators.d This might cause the decrease in the number of effi cient municipalities in results production.This same result was perceived in the present study, Evaluations of effectiveness predominate over efficiency in national and international evaluative research related to programs for control of cardiovascular diseases.These programs were evaluated in primary healthcare in the United States, Norway, Pakistan and Sweden.Although they are applied in different forms, all of them have the objective of reducing cardiovascular risk factors, including SAH. 10,11,13,18 In Brazil, studies on the theme also concentrate on the analysis of effectiveness.In one of them, 98% of adherence and impact of PSF of 57% regarding blood pressure control were observed, with a mean of 10.1, ± 3.9 consultations per year in the state of Bahia, Northeastern Brazil. 2 In São Paulo, effectiveness in one primary care unit (not related to the PSF) was of 44%, with two to four annual consultations. 15One of the benchmarks in services production presented 1.6 individual consultations per year for its patients enrolled in SISHIPERDIA in Santa Catarina.Besides the individual consultations, approximately 27 home visits were performed per year.Petrolândia (Santa Catarina) obtained effi ciency in the results based on these services.
Hospitalization rates due to Conditions that are Sensitive to Primary Healthcare (CSPH) are used as indicator of quality and resolution capacity of primary healthcare in many studies. 5,12Among the ineffi cient municipalities, 387 hospitalizations were observed.
To achieve effi ciency in results, it would be necessary that 250.6 potentially avoidable hospitalizations had not occurred, that is, 64.8% could have been prevented in these municipalities, in case they had adopted the benchmarks' practices.
Bermúdez-Tamayoa et al 3 (2004) correlated the hospitalizations due to CSPH in hospitals of Granada, Spain, with type of care, distance from hospital and sociodemographic factors and they found differences in the hospitalization rates due to CSPH associated with the organization characteristics of primary healthcare, size of municipality and distance from hospital. 3The ineffi ciency found in the present study was not subject to size or type of care, as the municipalities formed a homogeneous group that had the same size and type of primary healthcare (ESF).Distance from hospital was not analyzed.In the Spanish study, 4 this variable was related to the municipality's size and was an infl uent factor in the large municipalities, which were excluded from the present study.The hospitalization patterns can be infl uenced by other factors, such as the culture of use of services by the population, the admission policies in hospitals and the very quality of the provided services, which were also not evaluated.
The applied methodology enables the evaluation of avoidable costs, and it is possible to calculate the public expenditure on potentially avoidable hospitalizations in municipalities and estimate the wasted expenditure in Santa Catarina due to lack of effi ciency in primary healthcare.

Figure 1 .
Figure 1.Theoretical model of effi ciency in the production of services and results of actions related to systemic arterial hypertension (SAH) in primary healthcare.Santa Catarina, Southern Brazil, 2007.

Table 1 .
Benchmark reference municipalities in the production of assistance services to systemic arterial hypertension performed by the Family Health Strategy, their inputs and products.Santa Catarina, Southern Brazil, 2007.

Table 2 .
Effi ciency score, observed services, defi cit and effi cient production goals of services in systemic arterial hypertension for each ineffi cient municipality.Santa Catarina, Southern Brazil, 2007.

Table 3 .
Reference Municipalities for production of primary healthcare results related to systemic arterial hypertension and their inputs and products.Santa Catarina, Southern Brazil, 2007.

Table 4 .
Ineffi ciency in the avoided hospitalizations rate, goal of reduction in cardiovascular outcomes, observed outcomes and defi cit in protection to outcomes related to the control of systemic arterial hypertension in primary healthcare.Santa Catarina, Southern Brazil, 2007.

Table 5 .
Association between effi ciency in service production and in impact production related to systemic arterial hypertension and performed by the Family Health Strategy in municipalities located in Santa Catarina.Santa Catarina, Southern Brazil, 2007.