Study design, setting and participants
This was a prospective cohort study that assessed psychological status over time, before and after a general checkup, using a self-administered survey. The study was conducted at two facilities—a family physician teaching clinic responsible for primary care and a family physician teaching hospital with a 150-bed inpatient facility—in Kita-ku, Tokyo, a district with a large population of elderly residents approximately 15 km north of central Tokyo. Health checkups were conducted intensively between June and October 2011, and self-administered questionnaire assessments were conducted at three time points: before and after the explanation of the checkup results, and one month after the checkup. Instead of an intervention study, the observational study design was chosen because it may be ethically difficult to allocate “no notification” and/or “no disclosure” to participants, and this study focused on the psychological impact from the participants’ perspective.
The system of general health checkups for screening lifestyle-related diseases in Japan, called “specific health checkup”, is as follows: All adults aged 40 years or older who are covered by public health insurance are sent a voucher from the government office of their resident district to receive the health checkups for lifestyle-related diseases, and individuals are to undergo the checkup at a specified medical institution within their district. When individuals visit a medical institution for consultation in this district, they are eligible to receive blood pressure measurement, blood tests, chest X-ray, electrocardiogram, and urine test, free of charge. For the blood test results, values that deviate from pre-determined standard values are automatically identified by a computer, and are output and printed on the results sheet. The general checkup results are explained and guidance is given to the participants by the physician based on the results sheet at the institution where the participants received the general checkup.
Study participants comprised adults aged 40 years or older, but less than 75 years, who received this health checkup between June and October 2011 at one of the two specified facilities, and who did not regularly visit a medical institution and agreed to participate in the study. Those who had difficulty filling out the questionnaire due to reduced visual acuity and those who had been diagnosed with dementia were excluded. The target lifestyle-related diseases in this study were diabetes, dyslipidemia, hypertension, and hyperuricemia.
This study was approved by the Ethics Committee of Ouji Coop Hospital (approval number 41). A bulletin was posted in front of the medical room to provide information about the study, and informed consent was obtained verbally from all participants. The participant selection process is illustrated in Figure 1.
Measurement variables and evaluation process
The anxiety state of the patient was evaluated using a self-administered questionnaire, the State–Trait Anxiety Inventory (STAI), before the physicians explained the general checkup results. Detailed information about STAI is described in the Instruments section. The participant’s lifestyle habits were assessed using a self-administered questionnaire by determining the stages of behavioral change described by Prochaska [10]. Patients were classified into one of five stages: pre-contemplation, contemplation, preparation, action, or maintenance [11,12]. The stages of behavioral change are assessed for diet, exercise, drinking, smoking, and seeking medical care and are compared before and one month after of the general checkup. We developed a questionnaire that asks participants about their behavioral stages for each of diet, exercise, drinking, smoking, and seeking medical care [13]. Each stage was scored on a scale from 4 to 0 and compared before and one month after the general checkup. If participants’ answer was “Precontemplation stage”, it was scored as 4. The rest of the stages were scored as follows: “Contemplation stage” as 3, “Preparation stage” as 2, “Action stage” as 1, and “Maintenance stage” as 0.
The questions were as follows:
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Diet: What do you think about improving your diet behavior?
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Exercise: What do you think about exercising for 30 min at least twice a week?
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Seeking medical care: What do you think about seeing a doctor regularly?
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Drinking: Appropriate drinking is up to 20 g of alcohol (180 ml of Japanese sake) each day, and the general recommendation is to abstain from drinking alcohol twice a week. What do you think about this habit?
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Smoking: What do you think about quitting smoking?
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For questions about drinking and smoking, since the question is concerned about addictive behavior, we excluded the stage of maintenance according to its definition that the stage extends from six months to an indeterminate period.
Participant’s characteristics (gender, age), screening for depression (two questions) were also assessed using an additional questionnaire.
Immediately after a physician explained the participant’s results from the health checkups, his/her anxiety state was evaluated again using STAI. An additional questionnaire was also administered to ask whether the physician had told the participants of any abnormal results or had diagnosed a lifestyle-related disease, and if so, what the diagnosis was.
The purpose of this study was masked from the physicians who explained the results of general checkups to participants, and they were given instructions to approach the participants as they normally would. The automatic assessment criteria for abnormal levels were determined according to the International Diabetes Federation (IDF) standard from 2005 and Third Report of the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATPIII) standards [14], and were as follows: ≥130/85 mmHg for hypertension, ≥150 mg/dL for triglycerides, <40 mg/dL (men) and <50 mg/dL (women) for HDL-c, and ≥100 mg/dL for plasma glucose. The abnormal level for uric acid for both men and women was >7.0 mg/dL, which is the upper normal limit commonly used in Japan [15]. HbA1c was also considered as a marker for diabetes, and HbA1c ≥6.5% (NGSP) was determined as abnormal [16,17]. In addition, considering the possibility that the level of abnormality in markers is likely to have an effect on the physician’s explanation to a participant, we also conducted analysis for only those with mild abnormality (mild group) since the farther the result is from the reference value, the more confidently and assertively a physician would explain the result and diagnosis. Those with mild abnormality were not in the stage that would generally require immediate treatment at medical consultations in Japan, but had borderline high values that require attention according to NCEP-ATP III and AHA guidelines [11,18,19]. The following values were used as criteria to determine mild abnormalities: systolic blood pressure of 140–159 mm Hg and diastolic blood pressure of 90–99 mm Hg for hypertension, triglycerides of 150–199 mg/dL and LDL of 150–159 mg/dL for dyslipidemia, and HbA1c (NGSP) of 6.5–7.0% for diabetes [16,17]. In those who were pointed out to have a high marker for uric acid, patient recollections were usually concerned with hyperuricemia treatment that would usually apply to patients with a history of gout; therefore, uric acid levels were not used as a criterion of mild abnormality.
The collection staff monitored participants as they filled out the self-administered questionnaire before and after the general checkup, and the questionnaires were recovered from all participants in front of the medical room after the checkup. One month after the general checkup results were explained to a study participant at a physician’s consultation, a questionnaire was mailed to those who had abnormal levels in markers of lifestyle-related disease. The replies are sorted into those who were notified of abnormalities in markers or who were notified of a diagnosis of lifestyle-related disease. This questionnaire included STAI, as well as additional questions on stages of behavioral changes in diet, exercise, drinking, smoking, and seeking medical care, and whether or not their lifestyle habits had improved. Explanation to the participants was given as “the questionnaire is asking whether your lifestyle has changed after the health checkup and about anxiety change before and after the health checkup. The questionnaire strictly focuses on the health checkup, and answers would not affect any action resulting from your regular consultation.”
The questionnaire was filled out by the study participants and returned by mail. Self-administered questionnaires that contained blanks or were difficult to evaluate were treated as missing data and were excluded from the analysis.
In the present study, patients were directly asked whether they were notified of abnormalities by the physician, and whether the diagnosis was disclosed to them. The reason why the physicians were not surveyed about their decision for participants’ results was that conducting a survey for the physicians who explained the results of general checkup including abnormalities and disease disclosure would affect their clinical practice style during the study period, potentially creating a bias. As this study focuses on a natural process of doctor–patient interaction, the purpose of this study was obliged to be concealed to doctors. In addition, the purpose of the present study was not to investigate the intervention effect by disclosing the diagnosis to patients but to focus on the psychological impact of general checkup results on patients based on the patient’s perception. In addition, it may be ethically difficult to allocate “no notification” and/or “no disclosure” as physicians’ behavior to participants. Therefore, we considered that the impact of disease disclosure should be evaluated from the perspective of the patients first.
Instruments
STAI, developed in 1966 using Spielberger’s theory, is a 40-item questionnaire that measures both state anxiety and trait anxiety. State anxiety is an anxiety state induced in a short period of time by situations that are perceived as harmful. Trait anxiety is an anxiety state caused by one’s innate personality. In the present study, both state anxiety and trait anxiety were assessed by state-Trait Anxiety Inventory (Japanes version) [20,21] to determine whether the anxiety state was greatly affected by the patient’s innate personality or induced by purely being notified of a disease condition.
Size of study
In order to test the hypothesis that anxiety was induced by receiving notifications of an abnormality or disease at a general checkup, the number of samples required to conduct the study was determined in advance. Each question in STAI is rated on one of the following 4-point scales (listed in increasing point value): “very much so, moderately so, somewhat, not at all” or “almost never, sometimes, often, almost always”. Scores of 1–4 points are added, and the total scores range from 20 to 80. The total score is classified into the following five levels of anxiety: very high, high, normal, low, and very low. There are approximately 10 points between each of these levels. When the mean change in the STAI score upon receiving notification at the general checkup was assumed to be 5 points and standard deviation (SD) was assumed to be 15, the number of samples statistically required for the study became 190 for one group (α = 0.05, β = 0.10). In order to compare the groups of people whose anxiety was induced versus not induced, the number of samples required became 380. Therefore, the target sample number was set to approximately 400.
Analysis and statistical methods
The following two aspects were assessed for: 1) whether the participant’s anxiety scale STAI score is affected; and 2) whether there are behavioral changes in daily lifestyle.
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1)
Participants were divided into three groups: those not notified of any abnormalities in markers of lifestyle-related disease through automatic assessment (hereinafter “no abnormality group”), those notified of abnormalities and were told of the disease diagnosis by the physician (“disease disclosed group”), and those notified of abnormalities but were not told of the disease by the physician (“notified of abnormality/disease undisclosed group”). Whether or not the changes in state of anxiety are different between each of the two groups was determined using Student’s t test for parametric data and the Wilcoxon rank-sum test for nonparametric data. Bonferroni correction for multiple comparisons was applied in this case. The Shapiro–Wilk test was used to determine whether the data were parametric or nonparametric. As shown in Figure 1, those who responded that they were notified of abnormalities in diseases other than lifestyle-related diseases were excluded from the analysis. For changes in state of anxiety, in order to evaluate the independent impact of disease diagnosis disclosure, logistic regression analysis adjusting for gender, age, depressed mood, loss of interest, trait anxiety, diabetes, hyperlipidemia, hypertension, and hyperuricemia as covariates was conducted [22]. Logistic regression analysis was similarly conducted in a group of participants limited to those with mild abnormalities in lifestyle-related disease markers. The anxiety assessment scale STAI was used in the present study, and its results were classified into five levels with each level approximately ten points apart. A higher total score indicates higher anxiety, with the five levels having anxiety levels of very high, high, normal, low, and very low. In the logistic regression analysis, we constructed two models, one using the five levels that are approximately ten points apart in each level and another using half-levels that are approximately five points apart in each level as outcome development of clinically significant changes in state anxiety.
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2)
Changes in lifestyle habits one month after the explanation of general checkup results between the notified of abnormality/disease undisclosed group and disease disclosed group were compared using the Wilcoxon rank-sum test. In addition, Spearman’s correlation coefficients were used to elucidate the association between change of state anxiety before and just after the checkup, and changes of behavioral stages one month after the checkup.
All statistical analyses were performed using STATA/SE version 10.1. P < 0.05 was considered to be statistically significant [23].
