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PubMed2002

The score for allergic rhinitis (SFAR): a simple and valid assessment method in population studies.

BACKGROUND: No validated assessment of allergic rhinitis (AR) is presently available that can be used in population studies in the absence of medical diagnosis and of objective measurements of allergy. To compensate for this lack, a quantitative Score For Allergic Rhinitis (SFAR) ranging between 0 and 16 has been developed by experts. METHODS: The SFAR, encompassing eight features of AR, was validated in three different ways: 1) among 269 outpatients taking the specialist's diagnosis of AR and skin prick tests (SPT) positivity as a gold standard (diagnosis validation); 2) using psychometric methods (internal validation); and 3) in a random population-based sample of 3001 individuals by telephone interview (population acceptability). RESULTS: A SFAR value > or = 7 allowed satisfactory discrimination between the outpatients with AR from those without (sensitivity = 74% [95% confidence interval CI: 0.69,0.79], specificity = 83% [0.79, 0.87], positive predictive value = 84% [0.80, 0.88], negative predictive value = 74% [0.69, 0.79] and Youden's index = 0.57, respectively). Internal consistency of the score was also high (among others, Cronbach's alpha coefficient = 0.79). On average, it took only 3 min for the individuals interviewed on the phone to complete the questionnaire, the questions of which were well understood. Among these subjects, the prevalence of AR was 21% [95% CI: 19.5%, 22.5%], which is comparable to other determinations in France. CONCLUSIONS: The newly a priori proposed Score For Allergic Rhinitis (SFAR) is easy to use and can be useful to estimate prevalence and to study causation of AR in population settings.

Adolescent↗

PubMed1997

Development of two instruments examining stress and adjustment in children with cancer.

The childhood cancer literature provides limited understanding of the school-age child's perception of cancer stressors and factors that contribute to adjustment in the midst of these stressors. This study evaluated the reliability and validity of two questionnaires: the Childhood Cancer Stressors Inventory (CCSI) and the Children's Adjustment to Cancer Index (CACI). The following steps were involved in the instrument development process: item development, face and content validation, internal consistency reliability, and construct validity. Questions for both instruments were developed from the literature and experience of the principal investigator. A panel of five expert pediatric oncology nurses was asked to evaluate the content validity of both instruments. All the experts rated every item a 4-5 using the content validity index, indicating that each item measured the concept addressed by the scale. Seventy-five children with cancer were asked to complete the two questionnaires and parents completed a demographic data sheet that included eight questions about the child's school attendance, performance, number of friends, and activities. Children were 7 to 13 years of age; 64% were diagnosed with a leukemia/ lymphoma, and 36% had a solid tumor. Internal coefficient reliability for the total CCSI was .82, and .91 for the CACI. The CCSI correlated negatively with the adjustment scale (r = -.63, P = 000). The number of days missed from school correlated positively with the CCSI and negatively with the CACI. Children who missed more school perceived more cancer stressors and had a lower adjustment rating. Children with lower adjustment ratings on the CACI also had fewer friends (t = 3.4(72), P = .001). Scores on both instruments demonstrated expected relationships with measures hypothesized to covary with the dimensions assessed by the new instruments. Adjustment issues for children with cancer have been difficult to assess because of the lack of appropriate instruments. These study findings indicate that the two new instruments can help to measure the child's perceptions of the cancer experience.

Adaptation, Psychological↗

PubMed2004

Consensus kNN QSAR: a versatile method for predicting the estrogenic activity of organic compounds in silico. A comparative study with five estrogen receptors and a large, diverse set of ligands.

Quantitative structure-activity relationships (QSARs) have proved increasingly useful for predicting the biological activities of molecules (e.g., their binding affinities to different receptors) and can be used in environmental chemistry as a preliminary tool for screening the activities of untested molecules, producing valuable information on which compounds should be tested more thoroughly with experimental affinity assays or in animals. The predictive ability of the consensus kNN QSAR method is corroborated here using a diverse set of 245 compounds, which have been assayed for their relative binding affinities to the estrogen receptor of four species: human (ER alpha and ER beta), calf, mouse, and rat. Leave-one-out cross-validation (LOO-CV) and gamma-randomization tests were applied to the QSAR models for internal validation, and separate training and test sets were used for external validation. The internal predictive abilities of the consensus models for all five data sets were convincing, with cross-validated correlation coefficients (LOO-CV q2 values) varying from 0.69 (human ER beta data) to 0.79 (human ER alpha data). The external predictive abilities were also encouraging, as the predictive r2 scores (pr-r2 values) varied from 0.62 (human ER beta data) to 0.77 (calf and mouse data). The results indicate that consensus kNN QSAR is a feasible method for rapid screening of the estrogenic activity of organic compounds.

Animals↗

PubMed1985

Epidemiologic studies of organic micropollutants in drinking water.

Epidemiologic studies have been conducted in order to make a quantitative statement about associations between drinking water contaminants and disease. The basic measures of the association are a rate ratio or relative risk and rate difference or attributable risk. The appropriateness of this measure is dependent on components of study design, data collection, and the analysis of epidemiologic data, and these must be evaluated for each study to determine precision (lack of random error) and validity (lack of systematic error). Internal validity includes considerations for preventing selection bias, minimizing observation bias, and assessing, preventing, and controlling confounding bias within a particular study. No single epidemiologic study is likely to provide a definitive answer, and the results of epidemiologic studies must be interpreted in the context of other scientific information. Epidemiologic studies of organic micropollutants in drinking water have been reviewed and are summarized based on these considerations.

Chlorine↗

PubMed2001

Measuring qualitative aspects of preschool boys' noncompliance: the Response Style Questionnaire (RSQ).

Child noncompliance is a core maladjustment factor in current clinical models of aggression and antisocial development. However, little is known about the relations among qualitative aspects of child noncompliance and aggressive maladjustment. The authors developed the Response Style Questionnaire, an instrument designed to measure the multidimensional qualities of child noncompliance, and tested its validity and reliability. Tests of internal validity provided a five-factor solution, featuring distinctions in noncompliance quality between and among skilled noncompliance (verbally skilled and emotionally regulated) and unskilled noncompliance (overt/confrontational, covert/sneaky, and emotionally labile). Theory-driven tests of external validity using peer-adjustment variables as criteria provided discriminant prediction (a) among qualitatively distinct aspects of noncompliance and (b) between noncompliance qualities and rate. Discussion focuses on a modified view of the nature and role of noncompliance in aggressive and antisocial development.

Aggression↗

PubMed1977

Crucial role of the postnatal maternal environment in the expression of prenatal stress effects in the male rats.

Methodological and conceptual problems common in prenatal stress experiments were analyzed, and an experiment incorporating solutions to those problems were designed and executed. Rats were prenatally stressed or served as controls and then were cross-fostered within or between treatment groups. In adulthood, one male from each litter was tested over 20 trials in an open-field box and then tested over 20 successive discrimination reversals in a T-maze. A T-factor analysis was performed on each of the two sets of observations, and factors scores were subjected to elevational analyses. Major hypotheses generated from the results are the following: (a) Male rats subjected to prenatal stress acquire emotional reactivity levels in adulthood that are either elevated or reduced depending on the postnatal maternal environment. (b) Male rats subjected to prenatal stress acquire reversal learning sets in adulthood with a rapidity that parallels and indeed is produced by the pattern of emotional reactivity reflected in the above a and as mediated by cognitive processes. (c) T-factor analysis of trials is required in order to avoid construct validity problems as well as internal validity problems, both brought about by the confounding of trial variables, and in addition, it may generate valuable hypotheses giving further meaning to the dependent variables under observation.

Animals↗

PubMed2003

Validity of a population-based cancer register in Sweden--an assessment of data reproducibility in the South-East Region Prostate Cancer Register.

BACKGROUND: With a population-based setting, high coverage and accurately recorded data, the validity of a register is guaranteed. The South-East Region Prostate Cancer relies on the National Cancer Register as a basic source of data, thereby ensuring a high coverage of the corresponding geographic area. To assess the reproducibility of the data recorded a random sample of the cases were reviewed a second time and compared to the original recording. MATERIAL AND METHODS: The South-East Region Prostate Cancer Register was started in 1987. In addition to the basic data acquired from the Swedish National Register, it also includes tumour stage, grade, treatment and, since 1992, PSA. In the first stage of quality assessment 10 cases for each of the years 1987-1996 from Linköping University Hospital were randomly selected for two independent recodings according to the same protocol as the original registration. In the second step 10 cases each for the same years from the remaining 8 hospitals in the region were selected for a single recoding. RESULTS: No systematic deviations were seen between the two independent recodings from Linköping, a single recoding was therefore considered sufficient for assessing the reproducibility of the data from the remaining hospitals in the region. The Kappa values for agreement between the original registration and the single recoding ranged from 0.589 to 0.869. CONCLUSION: The population-based setting and high coverage guarantees the external validity of the register. The internal validity is ensured by the high reproducibility shown in the present study.

Humans↗

PubMed2005

Predicting outcome after traumatic brain injury: development and validation of a prognostic score based on admission characteristics.

The early prediction of outcome after traumatic brain injury (TBI) is important for several purposes, but no prognostic models have yet been developed with proven generalizability across different settings. The objective of this study was to develop and validate prognostic models that use information available at admission to estimate 6-month outcome after severe or moderate TBI. To this end, this study evaluated mortality and unfavorable outcome, that is, death, and vegetative or severe disability on the Glasgow Outcome Scale (GOS), at 6 months post-injury. Prospectively collected data on 2269 patients from two multi-center clinical trials were used to develop prognostic models for each outcome with logistic regression analysis. We included seven predictive characteristics-age, motor score, pupillary reactivity, hypoxia, hypotension, computed tomography classification, and traumatic subarachnoid hemorrhage. The models were validated internally with bootstrapping techniques. External validity was determined in prospectively collected data from two relatively unselected surveys in Europe (n = 796) and in North America (n = 746). We evaluated the discriminative ability, that is, the ability to distinguish patients with different outcomes, with the area under the receiver operating characteristic curve (AUC). Further, we determined calibration, that is, agreement between predicted and observed outcome, with the Hosmer-Lemeshow goodness-of-fit test. The models discriminated well in the development population (AUC 0.78-0.80). External validity was even better (AUC 0.83-0.89). Calibration was less satisfactory, with poor external validity in the North American survey (p < 0.001). Especially, observed risks were higher than predicted for poor prognosis patients. A score chart was derived from the regression models to facilitate clinical application. Relatively simple prognostic models using baseline characteristics can accurately predict 6-month outcome in patients with severe or moderate TBI. The high discriminative ability indicates the potential of this model for classifying patients according to prognostic risk.

Adolescent↗

PubMed2006

Validation of two automatic devices for self-measurement of blood pressure according to the International Protocol of the European Society of Hypertension: the Omron M6 (HEM-7001-E) and the Omron R7 (HEM 637-IT).

BACKGROUND: Two electronic devices for self-measurement of blood pressure - a brachial monitor, the Omron M6, and a wrist monitor, the Omron R7 - were evaluated in two separate studies according to the International Protocol of the European Society of Hypertension. DESIGN: The International Validation Protocol is divided into two phases: the first phase is performed on 15 selected participants (45 pairs of blood pressure measurements); if the device passes this phase, 18 supplementary participants are included (54 pairs of blood pressure measurements) making a total number of 33 participants (99 pairs of blood pressure measurements) on whom the final validation is performed. METHODS: The same methodology recommended by the European Society of Hypertension protocol was applied for both studies. In each study and for each participant, four blood pressure measurements were taken simultaneously by two trained observers using mercury sphygmomanometers alternately with three measurements taken by the tested device. The difference between the blood pressure value given by the device and that obtained by the two observers (mean of the two observers) was calculated for each measure. The 99 pairs of blood pressure differences were classified into three categories (<or=5, <or=10 and <or=15 mmHg). The number of differences in each category was compared with the number required by the International Protocol. An individual analysis was then done to determine the number of comparisons <or=5 mmHg for each participant. At least 22 of the 33 participants should have two of their three comparisons <or=5 mmHg. RESULTS: In both studies, the two tested devices passed the first and the second phases of the validation process. The average differences between the device and mercury sphygmomanometer readings were 0.8+/-2.7 and -1.9+/-3.3 mmHg for systolic and diastolic blood pressure, respectively, for the Omron M6 device, and 0.2+/-4.2 and 0.2+/-2.9 mmHg for systolic and diastolic blood pressure, respectively, for the Omron R7 device. For both devices, readings differing by less than 5, 10 and 15 mmHg for systolic and diastolic blood pressure values fulfill the recommendation criteria of the International Protocol as well as the individual analysis. CONCLUSIONS: The Omron M6 (HEM-7001-E) and the Omron R7 (HEM 637-IT) devices fulfilled the validation recommendations of the International Protocol.

Adult↗

PubMed2003

The nonarthritic hip score: reliable and validated.

The purpose of the current study was to assess the validity, internal consistency, and reproducibility of a short, self-administered hip score designed for use in younger patients with higher demands and expectations than older patients with degenerative joint disease. Validity and internal consistency was studied with 48 consecutive patients with a mean age of 33 years with intractable hip pain and normal plain radiographs. Reproducibility was assessed from data on an additional random sample of 17 patients with hip pain. The Pearson correlation coefficients were 0.82 and 0.59 between the nonarthritic hip score and the Harris hip score and Short Form-12, respectively showing validity. Cronbach's coefficient alpha measuring the internal consistency within each of the score's four domains ranged from 0.69 to 0.92. The test and retest reproducibility ranged from 0.87 to 0.95 for the four subsets and was 0.96 overall. This short, self-administered questionnaire regarding hip pain in young patients with increased activity demands and high treatment expectations is valid compared with previous measures of hip performance, is internally consistent, and is reproducible.

Adolescent↗

PubMed2006

The Acne Quality of Life Index (Acne-QOLI): development and validation of a brief instrument.

BACKGROUND: Acne affects many people and can be detrimental to affected patients' quality of life. Assessing the impact of acne on quality of life requires well-validated and reliable measures of acne-specific quality of life that are brief and easy to administer and interpret. OBJECTIVES: This paper reports on the development and validation of the Acne Quality of Life Index (Acne-QOLI) for use in clinical care, research, and product development. METHODS: Focus groups consisting of people from demographically different populations were conducted to identify the most relevant domains of functioning affected by acne; on the basis of these findings, candidate items were developed. An initial item pool of 58 items was included in a survey of 480 persons with mild to severe acne ranging in age from 12 to 62 years. Factor analysis and qualitative analysis were used to reduce the item pool to 21 items. The construct validity, concurrent validity, internal consistency, and test-retest reliability of the items were evaluated. RESULTS: The 21-item Acne-QOLI showed excellent face validity, content validity, concurrent validity, and construct validity. High internal consistency and test-retest reliability were also found. CONCLUSIONS: Quality of life is now recognized as an important outcome in medical care. The Acne-QOLI is a brief and easily administered and interpreted measure of acne-related quality of life that can be used in clinical care, research, and product development.

Acne Vulgaris↗

PubMed1999

External validation of IASP diagnostic criteria for Complex Regional Pain Syndrome and proposed research diagnostic criteria. International Association for the Study of Pain.

Recent work in our research consortium has raised internal validity concerns regarding the current IASP criteria for Complex Regional Pain Syndrome (CRPS), suggesting problems with inadequate sensitivity and specificity. The current study explored the external validity of these IASP criteria for CRPS. A standardized evaluation of signs and symptoms of CRPS was conducted by study physicians in 117 patients meeting IASP criteria for CRPS, and 43 patients experiencing neuropathic pain with established non-CRPS etiology (e.g. diabetic neuropathy, post-herpetic neuralgia). Multiple discriminant function analyses were used to test the ability of the IASP diagnostic criteria and decision rules, as well as proposed research modifications of these criteria, to discriminate between CRPS patients and those experiencing non-CRPS neuropathic pain. Current IASP criteria and decision rules (e.g. signs or symptoms of edema, or color changes or sweating changes satisfy criterion 3) discriminated significantly between groups (P < 0.001). However, although sensitivity was quite high (0.98), specificity was poor (0.36), and a positive diagnosis of CRPS was likely to be correct in as few as 40% of cases. Empirically-based research modifications to the criteria, which are more comprehensive and require presence of signs and symptoms, were also tested. These modified criteria were also able to discriminate significantly, between the CRPS and non-CRPS groups (P < 0.001). A decision rule, requiring at least two sign categories and four symptom categories to be positive optimized diagnostic efficiency, with a diagnosis of CRPS likely to be accurate in up to 84% of cases, and a diagnosis of non-CRPS neuropathic pain likely to be accurate in up to 88% of cases. These results indicate that the current IASP criteria for CRPS have inadequate specificity and are likely to lead to overdiagnosis. Proposed modifications to these criteria substantially improve their external validity and merit further evaluation.

Adult↗

PubMed2006

Reliability and validity of the International Cooperative Ataxia Rating Scale: a study in 156 spinocerebellar ataxia patients.

To evaluate the efficacy of treatments in spinocerebellar ataxias (SCAs), appropriate clinical scales are required. This study evaluated metric properties of the International Cooperative Ataxia Rating Scale (ICARS) in 156 SCA patients and 8 controls. ICARS was found to be a reliable scale satisfying accepted criteria for interrater reliability, test-retest reliability, and internal consistency. Although validity testing was limited, we found evidence of validity of ICARS when ataxia disease stages and Barthel index were used as external criteria. On the other hand, our study revealed two major problems associated with the use of ICARS. First, the redundant and overlapping nature of several items gave rise to a considerable number of contradictory ratings. Second, a factorial analysis showed that the rating results were determined by four different factors that did not coincide with the ICARS subscales, thus questioning the justification of ICARS subscore analysis in clinical trials.

Adolescent↗

PubMed1998

CEOP treatment results and validity of the International Prognostic Index in Chinese patients with aggressive non-Hodgkin's lymphoma.

From 1991 to 1997, we have treated 78 newly diagnosed patients with aggressive non-Hodgkin's lymphoma with a modified CHOP regimen in which epirubicin (60 mg/m2) was used in place of doxorubicin (50 mg/m2), i.e. CEOP (cyclophosphamide, epirubicin, vincristine and prednisolone). The median age was 41 years (range: 17 to 67). Sixty-four (82 per cent) had diffuse large cell (Working Formulation category G) histology. The median LDH level was 453 u/l. Thirty-three (42.3 per cent) and 45 (57.7 per cent) had stage I/II and stage III/IV disease, respectively. Fifty-five of 78 (71 per cent) CEOP-treated patients achieved CR, and the projected DFS and OS were both 65 per cent. In an earlier cohort of patients (from 1985-1991) treated with second or third-generation chemotherapy regimens (m-BACOD, MACOP-B, ProMACE-CytaBOM), CR was achieved in 95/123 (77 per cent) patients and the projected DFS and OS were 62 per cent and 55 per cent. There was no significant difference in the clinical characteristics, CR rates (p = 0.26), DFS (p = 0.38) or OS (p = 0.68) between patients who received CEOP or second/third-generation chemotherapy regimens. Of the patients treated with CEOP, 37.9 per cent, 28.8 per cent, 24.2 per cent and 9.1 per cent were in the age-adjusted International Index L, LI, HI and H risk groups, with CR rates of 82 per cent and 57 per cent in the L/LI and HI/H risk groups (p = 0.03). Moreover, patients in the L, LI and HI/H risk groups had significantly different projected DFS (87 per cent, 62 per cent and 39 per cent, p = 0.02) and OS (85 per cent, 80 per cent and 36 per cent, p = 0.006). In conclusion, CEOP is an effective regimen and the age-adjusted International Index is valid for Chinese patients with aggressive NHL.

Adolescent↗

PubMed2005

External cross-validation for unbiased evaluation of protein family detectors: application to allergens.

Key issues in protein science and computational biology are design and evaluation of algorithms aimed at detection of proteins that belong to a specific family, as defined by structural, evolutionary, or functional criteria. In this context, several validation techniques are often used to compare different parameter settings of the detector, and to subsequently select the setting that yields the smallest error rate estimate. A frequently overlooked problem associated with this approach is that this smallest error rate estimate may have a large optimistic bias. Based on computer simulations, we show that a detector's error rate estimate can be overly optimistic and propose a method to obtain unbiased performance estimates of a detector design procedure. The method is founded on an external 10-fold cross-validation (CV) loop that embeds an internal validation procedure used for parameter selection in detector design. The designed detector generated in each of the 10 iterations are evaluated on held-out examples exclusively available in the external CV iterations. Notably, the average of these 10 performance estimates is not associated with a final detector, but rather with the average performance of the design procedure used. We apply the external CV loop to the particular problem of detecting potentially allergenic proteins, using a previously reported design procedure. Unbiased performance estimates of the allergen detector design procedure are presented together with information about which algorithms and parameter settings that are most frequently selected.

Allergens↗

PubMed2002

Psychometric evaluation of the Body Change Inventory: an assessment instrument for adolescent boys and girls.

A new instrument, the Body Change Inventory, was developed to provide an assessment of body change strategies that are used by both adolescent girls and boys. The novel aspect of this instrument is that it evaluates strategies to increase body size and increase muscle size, as well strategies to decrease body size. Independent samples of adolescent girls and boys aged between 11 and 17 years (N=1732) participated in four studies. The revised instrument consisted of three body change scales-Strategies to Decrease Body Size, Strategies to Increase Body Size, and Strategies to Increase Muscle Size. The studies demonstrated content validity, construct validity, internal consistency, and concurrent and discriminant validity for the new scales. The new scales provide a valuable addition in the literature for assessing three global body change strategies among adolescent girls and boys. They are needed in order to examine further the normative development of different kinds of body change strategies and how these may lead to behavioural problems such as disordered eating, exercise dependence, and steroid use.

Journal Article↗

PubMed2001

Interpreting sexual behaviour data: validity issues in the multicentre study on factors determining the differential spread of HIV in four African cities.

BACKGROUND: The main conclusion of the multicentre study on factors determining the differential spread of HIV in four African cities was that differences in sexual behaviour could not, by themselves, explain the differences in HIV prevalence between the four cities. The present paper examines three potential sources of bias that could invalidate this conclusion: (1) changes in sexual behaviour since the start of the HIV epidemics; (2) bias due to the low response rates of men; and (3) bias in reported sexual behaviour. METHODS: To assess whether there have been any changes in sexual behaviour over time, selected parameters of sexual behaviour were compared between different age groups in the four cities. The maximum likely extent of bias due to non-participation of men in Yaoundé, Kisumu and Ndola was assessed with a simulation exercise, in which records of non-participants were replaced with records of 'low activity men' in Yaoundé and 'high activity men' in Kisumu and Ndola. To assess the validity of the sexual behaviour data, internal validity checks were carried out: comparing biological data on sexually transmitted infections with reports; comparing reports of spouses; and comparing numbers of sex partners reported by men and women. A fourth method consisted of comparing the findings of the multicentre study with an external source, Demographic and Health Surveys (DHS). RESULTS: There were differences in sexual behaviour between the younger and the older age groups in all four cities but there was no evidence of a shift towards safer sexual behaviour in the high HIV prevalence cities. After simulating results for male non-participants in Yaoundé, Kisumu and Ndola, the median lifetime number of sex partners was similar in Yaoundé, Kisumu and Ndola. By testing for various sexually transmitted infections among men and women aged 15-24 years who reported that they had never had sexual intercourse, we could establish that, in all four cities, at least 1-9% of men and 6-18% of women had misreported their sexual activity. The number of non-spousal partners in the past 12 months reported by men was two to three times higher than the number reported by women, as has been found in other studies. The most consistent differences between our survey and the DHS were found in the numbers of non-spousal partners in the past 12 months reported by never-married men and women. In all four cities, participants reported more non-spousal partners in the DHS than in our survey. CONCLUSIONS: In all four cities, we found evidence that men as well as women misreported their sexual behaviour, but overall it seems that under-reporting of sexual activity was not more common or more serious in the two high HIV prevalence cities than in the two low HIV prevalence cities. We believe that the main conclusions of the multicentre study still hold.

Adolescent↗

PubMed2005

Validity of a self-administered food frequency questionnaire (FFQ) and its generalizability to the estimation of dietary folate intake in Japan.

BACKGROUND: In an epidemiological study, it is essential to test the validity of the food frequency questionnaire (FFQ) for its ability to estimate dietary intake. The objectives of our study were to 1) validate a FFQ for estimating folate intake, and to identify the foods that contribute to inter-individual variation of folate intake in the Japanese population. METHODS: Validity of the FFQ was evaluated using 28-day weighed dietary records (DRs) as gold standard in the two groups independently. In the group for which the FFQ was developed, validity was evaluated by Spearman's correlation coefficients (CCs), and linear regression analysis was used to identify foods with large inter-individual variation. The cumulative mean intake of these foods was compared with total intake estimated by the DR. The external validity of the FFQ and intake from foods on the same list were evaluated in the other group to verify generalizability. Subjects were a subsample from the Japan Public Health Center-based prospective Study who volunteered to participate in the FFQ validation study. RESULTS: CCs for the internal validity of the FFQ were 0.49 for men and 0.29 and women, while CCs for external validity were 0.33 for men and 0.42 for women. CCs for cumulative folate intake from 33 foods selected by regression analysis were also applicable to an external population. CONCLUSION: Our FFQ was valid for and generalizable to the estimation of folate intake. Foods identified as predictors of inter-individual variation in folate intake were also generalizable in Japanese populations. The FFQ with 138 foods was valid for the estimation of folate intake, while that with 33 foods might be useful for estimating inter-individual variation and ranking of individual folate intake.

Diet↗