Vol. zyxwvutsrqpo 56, zyxwvutsrq No. 4, Summer 1996 205 Validity of a Self-reported Periodontal Disease Measure Kaumudi J. Joshipura, BDS, SD; Chester W. Douglass, DMD, PhD; Raul 1. Garcia, DMD, MMedSc; Richard Valachovic, DMD, MPH; Watter C. Willett,-MD, DrPH Abstract zyxwvutsrq 0b)ectives: The purpose of this study was to determine the validity of a self-reported periodontal disease measure for use in the Health Professionals Follow-up Study. Methods: Participating dentists responded to the question Wave you had periodontal disease with bone loss?” Radiographs obtained from 140 pamcipnts zyxwvutsrq were evaluated for bone loss at 32 posterior sites and zyxw used as the standard. A site was positive if it had bone loss >2 mm and/or complete loss of crestal lamina dura. To avoid falsely classij,ing participants as positive, three blinded examiners independently evaluated each participant’s radiographs.An a priori decision rule was used to classij, a participant positive if all examiners independently assessed the same two or more sites positive. Results: The validity of the self-reported measure was good among dentists, with positive and negative predictive values of 0.76 and 0.74, respectively.Among nondentists,the self-reported measure showed discriminatory power by confirming associations with known risk factors such as age and smoking. Conclusions: Dentists have a good perception of their periodontal status, and there is reasonableconsensus among dentists regarding the threshold for defining periodontal disease. Self-re- ported measures might have potential for use in studies of otherpopulationswith substantial cost reduction, and deserve further evaluation. [J Public Health Dent ?996;56(4):205- 121 Key Words: validify, periodontal disease, alveolar bone zyxwvut loss, radiographs,self-re- port. Self-reported periodontal measures rarely have zyxwvuts been used, as the general population is believed to be poorly in- formed about their periodontal status. Clinical or radiographic measures are likely to give better estimates of peri- odontal status. However, self-re- ported measures have great practical advantages in terms of cost, time, and convenience, and may be the only fea- sible measure obtainable from large study populations. A few studies have validated other self-reported oral health measures showing that people generally are well able to report their number of teeth (I), but have a low to moderate perception of other oral health measures (28). Only one study in the literature reported using a self- reported periodontal measure. How- ever, the validity of the measure was not assessed (9). This paper describes the validity of a self-reported measure of periodontal disease history among dentists partici- pating in the Health Professionals Fol- low-up Study (HPFS). This measure is being evaluated for use in studying the associations of periodontal disease with diet and systemic diseases in this population. It is reasonable to expect dentists to value and maintain good dental care, be well aware of theirden- tal condition, and thus be knowledge- able and able to report their periodon- tal status. Hence this initial validation study was limited to dentists because the validity is expected to be lower among other health professionals. The self-reported measure con- sisted of the response to a single ques- tion: ”Have you had periodontal d i s ease with bone loss?” Since almost all adults have experienced some amount of bone loss, a threshold is generally defined in order to have a measure with some discriminatory power; hence, mild disease usually is ignored z (10,111. There is no universally ac- cepted threshold for periodontal bone loss and no definition was provided in the questionnaire. The threshold was left to the judgment of each partici- pant. Since the self-reported measure was based on diagnoses by different dentists across the country, the valid- ity of this measure provides an esti- mate of the degree of consensus among dentists regarding the thresh- old for defining periodontal bone loss. Validation of this measure also pro- vides an estimate of the periodontal status of this population of US den- tists. We assessed the validity of this measure using radiographs as the standard because they provide a feasi- ble assessment of bone loss (12,131, and compare well with the hue bone loss status (14,151. We also examined the associations of the self-reported measure with known risk factors such as age and smoking to see if the meas- ure had discriminatory power among both dentists and nondentists in the HPFS. In addition, we compared the association between age and peri- ~ Send correspondence and reprint requests to Dr. Joshipura, Department of Oral Health Policy and Epidemiology, Harvard school of Dental Medicine, 188 Longwood Avenue, Boston, MA 02115. Internet: kaumudi.joshipura@channing.harvard.edu Dr. Douglass is with the Department of Oral Health Policy and Epidemiology, Harvard school of Dental Medicine, and the Department of Epidemiology, Harvard School of Public Health. Dr. Garcia is with the VA Dental LongitudinalStudy, Boston VA OutpatientClinic; the Department of Oral Pathology and Medidne, Tufts University School of Dental Medicine; and the Department of Oral Medicine and Diagnostic Sciences, Harvard School of Dental Medicine. Dr. Valachovic is also with the Department of Oral Medicine and Diagnostic sciences. Df. Willett is with the Department of Epidemiology, Harvard School of Public Health; with the Department of Nutrition, Hanard School of Public Health; and with the Oanning Laboratory, Harvard Medical School, tleparhnent of Medicine, Brigham and Women’s Hospital. This study was supported by CA55075, HUM, and by the Health SeMces Research and Development Service, US Department of Veterans Affairs. Dr. Joshipura was supported by the Dentist Scientist Award. Dr. Garaa is also a Career Development Awardee of the VA HSR&D Service. This paper was presmted at the IADR meeting in Singapore on July 1,1995. Manusaipt received: 6/15/95; returned to authors for revision: 9/21 /95; accept4 for publication: 12/22/95.