To measure foot-related health in podiatric patient populations (47).
Questions related to walking, foot health, foot pain, worry about feet, and impact of the foot on quality of life. Includes 7 subscales: walking, foot hygiene, nail care, foot pain, worry about feet, and impact on quality of life, with one question each and separate visual analog scale (VAS) for current foot status.
Number of items
6 questions and 1 VAS, for a total of 7 items.
Each dimension has 1 question related to it with 3 severity levels (no problems, some problems, and severe problems). 20-cm VAS delineated from 0–100.
Recall period for items
Examples of use
PHQ has been used in podiatric patient populations with various foot ailments and systemic diseases, such as rheumatoid arthritis and diabetes (47,48).
How to obtain
Available in the original article (47).
Method of administration
6 dimensions are summed per scoring guide to generate a single score ranging from 6–18.
Higher scores indicate more severe problems, and a higher VAS score indicates better foot health. Scoring is categorical, based on the level of severity (level 1 = no problems to level 3 = severe problems). The VAS is delineated from 0 (worst possible foot health) to 100 (best possible foot health) for the response item “How are your feet today?” (47).
Training of the podiatric staff for the PHQ and clinical podiatric assessment is 2 hours (47).
Method of development
Consultation of podiatric managers and podiatric clinicians (47).
The survey developers validated the PHQ against the generic health status assessment of the EuroQol 5-Domain instrument (EQ-5D) and an objective clinical assessment in which a podiatrist objectively scored the patient's foot health from 1 (no foot problems) to 5 (severe foot problems) (47). Comparing the PHQ to the clinical podiatric assessment, the Goodman-Kruskal lambda for the 2,038 patients for each dimension was: walking 0.15, hygiene –0.09, nail care –0.24, foot pain 0.41, worry/ concern for feet 0.30, and impact on quality of life 0.31. The PHQ was noted to be more robust in detecting foot-related health than the EQ-5D when it was compared to the clinical podiatric assessment (the subscale Goodman-Kruskal lambda ranged from 0.13–0.02) (47). Goodman-Kruskal lambda is a measure of the proportional ability of predicting the outcome for 1 categorical variable based on a second categorical variable. For construct validity, the PHQ subscales were correlated to the EQ-5D components ranging from 0.58–0.14 using Kendal correlation coefficients, and the PHQvas and EQ-5Dvas had a 0.40 Kendal correlation coefficient (47). These values suggest a low to moderate correlation, suggesting that the PHQ and EQ-5D detect different aspects of health.
Ability to detect change
In an independent study, Farndon et al used the PHQ to determine changes in foot status over a 2-week period after a podiatric intervention of 1,047 patients in 8 podiatric clinics (48). In 2 weeks, they noted a significant (P < 0.001) change in the PHQ dimension scores and the PHQvas for their patients. The PHQ of the 6 dimensions decreased by 0.5 (95% confidence interval [95% CI] 0.4–0.7). The PHQvas decreased by 0.7 (95% CI 0.6–0.9) using the PHQvas on a 0–10 scale (no pain to worse pain). While they initially used a clinical assessment to validate their PQH and PHQvas scores, in the followup PQH assessment, there was no followup clinical assessment to assess the validity of the change in scores. Therefore, the minimum detectable difference and minimum clinically important difference are both unknown.Critical Appraisal of Overall Value to the Rheumatology CommunityStrengths In terms of the number of survey questions, the PHQ is one of the shortest foot-related patient-reported outcome measures, which can limit the participant burden.Caveats and cautions The PHQ is a 1 question per domain measurement of foot health. This allows for patients and survey participants to quickly take the questionnaire; however, this may also increase measurement error because there is no means of ensuring the question was understood or was a representative answer of the impact of foot health on the patient's quality of life (44).Clinical usability Without known minimum detectable difference and minimum clinically important difference, the clinical utility of this survey is limited. Further, there are no questions regarding foot function, orthotics, and shoewear, all of which are important features of podiatric treatment and evaluation.Research usability Perhaps due to the sparseness of this survey with regard to the number and type of questions, this survey is not commonly used in research settings.