Let me Google that for you: a time series analysis of seasonality in internet search trends for terms related to foot and ankle pain

Abstract

Background: The analysis of internet search traffic may present the opportunity to gain insights into general trends and patterns in information seeking behaviour related to medical conditions at a population level. For prevalent and widespread problems such as foot and ankle pain, this information has the potential to improve our understanding of seasonality and trends within these conditions and their treatments, and may act as a useful proxy for their true incidence/prevalence characteristics. This study aimed to explore seasonal effects, general trends and relative popularity of internet search terms related to foot and ankle pain over the past decade.

Methods: We used the Google Trends tool to obtain relative search engine traffic for terms relating to foot and ankle pain and common treatments from Google search and affiliated pages for major northern and southern hemisphere English speaking nations. Analysis of overall trends and seasonality including summer/winter differences was carried out on these terms.

Results: Searches relating to general foot pain were on average 3.4 times more common than those relating to ankle pain, and twice as common as searches relating to heel pain. Distinct seasonal effects were seen in the northern hemisphere, with large increases in search volumes in the summer months compared to winter for foot (p = 0.004, 95 % CI [22.2-32.1]), ankle (p = 0.0078, 95 % CI [20.9-35.5]), and heel pain (p = 0.004, 95 % CI [29.1-45.6]). These seasonal effects were reflected by data from Australia, with the exception of ankle pain. Annual seasonal effects for treatment options were limited to terms related to foot surgery and ankle orthoses (p = 0.031, 95 % CI [3.5-20.9]; p = 0.004, 95 % CI [7.6-25.2] respectively), again increasing in the summer months.

Conclusions: A number of general trends and annual seasonal effects were found in time series internet search data for terms relating to foot and ankle pain. This data may provide insights into these conditions at population levels.

Keywords: Foot pain; Google Trends; ankle pain; ankle sprain; foot orthotics; insoles; plantar faciitis.

Fig. 1

Relative search volume of foot and ankle pain related terms. Shaded lines are weekly data; bold lines are a 5 week moving average. Note the reversal of minima/maxima in Australia (southern hemisphere). NH: northern hemisphere; AUS: Australia

Fig. 2

Local regression based decomposition of time series for pain terms. From left to right, these present results for FOOT PAIN, ANKLE PAIN, and HEEL PAIN. The top row represents northern hemisphere data, and the bottom data for Australia. Periodograms are included as the lowest subplot for each term/region

Fig. 3

Relative search volume of foot and ankle pain related terms. Shaded lines are weekly data; bold lines are a 5 week moving average. NH: northern hemisphere; AUS: Australia

Fig. 4

Local regression based decomposition of time series for pain terms. From left to right, these present results for PLANTAR FACIITIS and ANKLE SPRAIN. The top row represents northern hemisphere data, and the bottom data for Australia. Periodograms are included as the lowest subplot for each term/region

Fig. 5

Relative search volume of foot and ankle pain related terms. Shaded lines are weekly data; bold lines are a 5 week moving average. NH: northern hemisphere; AUS: Australia

Fig. 6

Local regression based decomposition of time series for pain terms. From left to right, these present results for FOOT ORTHOTIC, INSOLE, and FOOT SURGERY. The top row represents northern hemisphere data, and, where available, the bottom data for Australia. Periodograms are included as the lowest subplot for each term/region

Fig. 7

Relative search volume of foot and ankle pain related terms. Shaded lines are weekly data; bold lines are a 5 week moving average

Fig. 8

Local regression based decomposition of time series for pain terms. From left to right, these present results for ANKLE ORTHOSES, ANKLE EXERCISES, and ANKLE SURGERY in the northern hemisphere. Periodograms are included as the lowest subplot for each term