**3. Results**

For the three manual therapy professions combined, an estimated 1,322,370 (13.2%) fewer services were provided during the first half of 2020. The estimated reduction in total cost of services provided amounted to AUD 83,972,816 (11.5%). The combined estimated relative reduction in quarterly number and total cost of services provided was greater in Q2 (21.7% and 16.6%, respectively) than in Q1 (5.7% and 6.8%, respectively).

During the first half of 2020, the estimated relative reduction in number of services provided was considerably larger in physiotherapy (20.6%) and osteopathy (12.7%) than in chiropractic (5.2%). Figure 1 shows a time series plot of observed values and point forecast estimates with 95% prediction intervals of the quarterly number of services provided by each manual therapy profession from 2015 to 2020 Q2. Similarly, the estimated relative reduction in the quarterly total cost of services provided was considerably larger in physiotherapy (17.0%) and osteopathy (13.1%) than in chiropractic (4.7%). Figure 2 shows a time series plot of observed values and point forecast estimates with 95% prediction intervals of the quarterly total cost of services provided by each manual therapy profession from 2015 to 2020 Q2. Table 1 provides an overview of observed values, point forecast estimates, mean absolute error, and mean absolute percentage error of the quarterly number and total cost of services provided by each manual therapy profession during 2020 Q1 and Q2.

**Figure 1.** Time series plot of observed values and point forecast estimates with 95% prediction intervals of the quarterly number of services provided by each manual therapy profession from 2015 to 2020 Q2.

**Figure 2.** Time series plot of observed values and point forecast estimates with 95% prediction intervals of the quarterly total cost of services provided by each manual therapy profession from 2015 to 2020 Q2.

**Table 1.** Observed values, forecast point estimates, mean errors, and mean percentage errors of the quarterly number and total cost of services provided by each manual therapy profession in Australia during 2020 Q1 and Q2.


The estimated relative reduction in number and cost of services provided during the first half of 2020 varied by Australian state and territory. The estimated relative reduction in number of services provided was largest in New South Wales (17.5%), followed by Australian Capital Territory (16.3%), Victoria (16.2%), Tasmania (15.0%), South Australia (10.3%), Queensland (8.7%), Western Australia (7.9%), and Northern Territory (0.3%). Similarly, the estimated relative reduction in total cost of services provided was largest in New South Wales (15.6%) and Australian Capital Territory (15.6%), followed by Victoria (15.0%), Tasmania (11.2%), South Australia (9.3%), Western Australia (7.9%), Queensland (6.4%), and Northern Territory (0.9%). Figures 3 and 4 are heatmaps depicting the estimated mean percentage error in number and total cost of services, respectively, provided by the three manual therapy professions during the first half of 2020 across Australian states and territories.

**Figure 3.** Heatmap of the estimated mean percentage error in number of services provided by each manual therapy profession during the first half of 2020 across Australian states and territories.

**Figure 4.** Heatmap of the estimated mean percentage error in total cost of services provided by each manual therapy profession during the first half of 2020 across Australian states and territories.

Because the number of individuals with general treatment cover and the number of manual therapy providers varied from quarter to quarter, supplementary analyses were conducted using secondary outcome variables and are presented in the Supplementary Materials (Sections B and C, respectively). These supplementary analyses generated similar estimates of the percentage change in manual therapy service utilization.

#### **4. Discussion**

This is the first study to estimate the impact of the COVID-19 pandemic on manual therapy service utilization. During the first half of 2020, the COVID-19 pandemic coincided with approximately 1.3 million fewer chiropractic, osteopathy, and physiotherapy services provided within the Australian private healthcare system. The associated loss of revenue was estimated to be AUD 84 million. Physiotherapy incurred the largest relative reduction in service provision and revenue, while chiropractic was found to be the least impacted of the three manual therapy professions. Geographically, the largest relative reductions in manual therapy service utilization were observed in the south-eastern corner of mainland Australia (i.e., New South Wales, Australian Capital Territory, and Victoria).

Our findings show that the COVID-19 pandemic has had a profound impact on manual therapy service utilization in Australia. It is not unexpected to observe disruption of health services during a global pandemic. While much of the initial disruption of health services has been characterized by the surge in demand for front-line care of COVID-19 patients, there has also been a concomitant reduction in or discontinuation of prevention and rehabilitation services for noncommunicable diseases. For instance, the World Health Organization reported that more than half of the countries surveyed had partially or completely disrupted services for the treatment or clinical management of hypertension, diabetes and diabetes-related complications, cancer, and cardiovascular emergencies [18]. A similar situation exists in Australia, where there have been marked reductions in a wide range of health services, including breast and prostate cancer screenings [19,20], pediatric orthopedic hospital services [21], trauma care in Emergency Departments [22,23], and initiation of cardiopulmonary resuscitation by Emergency Medical Services in public areas [24]. It is important to note that our findings encompass only the initial disruption caused by the COVID-19 pandemic. It remains to be determined whether the decline in manual therapy service utilization persists beyond the first half of 2020, whether manual therapy service utilization returns to pre-pandemic levels after the virus has been eliminated, and whether economic factors such as sustained or transient changes in disposable income, uptake of private health insurance, and cost of services have any lasting effects on healthcare-seeking behavior and manual therapy service utilization. Future studies are encouraged to explore these unresolved questions.

The magnitude of the decline in manual therapy service utilization during the COVID-19 pandemic was not uniform across the three professions, with physiotherapy and chiropractic experiencing the largest and smallest relative reductions, respectively. The exact reason for this difference is unclear, but it may be related to differences in revenue streams (e.g., proportion derived from private health insurance) and patient characteristics (e.g., level of disposable income) across the three professions [12]. For instance, as the COVID-19 pandemic has unfolded and loss of income became more prevalent in the population, perhaps Australians have forfeited their private health insurance with general treatment cover as a cost-saving measure. While this explanation may sound reasonable given the circumstances, it does not explain why there was a larger decline in physiotherapy service utilization relative to chiropractic and osteopathy. Nor does it explain the fact that the results from our supplementary analyses of service utilization per 100,000 insured persons were very similar to our main findings, which suggests that any changes in the number of insured persons are unlikely to explain the observed differences. An alternative explanation may be differences in case-mix across the three manual therapy professions. Although this explanation is not supported by the scope of practice of the three professions, which all state that they diagnose and treat musculoskeletal conditions, industry reports indicate that physiotherapy provides more specialized services (e.g., neurological rehabilitation, geriatric services, and sports injury prevention and rehabilitation) than osteopathy and chiropractic [25,26]. Thus, it is conceivable that public health orders and social restrictions related to the COVID-19 pandemic (e.g., stay-at-home directives, limited access to aged care facilities, and shutdown of community sport activities) may have resulted in a marked reduction in utilization of specialist physiotherapy services. Although this may explain the larger relative reduction in physiotherapy service utilization (20.6%), it does not adequately explain the differences in relative reduction in services

between osteopathy (12.7%) and chiropractic (5.2%). Further research is needed to examine the factors influencing healthcare-seeking behavior and manual therapy service utilization during the COVID-19 pandemic and to elucidate the underlying reasons for the observed differences across the three manual therapy professions.

There are strengths and limitations of the present study. This research builds on our previous reports of manual therapy service utilization within the Australian private healthcare setting [11,12]. We added an inflation adjustment for all dollar values to remove the effect of inflation from our analyses. More importantly, we applied sophisticated analytical techniques to produce forecasts that account for both seasonal variation and long-term trends across professions and geographical regions (i.e., states and territories). In an attempt to account for changes in the number of providers and people with private health insurance, we provided supplementary analyses using secondary outcome variables (i.e., number and total cost of services provided per provider and per 100,000 persons with private health insurance). These supplementary analyses produced very similar estimates of the impact of the COVID-19 pandemic on manual therapy service utilization. Lastly, because our study was limited to private health insurance data, the estimates presented herein can only be generalized to services provided under private health insurance general treatment cover.
