Teleconsultations reduce greenhouse gas emissions

Abstract

Objectives

Health services contribute significantly to greenhouse gas emissions. New models of delivering care closer to patients have the potential to reduce travelling and associated emissions. We aimed to compare the emissions of patients attending a teleconsultation – an outpatient appointment using video-conferencing equipment – with those of patients attending a face-to-face appointment.

Methods

We estimated the total distances travelled and the direct and indirect greenhouse gas emissions for 20,824 teleconsultations performed between 2004 and 2011 in Alentejo, a Portuguese region. These were compared to the distances and emissions that would have resulted if teleconsultations were not available and patients had to attend face-to-face outpatient appointments. Estimates were calculated using survey data on mode of transport, and national aggregate data for car engine size and fuel. A sensitivity analysis using the lower and upper quartiles for survey distances was performed.

Results

Teleconsultations led to reductions in distances and emissions of 95%. 2,313,819 km of travelling and 455 tonnes of greenhouse gas emissions were avoided (22 kg of carbon dioxide equivalent per patient). The incorporation of modes of transport and car engine size and fuel in the analysis led to emission estimates which were 12% smaller than those assuming all patients used an average car.

Conclusions

The availability of remote care services can significantly reduce road travel and associated emissions. At a time when many countries are committed to reducing their carbon footprint, it is desirable to explore how these reductions could be incorporated into technology assessments and economic evaluations.

Keywords

carbon footprint remote consultation telemedicine

Introduction

Health services contribute significantly to greenhouse gas (GHG) emissions. In England, the National Health Service’s (NHS) overall carbon footprint stands at 20 million tonnes of carbon dioxide equivalent (tCO₂e, a universal unit of measurement that allows the global warming potential of different GHGs to be compared), or 30% of the public sector’s total.¹ In the USA, the health sector contributes 8% of total GHG emissions.² To help meet a national target of 80% reduction in emissions by 2050 (from 1990 levels), the English NHS has committed to a 10% reduction in its own emissions by 2015.

While the bulk of health care emissions are associated with procurement and use of energy (fossil fuels and electricity) in buildings, patient travel is the origin of significant emissions. In 2010, travelling accounted for 16% of GHG emissions attributable to the NHS, with journeys made by staff, patients and visitors representing 5% of all road transport emissions in England.³ In the USA, the providers organized in the National Association for Home Care and Hospice alone were responsible for nearly 5 billion miles in 2008, more than those driven by the United Parcel Service in the same year.⁴ Previous research has shown that reductions in travel emissions can be achieved through innovative ways of delivering health care services, in particular by bringing care closer to patients.^{5

–8} This is likely not only to reduce energy requirements for travel but also building energy use. Moreover, shorter distances can be more easily covered by walking or cycling, promoting health as well as further reducing the need for health care.⁹

Previous studies have explored the impact of remote care interventions on travel emissions. Masino et al.⁵ estimated the reduction in GHG emissions from 840 teleconsultations completed over a period of six months in Ontario, Canada and concluded emissions were cut by approximately 185 tCO₂e (220 kg CO₂e per patient). Lewis et al.⁶ studied the use of video-conferencing to assist multidisciplinary teams deliver cancer services in rural areas of west Wales and estimated emission reductions for 21 meetings in October 2006 (1696 kg of CO₂) and 30 meetings in October 2007 (2590 kg of CO₂), avoiding a total of 84 kg of CO₂ per meeting. Dorrian et al.⁷ investigated the use of head and neck cancer assessment teleconsultations for 42 patients from the Shetland Islands, Scotland. The authors estimated an average saving of 123 kg of CO₂ per patient. Finally, Bond et al.⁸ assessed the impact of mobile breast screening clinics with an estimated reduction between 233.8 and 234.6 tCO₂ (3.85–3.87 kg CO₂ per patient).

There are a number of limitations in previous research. All studies assume patients drive an average car with a specific fuel and engine size (or cars with an average emission). Second, patients may use other modes of transport besides cars. For example, emission coefficients for bus and coach travel are lower than for an average car. Third, there have been no studies including indirect GHG emissions. Direct emissions are those emitted at the point of use of a vehicle, while indirect emissions include those from production and distribution of fuels to their point of use (emissions from the production of vehicles or infrastructure are not considered). Finally, only Bond et al. have assessed impact over a long period of time.

In this study, we address these limitations by combining a number of data sources on modes of transport, engine size and fuel type, to estimate the impact of eight years of teleconsultations in Alentejo, a region in Portugal, on the distances travelled and associated direct and indirect GHG emissions.

Methods

Teleconsultations are real-time outpatient appointments using video-conferencing equipment to connect patients visiting their general practitioners to remotely located consultants. In Alentejo, they have been used since 1998 to help deal with a significant mismatch between the needs of a geographically dispersed population and a concentrated supply of specialized outpatient services. Local primary health care centres are free to choose whether they wish to use teleconsultations or not. The region covers a third of Portugal, yet it is home to only 5% of the population. The average alentejano is poorer, older and less educated than the average Portuguese. The region also has a poor public transportation network. All these factors create significant challenges for health care services seeking to ensure equity in access.

Sources of data

We conducted a survey of 100 teleconsultation patients and 100 face-to-face outpatients who had appointments in the second half of 2011 with consultants from the Hospital do Espírito Santo de Évora. Respondents were asked about distances travelled and modes of transport used. Patients who had had consultations in neurology, dermatology, physical and rehabilitation medicine, and general surgery were included. Lists of all patients who had an appointment were produced for each specialty and each pathway (i.e. teleconsultation or face-to-face). Each specialty/pathway combination was given a weighting factor according to the proportion of all appointments in the study population. The 100 patients were randomly selected from each pathway and within these specialties the number of patients reflected the weighting factors calculated above.

The survey was conducted in February 2012 by personnel from the hospital’s Patient Management Department, who regularly conduct patient satisfaction surveys. Patients were contacted by telephone. If a patient failed to answer the call, the next patient on the specific specialty/pathway list would be contacted. None of the patients who were successfully contacted declined to participate (Table 1).

Table 1.

Characteristics of the sample.

Characteristic	n
Sex
Male	40
Female	58
Missing	2
Total	100
Employment status
In paid work	31
Retired, unemployed	64
Student	4
Missing	1
Total	100
Annual income
<€7000	62
€7000–€15,000	30
€15,001–€30,000	5
€30,001–€60,000	1
Missing	2
Total	100
General health status
Very good	3
Good	30
Neither good nor bad	49
Bad	17
Very bad	1
Total	100
Level of education
No formal qualifications	10
Basic education	44
Secondary education	32
Higher education	6
Total	100
Medical specialty of appointment
Neurology	13
Dermatology	69
General surgery	12
Physical and rehabilitation medicine	6
Total	100
Satisfaction with appointment
Very satisfied	42
Somewhat satisfied	54
Indifferent	2
Somewhat dissatisfied	2
Very dissatisfied	–
Total	100

In addition to survey data, we analysed information on the referring and receiving health care units for all 20,824 teleconsultations performed in Alentejo from 2004 to 2011. Lastly, we used aggregate national data on the fuel distribution of vehicles in use and engine size for cars sold in Portugal.^10,11

Estimating emissions

We estimated the reduction in GHG emissions over eight years of teleconsultations in Alentejo. Google Maps™ was used to determine the actual travelling distances to face-to-face appointments if teleconsultations would not have been available. Because we had no information on patients’ places of residence, we assumed that patients travelled the same mean distances as those reported in the survey to get to their teleconsultation appointment in the primary care centre. We assumed that if teleconsultations had not been available, patients would have needed to travel a distance equal to the distance between the referring primary care centre and the hospital for a face-to-face appointment.

Second, we used survey responses of teleconsultation patients to determine the vehicle mix for patients travelling to teleconsultation appointments, and the responses of face-to-face patients to determine the vehicle mix for face-to-face appointments. We further sub-divided those travelling by car into six combinations of engine size and fuel, disregarding fuels other than petrol and diesel, as these were used by only 1% of all vehicles in use in Portugal (Table 2). There are no available data on engine size for vehicles in use in Portugal, so we used data on cars sold. Having established the vehicle mix for both pathways, we calculated the total distances travelled in each mode and each pathway. For teleconsultations, we first determined the number of patients using each mode and then multiplied these with mean distances reported in the survey. We conducted a sensitivity analysis using the lower and upper quartiles for distances reported in the survey (Table 3) to establish emission reductions in best- and worst-case scenarios. For face-to-face appointments, we determined the number of kilometres travelled in each mode by multiplying the total estimated distance (from Google Maps™) by the vehicle mix for face-to-face appointments.

Table 2.

Car engine size and fuel in Portugal.

Fuel	Size	%
Petrol	0–1500	50%
	1501–2000	3%
	>2000	1%
	Total	54%
Diesel	0–1750	28%
	1751–2000	14%
	>2000	4%
	Total	46%

Sources: INE¹⁰ and ACAP.¹¹

Table 3.

Self-reported one-way distances (km) by mode of transport: descriptive statistics.

Pathway	Mode	n	% n	Min	Max	Mean	σ	Q1	Q2	Q3	Sum	% Sum
Teleconsultation	Car/taxi	57	57%	0.5	60.0	9.0	11.5	2.0	5.0	12.0	513	87%
	Bus	2	2%	12.0	13.0	12.5	0.7	12.0	12.5	13.0	25	4%
	Ambulance	2	2%	2.0	6.0	4.0	2.8	2.0	4.0	6.0	8	1%
	Walk	39	39%	0.1	5.0	1.1	1.0	0.5	1.0	1.0	41	7%
	Total	100	100%	0.1	60.0	5.9	9.6	–	–	–	587	100%
Face-to-face (excluding Évora)	Car/taxi	59	81%	18.0	180.0	49.0	27.3	30.0	40.0	51.5	2,891	84%
	Bus	6	8%	5.0	55.0	36.7	18.9	30.0	40.0	50.0	220	7%
	Ambulance	8	11%	15.0	70.0	39.6	15.8	32.5	38.5	45.0	317	9%
	Walk	–	–	–	–	–	–	–	–	–	–	–
	Total	73	100%	5.0	180.0	47.0	25.9	–	–	–	3,428	100%
Face-to-face (just Évora)	Car/taxi	19	70%	0.5	6.0	2.8	1.5	2.0	2.0	3.0	53	76%
	Bus	3	11%	2.0	4.0	3.3	1.2	3.0	4.0	4.0	10	14%
	Ambulance	–	–	–	–	–	–	–	–	–	–	–
	Walk	5	19%	0.3	3.0	1.4	1.1	0.5	1.0	2.0	7	10%
	Total	27	100%	0.3	6.0	2.6	1.5	–	–	–	70	100%

We followed 2012 Guidelines to Defra/DECC’s GHG Conversion Factors for Company Reporting to estimate direct and indirect GHG emissions.¹² Bus emissions for teleconsultation patients were estimated using the category ‘Average local bus’ and for face-to-face patients the category ‘Coach’. All ambulance emissions were estimated using the category ‘Average van up to 3.5 tonne’. To assess the impact of the added information on modes of transport and car engine size and fuel type on the results, we estimated emissions resulting from all patients travelling in an average car using an unspecified fuel. Since the average car in Portugal is unlikely to be the same as in the UK, we adjusted the conversion factor for Defra/DECC’s category ‘Average car (unknown fuel)’, using data on average emissions of cars sold in the UK and Portugal, and taking into account that the average age of cars in use in Portugal is nine years compared to 6.9 years in the UK.^13,14

Results

Table 3 provides descriptive statistics for self-reported one-way distances, by mode of transport, from the survey. A number of face-to-face patients in our survey were from Évora (the location of the main hospital) and thus travelled very short distances to their appointments. The mean distances travelled by these face-to-face patients were actually smaller than those covered by teleconsultation patients. We thus excluded these 27 patients from the analysis, as they did not inform our understanding of what means of transport remote patients use. If we then focus on teleconsultation and face-to-face patients, excluding Évora, we notice that 39% of patients walked to the teleconsultation, avoiding costs as well as emissions and potentially improving their general health. Teleconsultation patients reported travelling an average of 5.9 km each way to their appointment, which can be compared to the average 47 km that face-to-face patients travelled. The total distance covered by teleconsultation patients was less than 20% of the distance travelled by face-to-face patients.

Table 4 shows return distances and emissions estimated for different modes of transport and car engine size and fuel for 20,824 teleconsultations. If teleconsultations had not been available, patients would have travelled 2,313,819 km more with an extra 455 tCO₂e being emitted in the process (22 kg CO₂e per patient). The use of teleconsultations resulted in a 95% reduction in GHG emissions associated with patient travel to appointments.

Table 4.

Return distances (km) and GHG emissions (kg CO₂e) by mode of transport, car fuel and engine size.

Pathway	Mode	Car type	Km	CO₂	CH₄	N₂O	Total direct GHG	Total indirect GHG	Grand total GHG
Teleconsultation	Car/taxi	Petrol, up to 1.4 litre	53,793	8845	8.1	35.0	8888	1779	10,667
		Petrol, 1.4–2.0 litre	2700	558	0.4	1.8	561	112	673
		Petrol, over 2.0 litre	675	201	0.1	0.4	201	40	241
		Diesel, up to 1.7 litre	30,258	4271	1.5	53.6	4326	859	5185
		Diesel, 1.7–2.0 litre	15,417	2709	0.8	27.3	2737	545	3282
		Diesel, over 2.0 litre	3978	930	0.2	7.0	937	187	1124
	Bus	5213	578	0.6	4.5	584	123	706
	Ambulance	1668	409	0.1	2.9	412	88	500
	Walk	8933	–	–	–	–	–	–
	Total	122,635	18,502	11.8	132.5	18,646	3734	22,380
Face-to-face	Car/taxi	Petrol, up to 1.4 litre	1,030,593	169,450	155	670	170,275	34,092	204,367
		Petrol, 1.4–2.0 litre	51,643	10,682	8	34	10,724	2149	12,873
		Petrol, over 2.0 litre	12,993	3861	2	8	3871	777	4648
		Diesel, up to 1.7 litre	579,758	81,833	29	1026	82,888	16,465	99,353
		Diesel, 1.7–2.0 litre	295,409	51,912	15	523	52,450	10,446	62,896
		Diesel, over 2.0 litre	76,225	17,822	4	135	17,961	3586	21,547
	Bus	170,552	4793	12	97	4902	1018	5920
	Ambulance	219,281	53,802	13	385	54,200	11,514	65,714
	Total	2,436,454	394,155	237	2878	397,270	80,047	477,317

Using data on average emissions of cars sold and average age of cars in use in the UK and Portugal, we estimate that the average car in use in Portugal emits approximately 7% less CO₂/km than the average UK car. Since the total direct GHG emissions for Defra/DECC’s ‘Average car (unknown fuel)’ is 0.19469 kg CO₂e/km, in Portugal this would be 0.18106 kg CO₂e/km (indirect emissions are not affected by this adjustment). Using this emission factor, we estimated total GHG emissions as approximately 510 tCO₂e. This is 12% more than the emissions calculated using information on modes of transport and car engine size and fuel. As many patients walked to their appointments, this important feature would have been missed if the analysis had focused on a single mode of transport.

We conducted a sensitivity analysis using the lower quartile (best case scenario) and upper quartile (worst case scenario) distances reported by teleconsultation patients (Table 3). In the best-case scenario, teleconsultation patients would cover about 34,000 km, in the worst-case 159,000 km. The reduction in total direct and indirect GHG emissions from the use of teleconsultations would be 448 tCO₂e in the worst-case scenario (a reduction of 94% from the 477 tCO₂e emitted to attend face-to-face appointments) and 472 tCO₂e in the most favourable scenario (a reduction of 99%).

Discussion

The use of teleconsultations in Alentejo is estimated to have led to reductions in distances travelled and associated emissions of approximately 95%, cutting GHG emissions by a total of 455 tCO₂e between 2004 and 2011 (22 kg CO₂e per patient). Even assuming upper quartile distances in the survey, teleconsultations still reduced emissions and distances by 94%.

Compared to Ontario’s reduction of 220 kg CO₂e per patient over a six-month period, the impact of teleconsultations in Alentejo seems significantly smaller.⁵ Yet, it is noteworthy that the average distance to a face-to-face appointment in Ontario was 473 km, and it was assumed that patients used a car to travel (even cases in which patients would travel more than 2000 km). Considering Defra/DECC’s coefficients, bus, train or even air travel would result in fewer emissions than using an average car. According to a review of patient travel assistance programmes in Canada, patients from more remote provinces/territories tend to travel by air or rail.¹⁵ Masino et al. themselves point out that it would be desirable to include alternatives to cars. Our own estimates show that incorporating more detailed information on modes of transport, car engine size and fuel leads to estimates which are 12% smaller than assuming all patients use an average car (510 tCO₂e compared to 455 tCO₂e). Finally, with 39% of patients in our survey reporting they walked to teleconsultations, our findings illustrate how important it is to account for different modes of transport when estimating GHG emissions.

There are limitations to our research, mainly due to availability of detailed data (e.g. place of residence of patients in our eight year data set). It would be interesting to compare the characteristics of the sample to all those who had outpatient appointments in the second half of 2011 but, unfortunately, this is not possible. Although there are publicly available data on age, sex, income and other characteristics, they refer to the population in general in Alentejo, not to those having had outpatient appointments. While extrapolating from our survey findings to a larger data set may introduce inaccuracies, it does allow the assessment of impact over a longer period. More accurate data would be desirable. However, having health care providers collect data on modes of transport, engine sizes, fuel type, and distances on a permanent basis is not feasible.

It is important to note that teleconsultations are only one example of remote care. In Alentejo, the same equipment that is used for teleconsultations is also used for teleradiology and tele-education (which were not assessed here). The total impact of the telemedicine programme in Alentejo is expected to be greater than the figures reported here. Furthermore, there are other interventions beyond telemedicine which contribute to reductions in emissions (for example, mobile breast screening).⁸

There is much potential to reduce GHG emissions by bringing care closer to patients. The challenge is how to integrate these benefits into technology assessments. One way is to monetize emission reductions in economic evaluations. Expectations are that the price of one tonne of carbon will cost $10 to $15 when California’s cap-and-trade scheme starts operating in 2013.¹⁶ This is far below the €50 that analysts believe is needed to drive low carbon investments and achieve the reductions set out in the Kyoto protocol.¹⁷ If the 455 tCO₂e avoided by teleconsultations in Alentejo could be traded as certified emission reduction credits, they would be worth between $4500 and $6800. At €50 per tonne, they would be valued at €22,700. However, reducing GHG emissions is not the main rationale for remote care interventions and is rarely even considered in current technology assessments and economic evaluations. We suggest these reductions should be considered when assessing new ways of delivering care closer to patients, and that their impact is not negligible.¹⁸ How we choose to monetize these reductions and include them in economic assessments needs exploration but if health care systems are to take action on climate change, the impact of remote care interventions on national carbon footprints must be considered.

Footnotes

Acknowledgements

We thank Manuela Rosado, José António Estrompa and the personnel at the Hospital do Espírito Santo de Évora’s Patient Management Department, Fernando Miranda, José Robalo, Hugo Quintino, Sónia Martins, Filomena Mendes and Jenny Nelson for their support and collaboration.

Funding

This research was partly funded by a doctoral grant from Fundação para a Ciência e a Tecnologia, Portugal (grant reference SFRH/BD/66305/2009). We also acknowledge the support of the UK Engineering and Physical Science Research Council’s Health and Care Infrastructure Research and Innovation Centre (HaCIRIC).

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