Hello, everyone. Let's get started here. I'm Robbie Marcus, the MedTech analyst at JP Morgan. Really excited to introduce our next company, Intuitive Surgical. I'm gonna bring up CEO, Gary Guthart , for some presentation, then we'll turn to Q&A. Gary?
Thanks, Robbie. All right. Good morning. Delighted to be here with you today. I'll go ahead and jump right in and look forward to the Q&A as well. We do have some forward-looking statements. I do recommend that you look at our SEC filings on our website to look at risks and uncertainties, and look forward to a robust conversation. Our mission and our vision, for those of you who are new to the company, we believe minimally invasive care is life-changing. It has been our mission since our start in December of 1995. I'm standing up here in a boot. That is actually a surgery that is 5 weeks old. It was not minimally invasive, we can talk about the real value of these things.
For the company, we think there's opportunity to be profoundly better, that outcomes can be not a little better, not 5% better, but a ton. The more you look, the more you double-click on these things, and look at the experience that patients actually have, look at the variance of surgeon populations and the variance of patient populations, the more opportunity there is. It's actually quite shocking as we look at it. That has driven us to new places over the last 25 years. We're starting to move kind of up the care continuum into diagnostics because we think if you can find it sooner, you can do a lot better. Waiting until it's late doesn't help, and we think we have some capabilities there.
We're moving into some opportunities post-surgery too, and most of those are around understanding and really being deep in surgical science, I wanna talk to you about that today. Just some stats to kinda center us, where are we in the world. In the last year, Physicians using our products performed just under 1.9. Our finance team, thankfully, is being conservative at 1.8. She came in just under 1.9 procedures in the year. I always ask, is that bigger or is that small? How do I think about that number? We'll put that in context in a couple of slides. Bigger than we've been and smaller than the ultimate opportunity. We are a highly studied company. I think that's great. I think it's natural.
There are about 3,000 peer-reviewed publications on our products and technologies in the year. The problem with the database isn't that it's too small. The database is so big, it's hard to sort. The vast majority of those, over 90%, are fully independently conducted and funded from Intuitive. We do some funding, but a lot of people study us without that. We put another 1,200 da Vinci systems in the world. Total experience, about 11 million procedures in the total experience for Intuitive. The database now over 35,000 peer-reviewed articles and over 7,500 da Vinci systems in clinical use. This is a habit of ours. What did we say we were gonna do last year? What things did not go well or what were we challenged by and what were the areas of strength?
We wanted to move through the back end of the pandemic well, support our customers. These are things like making sure that quality of supply is there, that they could depend on us. We wanted to make sure that our existing and new platforms were launching the way we wanted them to. We wanted to get additional indications and drive our launches. We wanted to diversify our growth outside of the United States, outside of urology. We had a good experience in urology in the year, but we wanted also to see growth outside of that specialty. General surgery has been a growth driver in the United States. We wanted to see that continue. The year was not without its challenges. Supply chain disruption was significant in the year. It's gone up and down.
It's abated a little in some places. It's not all the way gone. Inflation in costs, inflation in supply chains continues. I don't think we're through that yet. You've all seen foreign exchange impacts on revenue. Staffing constraints in some hospitals in some countries have put pressure on surgery. I think actually staffing constraints are both a challenge to Intuitive. It's also an opportunity. We actually are helpful with regard to diminishing the staffing requirements of hospitals, both in ER and post-surgery. If staffing constraints are acute for our customers, it can diminish the amount of surgery they do. If they are not acute, if they're pressured, we actually help solve it for them, which is interesting. COVID waves continue. We saw it in the fourth quarter in China.
We saw a relatively significant decline in surgical procedures performed in Q4. How long that lasts, we don't know. I think all of us have been through COVID waves now, and we know that they bite and then they end. When it ends, we'll see. When it ends, we know there'll be a backlog of patients and people who need surgery. We had areas of strength in the year. Benign general surgery growth in the United States was really strong. I'll show you a little more about that. Our Diversification outside of urology. Urology was great. I don't mean to imply urology wasn't good, but we diversified beyond urology outside the United States. That's a result of investment and focus. It's been great. Our flexible robotics platform is Ion. First indication is looking for suspicious nodules in the lungs.
That has been adopting nicely. I'm gonna share that with you shortly. We have a suite of digital technologies. I'll try to introduce them to you in a little bit of a concrete way. I'm a applied mathematician by training. Whenever I hear people talk about digital, it makes me nuts because it's so high level as to be meaningless. I try really hard not to do that. It's hard in a short setting. I'll do my best. Customer acceptance has strengthened for us in the year, and that's important. We like to look at how we do. It's better to ask our customers how they think we do, and that has been strong for us. Procedure trends. We had 18% growth in 2022. The compound annual growth rate through the pandemic was 15%.
The growth rate, entering the pandemic was, I think, Jamie, 18%-19%. We've kind of bounced back in 2022. I'm happy about that. Our anticipated growth range going into 2023, 12%-16%. That low end is really anchored on what happens in China. What's the uncertainty there? The high end is really mostly gated by how fast we can do things like training our world and the staff. I think we are the constraint on the top end, not the end market. We can talk more about that in the Q&A. On capital, if you look on that left side, that's system placements. The dark, the dark bar underneath, that is additional capacity into the field. That's people who are building capacity.
The light bar are trade-ins of older systems, generally Gen 3. We're on gen four. X and Xi are Gen 4. Product. We're at the end of the trade-in cycle for Gen 3 . You see the light blue starting to compress. That's because we've traded out with our customers most of those Gen 3s. Actually, you see a dip in 2020, the beginning of the pandemic, in folks installing additional capacity, and then it recovers. It recovers in 2021, and it recovered in 2022. That's encouraging, right? That says, hey, people got a little bit hesitant, a little bit cautious at the beginning of the pandemic. They weren't sure how it was gonna unfold. That's not a shock. It's recovered. Anyway, that's what's happening in capital.
If you look at the install base, clinical install base, those that are out there doing procedures, you see that we've grown 11% through the pandemic as a CAGR and 12% in this last quarter. I'm sorry, in this last year in 2022. It's kind of interesting that the drivers, why don't we start this way? The drivers of the business are how often do people wanna use our products? That's procedures. Are they willing to acquire the capital required to go do that, either by buying it or by leasing it or by renting it or whatever we provide for them? That's been pretty healthy. The difference between those two, 18% procedure growth, 12% install base growth, is Efficiency Gain . How frequently do they use the systems they already have?
I love Efficiency Gains . I would drive it as hard as we can. It's hard to move because it's a lot of workflow within the hospital. It's an indicator of how they run their programs, a little bit of indicator of how we design our products. We've had roughly 4% annual compound growth on utilization. Utilization is fantastic for our customer. It may suppress future capital sales. Don't freak out about that. I don't. What you really care about is are they using the products they wanna use? We'll talk a little bit about recurring revenue. The goal of the business is not to put as many capital systems out as the world wants to buy. The goal of this company is to make sure we support the procedures that need to be supported.
If we have very high utilization, it's a great return for our customers. It's a great economic situation for us. It all works great. Capital is important because it sets up the set of technical capabilities and clinical capabilities that the customer needs, but it is not the primary driver. Revenue trend, what does that look like? Here's how we've been, 12% compound annual growth through the pandemic. The dark blue bar is now moved to the sources of recurring revenue, the things we have to earn every day. That's instruments and accessories that are used as a part of every case. That's the service contracts on our capital equipment. It's rental and leasing revenue, things that are not capital sales. You've seen over time that it's grown to about 80%.
We have to earn about 80% of our revenue annually. It's more predictable. I like this setup. I think it's very healthy for the company. The reason is it keeps us really focused on the leading indicator of the health of the business. Procedure growth drivers, I told you it was 18% in the year. Some things that were accretive, things that drove growth. We said one of our priorities was to drive Diversification beyond urology outside the United States. That was 25% growth in the year. Fantastic. We said that US general surgery has been important. That's a procedure domain that is adopting. It's in the middle innings of a lot of these different procedures from bariatric surgery to cholecystectomy. That's healthy for us, 22% growth.
Then, all other, which is more the legacy side of our business, urology and some of the gynecology, also grew through the period. Not bad. Where are we in the opportunity? This is kind of a framework we shared with you last year. If you just look at the systems we have in the market, this is da Vinci and our da Vinci SP, in the countries in which we operate for the clearances, for the indications we already have, we think there's about 6 million that ought to be done this way. I just said we came in at about 1.9 million. For the products that we have, we think we're less than a third penetrated.
The things we're working on, additional indications, Ion and its growth, new ideas for SP are not yet in that $6 million. We think that opportunity gets a lot bigger, up to $20 million over time. Jamie will correct me, I think Ion is not in this slide just yet. That's true. We're not done. I think there's decades of opportunity in doing technology-enabled ecosystems to address acute care, which is how we think of ourselves. I wanna talk to you about things that may be obvious to you, but if you've been with us for a while, probably worth calling out. We are now supporting the standard of care in several surgical disciplines in many countries. That means that we're supporting procedures at an industrial scale.
If tomorrow we had to go out, if we were the FAA, if the FAA comes out and says, "Hey, our systems went down, you can't use them tomorrow." The majority of prostate cancer surgeries in the United States wouldn't be conducted. A large fraction of the gynecologic surgeries in the United States wouldn't be conducted. The majority of lung resection surgeries in the United States wouldn't be done. There's an industrial scale component of this that I think is requiring attention and investment from us. I think it is a fantastic thing. It's an honor and a privilege to do it. Done well, it builds, I think, long-term value in the company. I want us to get better at it. We have an innovation engine and it has built the company.
Now it's a left-hand/right-hand thing. We wanna make sure that we maintain our innovation edge and drive it, and also take advantage of and perform at the very highest levels at some of the industrial scale opportunities that we have. We start with the end in mind. We now do work, what this little graphic shows is preoperatively from the point of view as assessment and training and helping understand patient selection. We do work, of course, intraoperatively. Doesn't matter in the operating rooms. We wanna make sure it works in the operating room. We do a lot of work postoperatively and post-procedure analytics and the capabilities that we call surgical science. I think that our group is helping to lead an analytic understanding of surgical science, and I wanna talk more about that in the talk.
Getting there, really working across this, of course, requires engaging the customer all the way through this set of life cycles. That has been one of the missions of the company in the last 5 years, and we've gotten stronger at it. It's not enough to have some products in that space. There are attempts out there to go acquire all these little things, and they become Frankenstein. I had a foot surgery. I look like Frankenstein. It ain't good. You definitely want these things to work as a piece, so I think integration matters a lot, and I think dependability matters a lot. If you wanna be underpinning or supporting the standard of care, it's gotta work routinely, virtually all the time.
We focused the company on this, and I think it has been to our benefit. We're seeing a change in the market. We're seeing a change in the way our customers engage us. That is that we have built evidence now that this is a four-way win. It's a win for the patients in terms of better outcomes and their experience. It's a win for the care teams in terms of their experience and the amount of work they have to do. It's a win for the hospitals and providers. We are seeing in our data that it's a win for the payers. Lower total cost to treat per patient episode. It's actually a win across the floor, and we have evidence that that's true. You'd say, "Okay, well, Gary, that's nice. It's a nice chart.
This is true, just show me some evidence that that's right. Well, let's talk about what people have actually done. The top chart are integrated delivery networks, so corporate ownership of providers that own more than 20. 20 or more systems inside their institution, it has been growing sequentially every quarter. It grew 16%. It's grown all the way through the pandemic. Corporate ownership, these are sophisticated human beings. They can go look. Is it really better for our contribution or margin or not? Is it really getting us better outcomes or not? They can use electronic health record data to validate. How about hospitals, single institution, single building that has more than seven or more?
If you had asked me a decade ago how to predict that, I don't know how to have predicted, but it's grown 48% year-over-year in the fourth quarter. Hospitals that have now them lined up. When they've lined them up, they're not talking about experimentation. They're talking about standard of care. This issue of industrialization of this side of the business, I think, is evident in the data. You will see from us a set of investments. Why do I tell you all that? Well, when we talk about our investments and why we think the investments are important, that's why. We're investing to operate consistently at industrial scale to engage the globe.
We have a systematic process for identifying which countries we think we can invest in and do really well. We review that annually. Are quite disciplined about it. We're in 69 countries now. We want both strong innovation and industrial scale capability. I talked about four wins. Quadruple Aim is, of course, not our language. It's our customer's language. The four wins are just that. Can you demonstrate better outcomes through their own data, through clinical studies, and through real-world evidence? Better care team experience, better patient experience, lower total cost of care. I think the answer to that is yes. What's happening now is that we're being invited into policy conversations with governments around the world that say, "We believe the Quad Aim. We see that. We see the data.
Let's talk about improved patient access." I think we've earned a seat at a policy table that the company didn't have five years ago or six years ago. It's not because we're articulate, it's because the data shows that it works. Now one of the opportunities we get are, okay, if it really is a Quad Aim improvement, can you open access to more people in more places? Can you make sure that people get it? That's something we'll be driving in the next couple of years. Where do we go from here? What does that look like? We wanna raise surgical capabilities in hardcore ways inside the operating room, so we can start driving and continue to drive standard of care. Even today's standard of care is not good enough. There's just no question about it.
We know there's massive variation between surgical skill and care team skill. There's population variance in surgery, and we wanna do something about that. I think we can be one of the leading partners and companies in the world to make that better. We wanna make sure that we can gain efficiencies for our hospitals. Healthcare staffing is not gonna get easier anytime soon. It may be a durable problem in many aging societies. Dealing with that in terms of staffing efficiencies and costs, I think we're a part of the solution, not a part of the problem. That last point I made to you is we do think there's an opportunity to open access and to grow the capabilities of the company over time. For those of you who haven't seen it, we'll just touch on product.
Our flexible robotics program, Ion, this first indication is in the lung. A meter-long catheter, fully sensed, Shape-Sensing, fully sensed along its full length using this fiber optic system that's pretty awesome. Clinical outcomes for this in our PRECIsE trials have been great. Adoption has followed suit. This has been a demand. We have a single indication for Ion at this time, and that is for biopsy in the peripheral lung, or in the lung itself. Indications for lung cancer are high. You see it on the left. We're currently available in the U.S. That's the market we're operating in. We were granted Green Channel, so local channel access to the regulatory pathway in China. We're pursuing that.
I think that's a good sign, it's an indication of the trust that the Chinese healthcare system has in our joint venture with Fosun. We are submitted to our program for European MDR, we expect to make progress there. Install base has grown nicely. Procedures have grown nicely. We're seeing a nice traditional adoption here. Safety profile has been very good. Safety profile is as good as CT-guided needle biopsy in the clinical data that we see. The efficacy has been good as well. So far, so good. On our single port program, this is narrow access surgery going into the body through something about the size of a quarter. We're seeing really nice growth. In Korea, it is very strong.
In the U.S., it's gated by indications. We are working with clinical trial sites and the FDA to expand those indications. The platform is performing very well. I'm actually quite enthused. SP should give us pathways to new indications, and those new indications should introduce us to surgeons we've not met before, in procedure categories and segments we've not participated in. I think that's quite exciting. 38% SP procedure growth despite no additional indications in the year. We have a colorectal IDE ongoing, a thoracic IDE ongoing, and working on additional geographic clearances. We just got a broad clearance in Japan. That launch has just started. We're excited, and we will continue to drive this. Stay tuned. I talked a little bit for a minute about digital and data. What are we trying to do in digital?
We wanna make sure that we support clinical workflow and decision-making. That's an integration of what we get, the data we get out of operating rooms and integration with hospitals' electronic medical records. We wanna accelerate learning. I talked a lot about variance in care teams. I think Intuitive is an opportunity to show with data what that variance really is and to use machine learning techniques to be able to identify the sources of clinically relevant variation. There's a lot of variation. Some of it doesn't matter. The real question is, what variation is clinically relevant? I think that we have the datasets, the sensing, and the infrastructure, the back end, to be able to help our customers identify that. When you have those two sets of data, you can start driving program optimization.
We can do things that help our hospitals, our customers, save money, save costs. In the environment we're in, I think this is powerful for them and strong for us. That actually looks like different products. That's the point. I won't take you through every one of these things, but these are the products that flow through. Preoperative 3D modeling, we call it Iris. Real-time access to case reports. Think of that as Fitbit for the surgeon available on their phone right after they stand up from the case. They can look at their history. They can look at what just happened. We have integrated intuitive learning and portals that allow them to do that. We talk about personalized learning using machine learning techniques. That's the connection. We have integrated telepresence into our computing in the operating room. We have our Intuitive Hub.
Intuitive Hub is an edge computing platform. It's a smart screen that sits cloud connected in the OR, or it can be locally connected, depending on what the surgeon wants to do. That allows data for them and data for us. We're gonna talk about a Computational Observer. I had mentioned that to you maybe last year or the year before. The ability to have computational capabilities sitting over the surgeon's shoulder and giving them some insights. We call that Procedure Review. I'm gonna touch on that in one minute. All of this goes through a single integrated entry point into the surgeon's hands and allows them to do things like order and maintain a relationship with us, multi-platform aligned. That's what they do.
If you ever go out to one of the trade shows and walk through it, you'll see these various products. This is the point. This is what we're trying to achieve. Just to give you a little sense of is it actually happening, again, kinda trying to keep it real. Virtual reality training is a routine part of robotic-assisted surgery training on da Vinci. It happens everywhere all the time. It grew 25% year-over-year last year. We've put our smart technology, our edge computing into operating rooms. It had 200% growth in procedures captured on da Vinci in the last year. People are appreciating it. Gives them fast access to the data and the video that they just had. It's extremely easy to use. Quite powerful.
The use and registration of our My Intuitive app, the mobile portal, grew almost 600% in the year. These things are real. They're showing up in the hands of our customers, and they're adopting it. I have talked to you about Computational Observer. I just wanna talk about it. We're now in about a dozen academic research institutions working closely with clinicians on meaningful surgical science. If we have all this data, what can we do with it? We have some other data sensors coming too.
The kinds of things that they're interested in doing are looking at how they're performing against expert surgeons, having correlation-based analysis that determines where they're doing something differently. Connecting that to the electronic health record over large data sets so that they can tell whether that's clinically meaningful or is that a style difference. Then feeding it back to say, "Okay, if this is where you're struggling, this is who you ought to go talk to, perhaps in proctoring. This is what you might practice in virtual reality. Here's a way to connect the loop." Is it all validated yet? No. Does it work? I think it works. Have we done all the academic validations? That is to be done. That's why we're working with multiple academic medical centers to help us with it.
It's a multi-year journey. The promise is quite high. The demand is off the charts. The, the rate-limiting step is really how fast we can learn and how fast we can deploy. I don't think this will be a huge revenue driver. I don't wanna leave you with that impression. I think what it is the core science that allows us to innovate with our customers going forward. Our, our goal is not to perfect this and then charge an arm and leg for it. I think what it is, it's a partnered effort with customers to generate insights that will drive surgery in a better direction. I think with our products and services, that will open opportunity, and we will pursue it. In terms of Net Promoter Score, this is done blinded.
It's a J.D. Power-based survey. It's not ours. They go out and survey our customers, compare us to competitors and other things. We grew again in the year. Customers are appreciating our efforts and our approach, we're told. World-class is above 70. We're running at 79. Why do they do it? What do we think is happening here? I think database engagements with them, Quadruple Aim demonstration, real-world evidence builds belief. Our dependability of our systems and dependability of our staff is very high. The learning, innovation, and excellence, the investments in surgical science are highly appreciated. Our team has been very good and flexible with capital acquisition models. We've allowed them to reduce their costs while maintaining a strong economic performance for Intuitive. I think that's appreciated.
We're able to bring them analytics insights that are hard for them to generate themselves. I'm shocked because they have very large data investments in electronic health records, and yet we still are able to routinely share with them opportunity. In closing, what are we driving this year? We wanna continue to increase utilization and penetration in the target procedures we think are important. Those are by country, by specialty, and we have strong tactical plans and investments to support those efforts. On our innovation fronts, we're expanding indications and launching our new platforms, SP and. A focus on quality of supply and reliability of supply as we emerge from pandemic stresses remains important. Our supply chain and logistics are not fully settled yet.
We have an opportunity as we move to industrial scale to be more efficient inside our company, and to drive both better quality out of organization at a lower cost, and we're gonna do that. We're making some automation investments inside the company, whether it's factory automation or workforce automation and some things that can help us. With that, I'm happy to go Q&A. Sorry if I ran a little over.
Hey, Jamie. Great to see you.
Happy New Year.
You too. You can sit there. Given the nature of your business and your global span, I thought we could kick it off with your views and on the health of the capital equipment environment, what you're seeing around the world, and any color U.S. versus OUS.
Jamie, I'm gonna let you jump.
Yeah. I'll frame first with reflecting on 2022. If you look at 2022, system placements were down 6%. We have to kind of double-click. If you look at trade-ins, we saw about 510 trade-ins in 2021. That was down to 345 in 2022, and that really reflects the kind of decline in the installed base of SIs in the field. If you look at where we are at the end of 2022, there's about 134 SIs left in the U.S. U.S. has been driving our trade-in volumes. Trade-ins in the year in 2022 were down by about a third. If you look at incremental placements, greenfield accounts, let's say net new, they grew 10% in 2022.
If you look back to earlier in the year, what we described at the end of Q1, we saw it into Q2, was kind of an elongation of our capital pipeline. It really reflected, given pressures customers were under with staffing, with increased interest rates, et cetera. We saw customers start to take a close look at their capital budgets and reprioritize. That took some time. Come to the end of Q3, what we saw was customers resolve that process, start to establish what their priorities are. More recently, what we've seen on the capital front is where customers have healthy growth in robotic procedures, da Vinci is a relative priority in their capital budgets. We saw them then invest in Q3 and Q4, and you see that kind of reflected in the results.
As you talk to customers from a capital perspective, they are clearly still cautious. I think staffing pressures are better today than what they were earlier in the year, but labor costs are still higher than, let's say, pre-pandemic levels. Vacancy rates are still higher than pre-pandemic levels, even though they're a little better. Of course, those customers that have debt have higher interest rate expenses, et cetera. Supply chain and inflation is having an impact on everybody, including customers. I'd characterize the capital environment as cautious. When you look at, let's say, 2023, what are customers doing with their capital budgets, I don't think we have yet any particular highlights that I would kind of comment on. I would just say that customers are cautious. There's still a number of risks and uncertainties in the macro.
There's a question of whether there'll be recessions. We'll see. I'd characterize it as cautious.
If we look at the pre-announced numbers and guidance for today, fourth quarter procedures up 18%. Maybe you could give us a little more color on how that trended geographically. China's been a difficult environment. We see on the news how that impacted. While you're at it, maybe also talk on the 2023 procedure growth at 12%-16%. Gary, you touched briefly on what's included at the low and the high end, usually give a little more robust color. Any additional commentary there would be great.
Yeah, Brian, why don't you jump in?
Sure. Why don't I start off on procedure guidance first. Procedure guidance for us for 2023 is 12%-16%. At the low end of the range, it assumes ongoing choppiness with COVID hospitalizations and also staffing pressure at hospitals throughout the year. In addition to, as Gary has noted, and in your question as well, assumes just significant ongoing challenges with China. Right? You really can't predict what's gonna happen there throughout 2023. In addition to just uncertainty with timing around the quota for capital. At the high end of the range, it assumes no real significant impact from COVID throughout the year, in addition to, say, ongoing growth in general surgery in the U.S. and diversified growth outside of the U.S., beyond urology, again, similar to what Gary had presented.
In that range, it does not reflect significant material supply chain disruption, throughout the year or any hospital capacity constraints similar to what we had seen at the beginning of the pandemic.
With respect to maybe Q4 procedure trends, actually what you saw was the U.S. and OUS procedure growth were both the same at 18%, I believe.
That's right.
That 18% OUS growth is normally above the U.S., impacted by what we saw in China. We started to see kind of a slow or moderate impact to procedures in China at the beginning of November. That accelerated through the remainder of the quarter. Last two weeks, procedural impact in China from COVID as cases rose and as they kind of eliminated their zero COVID policy, was a significant reduction in procedures in the last couple of weeks. That will continue into Q1. Obviously, we don't know how long that will persist. Our historical experience, as Gary referenced, was that at some point that recovers as you accumulate a backlog of patients and as COVID pressures ease.
Ravi, I overran my time. We're gonna do a lightning round now, though, so you get to your questions. We'll keep them pithy on our end.
No, just a few more. Two I really wanna get to. Spending. We've seen Intuitive Surgical materially increase its spending over the past few years. You've added a lot of headcount at the business, a lot to R&D. You've also talked about in the last earnings call how you're going to moderate your level of spend. Year-over-year growth will be less in 2023 versus in 2022. Two parts here. Maybe directionally, how do we think about how much you're moderating spend? Second, where is the spending priorities and what are you investing in at the company?
Yeah. Just maybe quickly on some framing. If you look at Q3 year to date, we haven't released our Q4 results yet, OPEX as a percent of sales was about 34%. Just as a comparator, pre-COVID, 2019, OPEX was about 32% of sales, so about a 2 percentage point difference. That increase is predominantly in our newer, earlier areas, Ion, SP, our digital investments. There's a little bit of higher regulatory costs given changes in requirements in the regulatory environment, and we've been investing in our infrastructure for the industrial scale that Gary described. If you look at our operating expenses as we report it on a pro forma basis, we're actually at the lower end as a percentage of sales relative to our MedTech peers, largely because our SG&A rates are pretty low.
If you look at 2023, what we've said is our operating expense growth will be below what we saw in 2022. 2022, we guided plus 21%-23%. That reflects some leveraging in enabling functions and the sequencing of certain investments. For R&D and SG&A at this point for 2023, obviously, we'll talk about it more on the earnings call, I'd expect them actually to grow at similar rates next year. There's obviously some mixes in there in SG&A. We're investing overseas given the growth opportunities there. We're leveraging some of the G&A functions. It will net to about, for SG&A, a similar growth rate to R&D.
Two comments on my side. If you just kind of do a double-click on hiring, what have we hired? Highest category is manufacturing, folks who put the product together. In some places, we've insourced some technologies that we think are either important from a supply chain robustness point of view or a cost for the customer point of view, has driven some manufacturing headcount. I think it makes tons of sense. Second category was commercial. Got to go reach out and touch all your customers. I think that's been really good. Third category has been engineering. We're not spending too much on R&D. I am not struggling with the level of investment in R&D. I think it's healthy. I think it's justified. Some things have been taking longer than they were historically.
A couple of things are behind that. Supply chain disruption has made it hard for some developers, and the second part of that has been regulatory environments globally have changed data requirements. That aggravates me, and I'd like to see us increase cadence, but that cadence is interacting with the environment, and we're gonna have to work on it.
Maybe the last question ties in a little bit with your spending priorities, at least the way I'll ask it is competition. You've spent $ billions over the years, 20 cumulative years of experience. You had a huge number of institutions with 7-plus systems, and as you said, this is more a proven idea versus experimentation. Right now it's pretty much monopoly around the world. You have some new competitors coming in. How are you treating the competition, and what are you doing to make sure that it basically remains a near monopoly?
Yeah, I'll reject the framing of monopoly and near monopoly, let's just stop that. The, what do we look at and what do we think at? First, customers appreciate choice, they have it. There are systems being sold by competitive companies all over the world, in Korea, local competition in Japan, local competition in Europe and additional. There's actually competitors in the U.S., and there'll be more. How do we look at that? I think, first of all, there's the validation of the space that technology-enabled ecosystems matter to customers. It's not just a robot. First of all, robots aren't commodities. They're not there yet. It's not that you walk up to one of these things, they all do the same thing. They all work the same way.
Technology is not at that point. It may become that over time, but it's not there. That's one. It's not enough. You want the entirety of the instruments and accessories, the imaging systems, the data that wraps it, and you need the dependability. We think if we do that well, customers will evaluate other options. I encourage them to do so. My thing is, you know, try before you buy. Make sure you know what you're buying. Remember, you're gonna live with this thing, and that has gone well for us. As other companies have put more salespeople out into the market, we've seen total market growth grow and we've competed well with that. We wanna be first choice of customers for the right reasons, and so far, so good.
Well, great. We're out of time. I appreciate the time. Thank you so much.
Thanks much.
Thanks, everyone, for listening.