My wife answered our telephone. A representative of the state university asked her about my interest in participating again in her group’s research project. She handed the handset to me. For several years, my name has resided in the database of their Office of Human Research. My honoraria, when they offer one, have ranged from a crisp, minimally circulated $50 bill, to gift cards of $15 to 50, and an occasional check, peaking at $150 for doing some physical activity that other 70-somethings might prefer to avoid.

I’ve walked on a treadmill wearing a device that measures oxygen consumption. My head has endured not only the clanging of their research lab MRI scanner, but an experimental vibratory stimulus to my occiput, intended to discover something for their principal investigator that I did not entirely understand. Those grad students seemed taken aback when I asked to see my image, pointing to my sella, much as any worthy retired endocrinologist might. They graciously copied my image onto a CD, now tucked in a desk cubby.

I’ve yet to consent to studies that entail risk, though I’ve declined a few. A regional medical center once recruited me for a sleep study by online screening. I wanted a free polysomnogram. They wanted volunteers with minor sleep disturbances to be randomized to testing a new version of an old hypnotic. No sleepers for me, but it added an incentive to take a second look at my sleep hygiene.

Like others retired, I strive to visit the grandchildren and avoid visiting my doctors. My pill case has a few tablets. Doctors have advised me and occasionally invaded my innards. So did I to other trusting souls during a gratifying career. Every medical advance depends on defined groups of people agreeing to risk some uncertainty, and sometimes their safety. Many like me have no serious conditions. My state university research center often solicits me as a control participant, the chance to define normal, or at least functional aged. Others, more accurately patients than subjects, consent out of desperation. Their lives have a foreseeable endpoint that current treatments have already failed to improve.

Every pill I swallow each day required somebody else to take it previously: first healthy volunteers to assess safety, then a few trials of efficacy, then larger studies which when analyzed determine a balance between therapy and harm. Regulators, often experienced with their own projects, assess pooled outcomes, which become practice options for active physicians.

When somebody could use a participant, I’m there. As a Lifelong Learning student at the state university, representatives from the research center set up tables to attract volunteers between classes. When COVID shifted us to our Zoom screens, traffic at these tables waned. New study notifications arise by email or Facebook. Many originate at large academic medical centers with extensive dependence on human research. They have created elaborate systems for recruiting their research volunteers. Having now engaged in a few projects, the Office for Human Research knows a bit about me. My mind. My willingness to incur some discomfort. I don’t know if their spreadsheet has a searchable column for who’s a good sport, but I’d appear in there if they did.

I answered this call. Cognitive research. I’d helped that department before. Did I still qualify? Self-assessment of my health and mental function? I’m still a control. Medication list. Nothing affecting the mind, either to improve it or contribute to future deterioration, though decline might interest the researchers. Mini-testing. I remembered five words ten minutes later. I’ve mastered Serial 7s down by now. The examiners stop me at 51, remarking how easily I can subtract. The screener on the phone asked me the year. In January, the checks I write sometimes get this wrong. This January afternoon I responded with the correct New Year. I qualified.

Big challenge: Name somebody other than my wife who knows me well enough to attest that my mind remains at the level they test it. I don’t know if their panel assesses for loneliness or social isolation. And some people, including seniors, have a preference for solitude without experiencing the pangs of loneliness. I may not have a friend to help me position my mattress or schlep me to my next colonoscopy, but somebody who need not leave home can convey to a researcher when I am affable and when I am ornery. No physical effort required. No money for my friend, but a $50 honorarium for me. Money donated, gift cards indulged on myself.

While my best self tries to rationalize altruism, it’s hard to overlook what’s in it for me. Two years ago, I could not have completed my most physically demanding study. The university’s Gait Mechanics division sought to study strength, stability, and stamina across different populations. I came to their lab several times. When instructed, I inserted my right leg into a contraption that measures the strength of my quadriceps. “Push, Push,” they urged me with each calibration. I overcame graded resistance. I watched tracings of different colors appear on a screen to my right in real time.

Then some timed walks recorded with a camera. Each visit had me do 30 minutes at 3.0 mph on their treadmill. Only after I demonstrated safety would they trust me to walk at a similar speed for thirty minutes on my own, wearing sensors placed on my right thigh, right calf, and multiple places atop my right sneaker. I chose a regional mega mall as a place free of hot summer weather or rain. Through the wizardry of texting, the researchers periodically instructed me to walk faster or slower as they monitored those applied sensors in real time. Other shoppers, many also there for the mall’s air conditioning, walked much more slowly as they browsed window displays and kiosks.

For all the projects that got my Declaration of Helsinki consent, I’ve not personally met a single principal investigator. Instead I encounter graduate students and technicians. Most seem promising young scientists who make me optimistic that medical care will survive the turmoil of my late career. Several told me that the hardest subjects to recruit are men like me, those fortunate enough to reach threescore and ten largely unscathed with a willingness to help out for minimal personal reward. Their recruitment struggles surprise me. As both physician and patient I have benefited from the generosity of research volunteers. In retirement I still read medical journal articles each week that often depend upon thousands of consenting individuals doing their part in research empires. Enough people respond yes when recruited. I often ask the graduate students who tend to me personally where the information they learn from me will appear. Few even know if they will fly to their next professional convention with a poster rolled safely into a protective cylindrical container, let alone have their name among the authors in a prestigious journal.

Few seem interested in me beyond pleasantries about my family. Not my background, career, or research experience. For many, I supply a source of data that will move them ahead to their next academic degree. None talk to me much about their lab’s overriding purpose. As a Fellow in Endocrinology, I knew where each professor’s interests clustered. Our department operated through a very substantial grant successfully obtained by our Chief. The grant proposal allocated funds for the specific projects of each professor. One investigator in our lab recruited me as a control, deducing my normal gonadal function from my two preschoolers. The university sent me a check for $10 for that red-top tube. Pituitary function assessed. Results never conveyed to me.

I’m fundamentally an affable chap with ample unstructured time. Only through medical journals do I encounter outcomes of studies involving thousands. Too often these people get solicited to mitigate ongoing or future catastrophic conditions. All doctors must determine who needs surgery, identify safe and achievable lipid levels, and discover if we can manage malignancies with less toxic interventions. Subjects offered entry into studies may decline, and many do. A predictably short longevity with current treatment can change a person’s view of unknown risks of untried treatments. Regardless of how volunteers like me enter as research subjects, we all possess a generous spirit. Some even assign their final remains for novice students to dissect. We are assured anonymity, not just to the journal readers but to each other. My performance numbers will get pooled, averaged, and conclusions drawn.

That data from human volunteers enabled me to advise patients throughout my career. It would be unthinkable to begrudge the next generation their chance to poke and prod me to advance public good. My anterior thigh strength data might appear on a poster at a conference while the lovely grad student tells its significance to others who stop by to display their own professional interests.

Richard Plotzker is an endocrinologist.