Honesty with doctors is a bedrock of proper care. If we hedge in answering their questions, we're hampering their ability to help keep us well.
But some people resist divulging their secrets. In a 2009 national opinion survey conducted by GE, the Cleveland Clinic and Ochsner Health System, 28 per cent of patients said they "sometimes lie to their health care professional or omit facts about their health." The survey was conducted by telephone with 2,000 patients.
The Hippocratic Oath imposes a code of confidentiality on doctors: "I will respect the privacy of my patients, for their problems are not disclosed to me that the world may know."
Nonetheless, patients may not share sensitive, potentially stigmatizing health information on topics such as drug and alcohol abuse, mental health problems and reproductive and sexual history. Patients also might fib about less-fraught issues such as following doctor's orders or sticking to a diet and exercise plan.
Why patients don't tell the full truth is complicated. Some want to disclose only information that makes the doctor view them positively. Others fear being judged.
"We never say everything that we're thinking and everything that we know to another human being, for a lot of different reasons," says William Tierney, president and chief executive of the Regenstrief Institute, which studies how to improve health-care systems and is associated with the Indiana University School of Medicine.
In his work as an internist at an Indianapolis hospital, Tierney has encountered many situations in which patients aren't honest. Sometimes they say they took their blood pressure medications even though it's clear that they haven't; they may be embarrassed because they can't pay for the medications or may dislike the medication but don't want to offend the doctor. Other patients ask for extra pain medicine without admitting that they illegally share or sell the drug.
Incomplete or incorrect information can cause problems. A patient who lies about taking his blood pressure medication, for example, may end up being prescribed a higher dose, which could send the patient into shock, Tierney said.
Leah Wolfe, a primary care physician who trains students, residents and faculty at the Johns Hopkins School of Medicine in Baltimore, said that doctors need to help patients understand why questions are being asked. It helps to normalize sensitive questions by explaining, for example, why all patients are asked about their sexual history.
"I'm a firm believer that 95 per cent of diagnosis is history," she said. "The physician has a lot of responsibility here in helping people understand why they're asking the questions that they're asking."
Technology, which can improve health care, can also have unintended consequences in doctor-patient rapport. In a recent study of 4,700 patients in the Journal of the American Medical Informatics Association, 13 per cent of patients said they had kept information from a doctor because of concerns about privacy and security, and this withholding was more likely among patients whose doctors used electronic health records than those who used paper charts.
"It was surprising that it would actually have a negative consequence for that doctor-patient interaction," said lead author Celeste Campos-Castillo of the University of Wisconsin at Milwaukee. Campos-Castillo suggests that doctors talk to their patients about their computerised-record systems and the security measures that protect those systems.
When given a choice, some patients would use technology to withhold information from providers. Regenstrief Institute researchers gave 105 patients the option to control access to their electronic health records, broken down into who could see the record and what kind of information they chose to share. Nearly half chose to place some limits on access to their health records in a six-month study published in January in the Journal of General Internal Medicine.
While patient control can empower, it can also obstruct. Tierney, who was not involved as a provider in that study, said that if he had a patient who would not allow him full access to health information, he would help the patient find another physician because he would feel unable to provide the best and safest care possible.
"Hamstringing my ability to provide such care is unacceptable to me," he wrote in a companion article to the study.
Technology can also help patients feel comfortable sharing private information.
A study conducted by the Veterans Health Administration found that some patients used secure e-mail messaging with their providers to address sensitive topics - such as erectile dysfunction and sexually transmitted diseases - a fact that they had not acknowledged in face-to-face interviews with the research team.
"Nobody wants to be judged," said Jolie Haun, lead author of the 2014 study and a researcher at the Center of Innovation on Disability and Rehabilitation Research at the James A. Haley VA Hospital in Tampa. "We realised that this electronic form of communication created this somewhat removed, confidential, secure, safe space for individuals to bring up these topics with their provider, while avoiding those social issues around shame and embarrassment and discomfort in general."
USC's Ellie shows promise as a mental health screening tool. With a microphone, webcam and an infrared camera device that tracks a person's body posture and movements, Ellie can process such cues as tone of voice or change in gaze and react with a nod, encouragement or question. But the technology can neither understand deeply what the person is saying nor offer therapeutic support.
"Some people make the mistake when they see Ellie - they assume she's a therapist and that's absolutely not the case," says Jonathan Gratch, director for virtual human research at USC's Institute for Creative Technologies.
The anonymity and rapport created by virtual humans factor into an unpublished USC study of screenings for post-traumatic stress disorder. Members of a National Guard unit were interviewed by a virtual human before and after a year of service in Afghanistan. Talking to the animated character elicited more reports of PTSD symptoms than completing a computerized form did.
One of the challenges for doctors is when a new patient seeks a prescription for a controlled substance. Doctors may be concerned that the drug will be used illegally, a possibility that's hard to predict.
Here, technology is a powerful lever for honesty. Maryland, like almost all states, keeps a database of prescriptions. When her patients request narcotics, Wolfe explains that it's her office's practice to check all such requests against the database that monitors where and when a patient filled a prescription for a controlled substance. This technology-based information helps foster honest give-and-take.
"You've created a transparent environment where they are going to be motivated to tell you the truth because they don't want to get caught in a lie," she said. "And that totally changes the dynamics."
It is yet to be seen how technology will evolve to help patients share or withhold their secrets. But what will not change is a doctor's need for full, open communication with patients.
"It has to be personal," Tierney says. "I have to get to know that patient deeply if I want to understand what's the right decision for them."