The Economic and Cognitive Effects of Pain Reduction

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University of Pennsylvania




Pain, Chronic


Drug: Ibuprofen 600 mg
Dietary Supplement: Prenatal vitamins

Study type


Funder types




Details and patient eligibility


Physical pain is a common but largely overlooked aspect of the lives of the poor. Not only does pain directly reduce life quality and happiness, it may also hamper cognitive function and, consequently, decision-making, productivity, and earnings. Workers with chronic pain may work fewer days, take longer breaks, and make less-considered choices regarding inputs; all outcomes that would reduce output and lead to greater impoverishment or impede the productivity and profitability of microenterprises and firms. The investigators will take the first steps in understanding the broader causal impact of physical pain on the cognitive and economic lives of the poor via a randomized controlled trial (RCT). 450 low-income women in Chennai, India, will be assigned to one of three treatment arms: 600 mg of over-the-counter pain medication, a placebo pill, or no medication. The research will quantify the causal impact of reduced pain on previously unstudied outcomes essential to escaping poverty including cognitive function, productivity, and earnings.

Full description

The investigators propose to evaluate the effect of reductions in chronic physical pain on cognitive function and productivity among poor individuals via a simple intervention using over-the-counter (OTC) pain medication. To do this, the investigators will enroll 450 low-wage female workers in Chennai, India into a two-day randomized controlled trial in which 150 randomly selected participants will receive OTC Non-steroidal Anti-inflammatory Drugs (NSAIDs; namely, Ibuprofen) at FDA-approved levels of one dose of 600 mg each on a single day, 150 participants will receive a placebo pill, and 150 participants will serve as a no-treatment control group. Participants will complete a detailed survey, a battery of cognitive tests, pain measurements, a task to objectively scale each participant's pain assessments, and a task designed to measure economic productivity as detailed below. Study location: The study will be based at the Behavioral and Development Economics Lab in Chennai, India, founded by PIs Schofield and Schilbach in conjunction with a local institution, the Institute for Financial Management and Research (IFMR). Sample: Participants will consist of female flower stringers in Chennai, India. Flower stringers are self-employed individuals typically working on the streets. These women purchase flowers in the morning, string them together, and sell the strands to customers passing by. Their average daily income is Rs. 250-500 (approximately $4-9). Preliminary survey evidence suggests a higher prevalence of physical pain among older individuals; hence, this study will limit enrollment to individuals aged 25 to 65 years. The investigators focus on this population for several additional reasons. First, the nature of their work (stringing flowers while sitting on the floor for most of the day) causes high levels of pain. Second, due to the societal norms in the area, women do not regularly consume significant amounts of alcohol, substantially lowering the risks associated with taking pain medication. Third, the nature of their work makes flower stringers' productivity easily measurable (length and weight of flowers strung). Finally, although this population is specific, participants are similar in many ways (e.g. age, education, labor habits) to many workers in the informal sector, improving the study's external validity. Recruitment and screening: Surveyors approach potential participants at their place of work (typically a stand on the side of the street). The surveyor shares information about the study, while also conducting a broad first screen for eligibility. If participants are interested in participating and pass the initial screening, they schedule a time to come in to the lab for Day 1 (see below for further detail on the timing of the study). On Day 1, all potential participants are further screened to ensure: 1) their primary profession is flower-stringing, 2) they do not have any health conditions which are contraindicated for taking ibuprofen, 3) they regularly experience pain from their work, and 4) they are between the ages of 25 and 65. Timing: Day 1: Following field recruitment, potential participants are screened for eligibility and complete an informed consent process. If eligible, participants complete the survey measuring demographics, work habits, and data on the type and amount of pain typically experienced. Participants also complete the battery of cognitive assessments. The investigators will randomize using Stata and then reveal the experimental condition assignment to individuals privately. Any non-compliance will be carefully tracked. Day 2: Participants complete the battery of cognitive tasks and 30 minutes of flower stringing in the morning (pre-treatment). Participants report their pain levels periodically and complete a "pain calibration" by reporting their pain levels while holding their hand in cold water. They are then randomly assigned to one of the three experimental arms at lunch. After lunch, all participants complete another 3 hours of flower-stringing and repeat the battery of cognitive tasks. Participants also complete a "pain tolerance test" after lunch. In this task, participants are paid for the time they leave their hand in cold water.


139 patients




25 to 65 years old


No Healthy Volunteers

Inclusion criteria

  • Must be between the ages of 25 and 65
  • Must speak Tamil as their primary language
  • Must report that they have suffered from chronic physical pain in the last week.

Exclusion criteria

  • An adverse relation related to pain medication in the past
  • Kidney disease (ongoing or kidney stone within the past 3 years)
  • Gastrointestinal (GI) discomfort
  • History of complicated peptic ulcer disease
  • Currently using NSAIDs, aspirin, corticosteroids or anticoagulants
  • Allergies to any of the medicines use in the study
  • History of gastric bleeding
  • History or existing liver disease
  • Surgery within 1 to 2 weeks after the study
  • Hypertension
  • Heart disease or failure
  • Diabetes
  • Lupus
  • Blood clotting
  • Actual or potential pregnancy
  • Use of contraindicated medications (including anticoagulants)
  • Suicidal thoughts
  • Consumption of more than 14 alcoholic beverages a week.

Trial design

Primary purpose




Interventional model

Parallel Assignment


Triple Blind

139 participants in 3 patient groups, including a placebo group

Ibuprofen 600mg
Active Comparator group
Treatment group participants receive a single 600 mg of over-the-counter ibuprofen.
Drug: Ibuprofen 600 mg
Prenatal vitamins
Placebo Comparator group
The placebo group participants receive a single dose of a pre-natal multivitamin.
Dietary Supplement: Prenatal vitamins
Control group
No Intervention group
Control-group participants are not provided with any treatment and they are fully informed regarding their treatment status.

Trial documents

Trial contacts and locations



Data sourced from

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