BiCARB Study - Does oral sodium bicarbonate therapy improve function and quality of life in older patients with chronic kidney disease and low-grade acidosis?

What will happen to me if I take part?

The study takes 2 years in total to complete.

The study is of randomized, doubled blind design. This means that you will be asked to take medication by mouth three times a day. This will either contain bicarbonate, or a placebo (dummy) medication. The one that you will be given is decided in a random way (a bit like tossing a coin, but done by a computer.)  Neither you nor the research team will know which you are taking until after the study is finished. This means that the results of the study cannot be influenced by you or the researchers knowing what you are taking.

You will be asked to come to your local hospital on six or seven occasions over the two year study. We can reimburse travelling expenses or provide a taxi to transport you to your local hospital and back for each visit. We will try and make sure that these visits happen when you are at your local hospital for other clinic appointments.

The first visit is a screening visit to make sure that the study is suitable for you. It will last for approximately 30 minutes. We will ask you to sign a consent form indicating you wish to take part in the study. We will measure your blood pressure 3 times while you are sitting down. We will then take a teaspoon of blood, and ask about your medicines and illnesses and check your hospital notes. If the study is suitable for you, we will then ask you to come along for the baseline study visit (depending on how recent you have had blood samples taken at clinic or by your GP, we may be able to combine your screening visit and the next visit.). At this visit (approximately 90 minutes):

  • We will measure your blood pressure and pulse 3 times while you are sitting down. We will check your height and weight
  • We will take a blood test (about four tablespoons.)  Some of the blood taken will be tested straight away in the local NHS laboratory, while some will be transferred to, stored and analysed at the end of the study at specialist laboratories by members of the study team (research bloods.)  With your consent, tiny samples of blood serum and plasma obtained from these research bloods will be stored for up to 15 years in a clinical laboratory at the University of Dundee under the custodianship of Dr Miles Witham (Chief Investigator.)  Your research bloods are stored using a unique study code which is non-identifiable. Blood samples are not taken for genetic testing.
  • We will ask you to bring a urine sample with you
  • We will give you a health diary to complete which will record any health problems you may have had in the previous month
  • You will be asked to do some mobility tests: - standing tests, balance tests, timed getting up from a chair and a test to measure your hand grip strength
  • You will be asked to walk up and down a corridor for six minutes at your own pace. We will measure how far you can walk in that time
  • We will ask you two questionnaires about your quality of life and how your kidney problems affect your quality of life
  • We will issue your study tablets
  • We will issue you with a study pack which will contain: contact and appointment cards and a diary to record if you have experienced any falls.

We will ask you to return for further visits after three months, six months, a year, and at two years, where we will repeat the above tests. Each visit will take around an hour to complete.  For each visit we ask you to bring all your study medication containers (empty or full) and your diary.

At the 3 month visit we take a blood sample to measure your sodium bicarbonate level.  If it is found to be below a certain level we will ask you to increase your study medication to two tablets three times a day.

However, we will not receive this result straight away, so we will send you home from the visit with enough medication to last a further seven days. As soon as we receive your results we will send your new batch of tablets to your home by registered post or to your GP practice for you to collect with instructions of the dose you should take which will either be to stay the same, or to increase the number of tablets.  We will give you a call as soon as we know that you have received your tablets to go over the dose requirements and answer any questions you may have.

You will continue on this dose for the rest of the study. If you are having any difficulties or experiencing any side-effects taking the tablets, please call, so we can discuss possible solutions.

We will give you a call at 15 and 21 months after you have started the study. These brief telephone calls will check that you are keeping well and managing to take the study medication. In between these two calls, at 18 months, we will ask you to come to hospital for a brief visit to collect your next supply of study medication and ask a few questions about your general health.

In addition, we will send you a copy of the study’s Newsletter which will keep you up-to-date on the study’s progress and if you have access to the internet you can log onto the study’s website; for updates.