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Folks out there, I get that digital pregnancy test kits are a bit of a rip off, but having worked in diagnostic companies that make lateral flow devices (LFDs) for years, there are a few points I& #39;d like to make.
- The strip (see picture for example of a strip) that forms the basis of a pregnancy test itself is an immunoassay that costs a couple of cents to produce as the components are cheap, established & easily available. For some tests, reagents can be costly, but not for pregnancy.
- That said, manufacturers source components for LFDs in different places, & like any product, the components can be of varying quality. It& #39;s more complicated than generic vs branded drugs, as there is a greater component of user variability involved, but it& #39;s the same principle.
- Adding components like cassettes or digital displays add significantly more cost per device, in terms of material costs, validation, handling, packaging, storage, & shipping. These components don& #39;t change the underlying immunoassay quality but they do reduce the risk of errors
- Pregnancy test kits are sold to people who may desperately want to be pregnant, or to the & #39;anxious dreaders& #39;, those who really don& #39;t want to see two lines at all. There are some who aren& #39;t so emotionally invested, but manufacturers are cognisant of the fact that for many,
there is high emotional investment in the test result. Making a home testing kit as simple and robust as possible reduces the chance that the user will end up with an incorrect result as a consequence of their stress-induced error.
- Though you& #39;d think that peeing on a stick & counting the lines afterwards is the simplest test around (and it probably is), you& #39;d be surprised how many ways it can go wrong, especially in times of extreme stress. I& #39;ll mention some of the ways but this is not an exhaustive list.
- people don& #39;t pee for long enough meaning that not enough flow gets to the test line
- or they pee but partially/fully miss the pad
- or they pee in the wrong place and flood the device meaning the reagents don& #39;t flow in the right direction
- or they drop the test into the loo
- or they pee but partially/fully miss the pad
- or they pee in the wrong place and flood the device meaning the reagents don& #39;t flow in the right direction
- or they drop the test into the loo
- or they don& #39;t wait long enough for a test line to develop
- or they wait too long and a faint test line appears because of bleeding
- or a test line is very faint and the user wrongly interprets it as a negative (see below) or positive
- the test is used too soon for detection
- or they wait too long and a faint test line appears because of bleeding
- or a test line is very faint and the user wrongly interprets it as a negative (see below) or positive
- the test is used too soon for detection
- Couple these ways that things can & do go wrong, with highly stressed but motivated users, and it& #39;s easy to see why manufacturers invest in reducing the risk of these errors occurring with optimisation & innovations. Some manufacturers lead with these innovations. Most follow.
- Digital display was just one of these innovations. While again, the underlying test strip is based on the same principle as other home pregnancy test kits, digital display takes some of the guess work out of reading results. While this small study is industry sponsored,
and I would expect a smaller effect in real life, the results demonstrate that even without emotional investment (the women were interpreting randomised results from pooled urine samples), that people interpret test lines differently & often incorrectly. https://www.tandfonline.com/doi/abs/10.1185/03007990802120572?src=recsys&journalCode=icmo20">https://www.tandfonline.com/doi/abs/1...
- Other innovations include earlier detection, shorter time to result, longer shelf life, more controlled wicking etc. Manufacturers make tiny incremental improvements because there is a market of stressed people out there wanting the most accurate results possible, faster.
- I get the cynicism and skepticism about the pricing of digital pregnancy test kits. I really do. If I required a home test, I& #39;d likely opt for a good quality generic non-digital kit saving myself a few quid, but I would do so with the understanding that in a stressed situation,
I& #39;m more likely to make a mistake somewhere along the line. If I want to reduce the chance of my error very slightly, and increase my certainty, I& #39;d likely opt for a pharmacy brand or premium brand digital. Even professionals who work in diagnostic labs make errors with LFDs. 
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